rvupgradestore.com Composet Products Fridge Defend
RV Life Magazine RV Park Reviews RV Trip Wizard

Author Topic: Building a new System  (Read 11849 times)

Kathy & Bill

  • ---
  • Posts: 95
Building a new System
« on: October 27, 2018, 09:26:06 PM »
We bought a new T.T. that fulfills our needs and most of our wants. It took going to many RV shows and countless hours searching floor plans online, but we are very happy with our Apex. It also has nice size tanks for dry camping which we like to do.

I would like to put together a DIY system for the electrical to enhance our dry camping experience. I would like to build it in two or three stages; batteries and battery monitor first; solar, charger and inverter or inverter/charger; then a generator. We will be retiring in a few years and want to have it set up for extended stays dry camping.

I'm planning on biting the bullet and go with the Battle-Born 100Ah 12V LiFePO4 batteries. I'd like have 400Ah total which will pretty much eat up the budget for the first stage. I was looking at the Victron BMV-712 Battery Monitor. Any advantage/disadvantage using this brand/model over another? Seems like the Tri-Metric TM-2030-RV is the other popular one.

The second stage would be the Solar system. My head starts spinning after a few hours of reading everything that goes a long with that. Good thing I still have some time to figure all that out. One thing that is nice about the Apex, it has some nice roof space for the solar panels.

What is the consensus of going with a separate inverter and charger, verses a inverter/charger combo?

Looking forward to upgrading small things on our camper to make it comfortable for us. We like camping at the federal campgrounds in Allegheny National Forest in PA. We like our space and always are looking for the secluded/out of the way campgrounds.

This is a great forum and have learned a lot reading different topics. Looking forward to hearing everyone's ideas related to my build.
Bill & Kathy
Western NY
2019 Coachman Apex 265RBSS
2012 Silverado 1500, 5.3L

Lou Schneider

  • Global Moderator
  • ---
  • *
  • Posts: 10328
Re: Building a new System
« Reply #1 on: October 28, 2018, 02:07:21 AM »
Good luck on your project - it sounds like fun!

Both the Tri-Metric and Victron do about the same things, Victron has an edge in that it can communicate via Bluetooth to your Smartphone, tablet or computer and has an app that makes it easier to see and manipulate the data compared to staring at that limited display on the unit.

One advantage to using a separate invverter/charger is cost if you already have a good converter/charger.  Another advantage is if you have limited electricity, like at a rally or plugged into a home outlet while driveway surfing, you can plug the converter into that outlet to keep the batteries charged, then use the inverter and batteries to supply bursts of power above the outlet's rating for things like microwaving a meal or using a hair dryer.  The charger won't draw more than it's rated input current from the AC line and batteries will act as the buffer when you need more power.

If you decide to go with a combo inverter/charger, I'd leave the RV's old converter connected on the 12 volt side and just disconnect it's AC feed.  Then if the inverter/charger ever has to be removed for service, you can use the old converter by plugging it into 120 volts.
« Last Edit: October 28, 2018, 02:22:26 AM by Lou Schneider »

kdbgoat

  • ---
  • Posts: 6313
Re: Building a new System
« Reply #2 on: October 28, 2018, 05:16:13 AM »
Some good reading:
http://marxrv.com
http://www.jackdanmayer.com/rv_electrical_and_solar.htm
https://handybobsolar.wordpress.com
And somemembers here, Solarman, Kevin Means, and HueyPilot, to name a few, has a lot of good advice,
I know you believe you understand what you think I said,
But I am not sure you realize what you heard is not what I meant

2012 Redwood 36RL
2016 Leprechaun 319DS

solarman

  • ---
  • Posts: 381
Re: Building a new System
« Reply #3 on: October 28, 2018, 07:14:11 PM »
We bought a new T.T. that fulfills our needs and most of our wants. It took going to many RV shows and countless hours searching floor plans online, but we are very happy with our Apex. It also has nice size tanks for dry camping which we like to do.

I would like to put together a DIY system for the electrical to enhance our dry camping experience. I would like to build it in two or three stages; batteries and battery monitor first; solar, charger and inverter or inverter/charger; then a generator. We will be retiring in a few years and want to have it set up for extended stays dry camping.

I'm planning on biting the bullet and go with the Battle-Born 100Ah 12V LiFePO4 batteries. I'd like have 400Ah total which will pretty much eat up the budget for the first stage. I was looking at the Victron BMV-712 Battery Monitor. Any advantage/disadvantage using this brand/model over another? Seems like the Tri-Metric TM-2030-RV is the other popular one.

The second stage would be the Solar system. My head starts spinning after a few hours of reading everything that goes a long with that. Good thing I still have some time to figure all that out. One thing that is nice about the Apex, it has some nice roof space for the solar panels.

What is the consensus of going with a separate inverter and charger, verses a inverter/charger combo?

Looking forward to upgrading small things on our camper to make it comfortable for us. We like camping at the federal campgrounds in Allegheny National Forest in PA. We like our space and always are looking for the secluded/out of the way campgrounds.

This is a great forum and have learned a lot reading different topics. Looking forward to hearing everyone's ideas related to my build.

I would suggest you not buy batteries first until you have at least performed a power budget and have a better idea of what you actually need.  I witness this "cart before the horse" engineering all the time, even by those qualified to know better..

ok, professional rant over.. LOL... seriously though, it would be better for you to have a good estimate of your actual needs rather
than just buying four of this or that..  I know it may seem to be an overkill to have a good estimate first, but it will pay off in the long run having a system better matched to your needs. ( and potentially a more economical solution )

I have a post here that explains solar and battery capacities..
http://www.rvforum.net/SMF_forum/index.php/topic,113514.0.html

also one thing you should be aware of with lithium is the limited temperature range.. if you intend to camp
in colder,freezing or sub zero weather then they are not a good choice unless you can install them inside the RV.
I have done this with mine for such a reason.

as for separate vs combo units.. it's down to reliability, cost and personal preference.

combo units take up less space generally and may include an automatic transfer switch too..
best of all worlds.. however, if you have not sized it correctly, then upgrading is more expensive vs individual units
as you have to replace everything in one go.. if space is not an issue then separate units will give you more flexability
in the event of failure.

KZ MXT20 480 W solar
ORV 24RKS 960 Watts solar
48V LFP, 2000W inverter/charger
Ram 2500 CTD

Kevin Means

  • ---
  • Posts: 4911
  • SolaRVector
    • SolaRVector
Re: Building a new System
« Reply #4 on: October 29, 2018, 01:03:06 PM »
I'll build a little on what Solarman recommended, because it's easy to spend a lot of money on batteries and be disappointed with the results. Good batteries can be expensive, so it's important to know how much capacity you need.

I'd recommend installing a battery monitor first - either one you mentioned would work fine. Then spend a day, or two, or whatever boondocking. Do all the things you'd normally do. Watch TV, run the lights, charge phones, tablets etc. then look at your battery monitor and see how many amps you've consumed. Both of those battery monitors will indicate (in percentage) how much battery capacity remains. 

Let's say you currently have a 200 AH battery bank, and after one day of camping (24 hours) your battery monitor indicates that you're at 50% capacity, without any type of charging. That means you've consumed 100 amps in 24 hours. It would be better to take repeated measurements over time and average the results.

Here's where battery choice starts getting important. Li batteries can be safely and repeatedly discharged to 20% capacity, but lead/acid batteries don't tolerate repeated deep discharges well. Repeatedly discharging them to even 50% will shorten their lives, especially if they aren't fully recharged soon thereafter. For what it's worth, I never discharge our AGM house batteries below 75% and our last set lasted seven years.

Using the numbers I mentioned, a 400 AH Li battery bank will go about three days before it needs recharging. If you're going to use lead/acid batteries, and you subscribe to my 75% philosophy, a 400 AH battery bank will last one day before it needs recharging. That's a big difference... but so is the price differential. Li batteries have other significant benefits as well, but they also have some drawbacks, like the temperature issue Solarman mentioned.

Once you understand your actual power consumption, which a battery monitor will indicate, then you'll have a better idea of how much battery capacity you'll need, and how much solar you'll want. You may decide that you don't even need a generator. We have a relatively high power consuming motorhome, and during our last two week-long boondocking trips, we never needed the generator at all. Solar handled all our charging needs.

Kev
« Last Edit: October 29, 2018, 01:09:58 PM by Kevin Means »
2011 Winnebago Tour 42QD
Towing a Jeep Rubicon Unlimited LJ
RVI Brake 2, TST 507 TPMS, 960 watts of solar, SolaRVector tilt
Lakeside, California

Kathy & Bill

  • ---
  • Posts: 95
Re: Building a new System
« Reply #5 on: October 29, 2018, 08:00:12 PM »
I thank you all for taking the time in writing the thought out replies.  I read the links posted, they were informative.

Solarman, Kevin.. doing a load assessment and figuring out what my usage is sounds like prudent advise.  Our new TT came with the usual 12v Marine/RV battery and is not equipped with an inverter... Yet.  I guess I would need some ideas on how to get my usage numbers?

I asked Battle-Born about purchasing.. say 2 of their batteries now and adding 2 more at a later date.  This is there reply;


"Thank you for your email and support on our batteries. We love our Customer’s and Customer Service is definitely our top priority!

To answer your questions, yes you can get 2 batteries now and then down the road 2 more batteries to add to your bank in parallel. We do have customer’s add to their bank up to 2 years down the road even. The reason why you are able to do this is because our lithium batteries do not lose their capacity as fast as say a lead acid battery. If you were to fully charge and discharge your 100AH battery every single day for a year your battery would only lose up to 3% of it’s capacity, so if you were to add a new 100AH battery to a battery that has 87AH’s you wouldn’t even notice a difference.

And yes, the only difference between the GC2 battery and the regular 100AH battery, are the dimensions. The only reason the GC2 is more expensive, is because they’re harder to build."


Does this sound like the proper advise?  If it is, I could install a battery monitor, purchase 2 batteries with an inverter, and be able to figure out my usage.  Maybe I'm overthinking or missing something easier.

Bill & Kathy
Western NY
2019 Coachman Apex 265RBSS
2012 Silverado 1500, 5.3L

solarman

  • ---
  • Posts: 381
Re: Building a new System
« Reply #6 on: October 30, 2018, 08:21:36 AM »
I thank you all for taking the time in writing the thought out replies.  I read the links posted, they were informative.

Solarman, Kevin.. doing a load assessment and figuring out what my usage is sounds like prudent advise.  Our new TT came with the usual 12v Marine/RV battery and is not equipped with an inverter... Yet.  I guess I would need some ideas on how to get my usage numbers?

I asked Battle-Born about purchasing.. say 2 of their batteries now and adding 2 more at a later date.  This is there reply;


"Thank you for your email and support on our batteries. We love our Customer’s and Customer Service is definitely our top priority!

To answer your questions, yes you can get 2 batteries now and then down the road 2 more batteries to add to your bank in parallel. We do have customer’s add to their bank up to 2 years down the road even. The reason why you are able to do this is because our lithium batteries do not lose their capacity as fast as say a lead acid battery. If you were to fully charge and discharge your 100AH battery every single day for a year your battery would only lose up to 3% of it’s capacity, so if you were to add a new 100AH battery to a battery that has 87AH’s you wouldn’t even notice a difference.

And yes, the only difference between the GC2 battery and the regular 100AH battery, are the dimensions. The only reason the GC2 is more expensive, is because they’re harder to build."


Does this sound like the proper advise?  If it is, I could install a battery monitor, purchase 2 batteries with an inverter, and be able to figure out my usage.  Maybe I'm overthinking or missing something easier.

personally, I'm suspicious of these claims..
I know a few guys who race golf carts and they use prismatic lithium cells in the 100 to 200 Ah range.
they usually start to loose capacity within 2 years, well short of manufacturer claims.
I don't know who's cells Battleborn uses, but even the best cells from A123 or Kokam have less than 2000 cycles when used heavily
I know the usage pattern is different, but the claims of high cycle life is questionable..
the only saving grace here with lithium is that they do parallel without issue unlike lead acid..
so you could add extra batteries at a later date, something one would never do with lead acid.. !

they claim 3% over 365 cycles.. the EV guys have measured 20% over two years ( 700 cycles or so )..
the only way I know to get the life they claim is to "over capacity" the cells, so the 100 Ah battery could well contain 120 Ah or more cells and the BMS prevents the user from over and under charging..
that way they CYA. very much like chevy and tesla do...

the only other issue I have with these drop-ins is the price.. certainly for me, I would expect premium performance from a $950 battery.
just to highlight how expensive these batteries are.. I recently had a quote for 240 Ah LFP cells at $168 each, delivered to my dock..
so 4 of them for 12 V would be $672  and that's 240 Ah.. !

so for me, "the jury is still out".. 

the other thing I would say is that unless you have space or weight constraints, you might like to re consider lead acid..
 
here is a comparison of cost for 12 V at 200 Ah  for current batteries:
lead acid is GC2 6V format and does not include useable DOD corrections.

Lead Acid    :  $200 total and $1.00/Ah
AGM           :  $472 total and $2.36/Ah
Battelborn   :  $1900 total and $9.5/Ah
Prizmatic    :  $672 total and $3.36/Ah

that's food for thought...


ok, on to measurement.. as Kevin suggested, get yourself a Victron or Trimetric and measure your use
over several days. that will get you the DC usage, next would be to estimate the appliance use such as the microwave, coffee maker etc.
those devices have defined wattage so we just need the "on time" estimate for each one and go from there.

« Last Edit: October 30, 2018, 08:29:01 AM by solarman »
KZ MXT20 480 W solar
ORV 24RKS 960 Watts solar
48V LFP, 2000W inverter/charger
Ram 2500 CTD

Kathy & Bill

  • ---
  • Posts: 95
Re: Building a new System
« Reply #7 on: October 31, 2018, 08:11:23 PM »

that's food for thought...


Good info to sort through and think about for sure.  I thank you for taking the time to post your detailed thoughts and expertise.  I guess with the Battleborn batteries you pay for convenience of "drop in" simplicity.  If I am correct, the BMS is built into the Battleborn's, where as batteries such as the Prizmatic you mentioned, need a BMS added to protect them?  When you are a novice as I am, you want a system that is easy to build and somewhat simple to use, you end up paying for it.  I'm not saying I have money to burn, but it is appealing to have a product you can "drop in" and hook up so to speak.

What do you think the chances are Battleborn did "over capacity" the cells.  What I've read about charging/discharging your assumption might make sense.

Question... When they talk cycles, does it matter the DOD % for a cycle?  In other words if you take the bank to a DOD of 80% and charge, or 20% DOD and charge.. each one is a cycle correct?

Winterized the camper last night.  I'll have to wait until next season to get our usage, it's going to be a long winter in Western NY El Niño or not.

Thanks again,
Bill
Bill & Kathy
Western NY
2019 Coachman Apex 265RBSS
2012 Silverado 1500, 5.3L

Lou Schneider

  • Global Moderator
  • ---
  • *
  • Posts: 10328
Re: Building a new System
« Reply #8 on: October 31, 2018, 08:19:00 PM »
Question... When they talk cycles, does it matter the DOD % for a cycle?  In other words if you take the bank to a DOD of 80% and charge, or 20% DOD and charge.. each one is a cycle correct?

It's more like how much total energy you move in and out of the battery over it's lifetime. 1000 cycles at 20% DOC moves the same amount of energy in and out of the battery as 250 cycles at 80% DOC.

It's not quite that cut and dry, but in general you get more shallow discharges or fewer deep discharges.   Your choice.
« Last Edit: October 31, 2018, 08:23:20 PM by Lou Schneider »

Kathy & Bill

  • ---
  • Posts: 95
Re: Building a new System
« Reply #9 on: November 01, 2018, 06:54:07 AM »
It's more like how much total energy you move in and out of the battery over it's lifetime. 1000 cycles at 20% DOC moves the same amount of energy in and out of the battery as 250 cycles at 80% DOC.

It's not quite that cut and dry, but in general you get more shallow discharges or fewer deep discharges.   Your choice.

Ok... that makes sense.  Thanks
Bill & Kathy
Western NY
2019 Coachman Apex 265RBSS
2012 Silverado 1500, 5.3L

solarman

  • ---
  • Posts: 381
Re: Building a new System
« Reply #10 on: November 02, 2018, 07:48:21 AM »
Good info to sort through and think about for sure.  I thank you for taking the time to post your detailed thoughts and expertise.  I guess with the Battleborn batteries you pay for convenience of "drop in" simplicity.  If I am correct, the BMS is built into the Battleborn's, where as batteries such as the Prizmatic you mentioned, need a BMS added to protect them?  When you are a novice as I am, you want a system that is easy to build and somewhat simple to use, you end up paying for it.  I'm not saying I have money to burn, but it is appealing to have a product you can "drop in" and hook up so to speak.

What do you think the chances are Battleborn did "over capacity" the cells.  What I've read about charging/discharging your assumption might make sense.

Question... When they talk cycles, does it matter the DOD % for a cycle?  In other words if you take the bank to a DOD of 80% and charge, or 20% DOD and charge.. each one is a cycle correct?

Winterized the camper last night.  I'll have to wait until next season to get our usage, it's going to be a long winter in Western NY El Niño or not.

Thanks again,
Bill

i'll bet there is a 100% chance they over spec.. they have to in order to meet lifetime claims, this is what chevy and tesla do.. they control the charge and discharge profile
to prevent the user from abusing the batteries, Tesla's cells have only a 400 to 500 cycle life, so they have no choice but to control every aspect of battery management.

battery cycles are limited to the technology, reversible chemical reactions within the cell are not symmetrical, so eventually the cell fails.

with drop-in's such as Battleborn, you are indeed paying a very high premium for convenience

the problem with drop-in's is the bms system, the only practical way to isolate the user from the underlying technology is to top balance the
cells, this is usually done with what we call a "vampire" board, the cells voltage during charging is measured and when it exceeds a certain value the
control system activates the board to steal some energy from the cell, limiting it's voltage. the idea is that eventually, all cells will reach this value and therefore
are now in a balanced state. the problem is that these boards have been shown to be unreliable and have a high probability of failing.

when I was contracting for NASA I discovered that they do not use any bms in their spacecraft, the extra weight and potential failure point is unacceptable.
they typically do a middle balance of the cells.. I personally do a bottom balance. fyi, my cells over an 18 month period have drifted by less than 1%
so for me, the effort of manually rebalancing the cells every 18 to 24 months is not an issue. that's easy for me to say as I have over 40 years as
an MSEE and PE. but for most people, they do not want or need to even know what is inside a battery, sometimes I wish I was one of those people. !!





KZ MXT20 480 W solar
ORV 24RKS 960 Watts solar
48V LFP, 2000W inverter/charger
Ram 2500 CTD

Kathy & Bill

  • ---
  • Posts: 95
Re: Building a new System
« Reply #11 on: November 03, 2018, 09:38:12 AM »
But for most people, they do not want or need to even know what is inside a battery, sometimes I wish I was one of those people. !!

lol... I hear ya.  Sometimes just knowing that it will work might be best.  My DW is glad I take the time and research things, although she thinks I over research at times.. she maybe right..  lol
Bill & Kathy
Western NY
2019 Coachman Apex 265RBSS
2012 Silverado 1500, 5.3L

Kathy & Bill

  • ---
  • Posts: 95
Re: Building a new System
« Reply #12 on: November 03, 2018, 10:35:09 AM »
Well... we will take a few more things out of the camper today, then it's ready for 5 months of hibernation in my friends barn.  WNY winters suck!!

While I was winterizing I figured out where I can install the inverter and batteries.  The 12 volt Li-on batteries will go under the foot of the bed.  The inverter will be about 4' away under the kitchen counter, I figure 7' or less of wire.  This (under the counter) is the only big void where I can hide the inverter, the electrical distribution is close by.. about 3' away.

With all that being said I have been looking at inverters.  LOTS of choices I see!!  I am wondering what the consensus is from members on the forum about brand, size and wave form?  I pretty much decided on pure-sine wave but would like to hear thoughts of others.

I have looked at the Magnum Energy MSH-3012M, it is a "hybrid" pure sine wave 3000 Watt inverter/charger/transfer switch all in one unit.  Getting a 3000 watt inverter might be overkill but it seems to have some nice features.  The "hybrid" feature seems like a neat idea if it works properly.  I haven't heard/seen any complaints online but not sure how long this technology has been on the market.  The other thing that is nice, you can add their BMS to the remote so all your info is in one place, a neater install.  Although I would be putting the cart ahead of the horse as far as the BMS.  I wouldn't have usage numbers until after I purchased the inverter.. lots to think about.

Interested in everyone's thoughts.  I have thick skin so you can be blunt, to a point. lol
Bill & Kathy
Western NY
2019 Coachman Apex 265RBSS
2012 Silverado 1500, 5.3L

schwyl

  • ---
  • Posts: 46
Re: Building a new System
« Reply #13 on: November 05, 2018, 09:08:25 AM »
Personally if you have a 30amp TT then I would look at a nice 3000 inverter/charger/transfer switch unit.

I have found that no matter how much you pay stuff is always going to break. You could try a cheaper model and you may be fine ( My buddy has been running one for 7 years now some no name knock off from ebay)

I would look at

Aims
Samlex
xantrex
Magnum
Gopower

and honestly theres so many just try not to buy the cheapest or the most expensive.

Edit:

I should add the reason why I say a 3000w inverter is so if your running off shore power its like the inverter is not even there when in pass through mode.  A lot of 2000w inverters only offer 20 amps while in pass through where the 3000w offer 30+ amps during pass through mode

So wiring it in to the trailer is simple. Just unhook the like to the panel wire it to the inverter ac in. Then run a new cable from the ac out on the inverter back to the panel and your done.

Also I would try to get the inverter much closer to the batteries. Close the better. Its better to have a long AC run than a DC run. I know trailer manufacturers dont even follow this but that is the best way
« Last Edit: November 05, 2018, 09:13:28 AM by schwyl »

solarman

  • ---
  • Posts: 381
Re: Building a new System
« Reply #14 on: November 06, 2018, 06:53:16 AM »
Personally if you have a 30amp TT then I would look at a nice 3000 inverter/charger/transfer switch unit.

Also I would try to get the inverter much closer to the batteries. Close the better. Its better to have a long AC run than a DC run. I know trailer manufacturers dont even follow this but that is the best way


I would strongly advise against a 3000 W unit, at 12 Volts you are getting into very high currents and very heavy cabling.

this highlights one of the biggest problems with low voltage systems, cabling and contact resistance have a big effect.

secondly, a 3000 W inverter has a high standby current, some as high as 30 to 40 Watts in idle mode.

thirdly, at full power and with 90% efficiency, you will need to supply ( 3000 * 1.1 ) / 12 = 277 Amps.  even using cable to 90 degree spec you will need better than 4/0
cables, also most DIY do not have the tools or experience to terminate cable lugs, you will need to have cables made by a marine or golf shop..
don't under estimate this, I have seen melted battery posts, lugs and cable from improper design..

additionally, at 90% efficiency, the inverter will need to dissipate close to 300 watts of heat, it should be in a ventilated area.

I suggest you scale it down to at most 2000 W, less idle draw and easier on cabling.

good units to consider are:

Victron Multiplus
Xantrex freedom XC2000
Samlex EVO-2212

these have 30 to 40 A transfer relays and good efficiency.
personally I would not consider the aims units, the quality is low compared to the others.




KZ MXT20 480 W solar
ORV 24RKS 960 Watts solar
48V LFP, 2000W inverter/charger
Ram 2500 CTD

schwyl

  • ---
  • Posts: 46
Re: Building a new System
« Reply #15 on: November 06, 2018, 08:49:11 AM »
Your right some do have the appropriate sized transfer relay to allow the full use of shore power.

Agreed most diy dont have the proper crimping tool required for the cabling but theres hundreds of online shops that will make the cable for you

Agreed with aims being on the lower end but people may be more apt to purchase based on price.



Kathy & Bill

  • ---
  • Posts: 95
Re: Building a new System
« Reply #16 on: November 09, 2018, 06:43:36 PM »

I would strongly advise against a 3000 W unit, at 12 Volts you are getting into very high currents and very heavy cabling.

The Magnum MSH-3012M is definitely bigger than we need.  It's physical size was appealing for where I was thinking of installing it.  The Victron Multiplus 2000VA should fit our needs, I had looked at it but wasn't sure it would fit where I'd like to install it.

Maybe installing the inverter under the bed next to the batteries would be better.  I wasn't sure about installing in that location but have seen other installs online that were similar.  Whether they were proper installs I guess is open for debate.

The planning continues.....
Bill & Kathy
Western NY
2019 Coachman Apex 265RBSS
2012 Silverado 1500, 5.3L

wmtired

  • ---
  • Posts: 73
Re: Building a new System
« Reply #17 on: November 09, 2018, 11:28:28 PM »
You can purchase a hydraulic crimper for heavy cable for less than $50.

For reasons previously mentioned, a combined inverter/charger with auto-transfer switch and load sharing is a nice feature if your budget can afford. it.

Yes, 3kw inverters have a large idle load it must be noted that inverter's are most efficient when they are operating at near max capacity.  Lower power loads equals less efficiency.  Some folks deal with this by using much smaller inverters for more common low loads (TV, DVD player, computer and printer etc...) and use the big inverter for microwave, vacuum, hair dryer, toaster oven, etc...

Battery monitor:  Victron is what I prefer although I have a trimetric.  The trimetric looks dated and something that was designed in the 70's.

Sounds like your system will be top notch once it is complete.





Kathy & Bill

  • ---
  • Posts: 95
Re: Building a new System
« Reply #18 on: November 10, 2018, 08:22:38 AM »
Some folks deal with this by using much smaller inverters for more common low loads (TV, DVD player, computer and printer etc...) and use the big inverter for microwave, vacuum, hair dryer, toaster oven, etc...

I hadn't thought about that.  That would work good for running my C-Pap at night.  I already have a 300 watt inverter that I used for that, then the bigger one could be turned off for the night.  If everything is under the bed, it would be an easy install.  Great idea... Thanks!
Bill & Kathy
Western NY
2019 Coachman Apex 265RBSS
2012 Silverado 1500, 5.3L

schwyl

  • ---
  • Posts: 46
Re: Building a new System
« Reply #19 on: November 10, 2018, 01:57:09 PM »
If trailer manufacturers weren't so shitty with their builds you could have an easy time adding a simple sub panel with a few low load drawing plugs and others and run off of a small inverter.

Then for the larger loads run through a larger sized inverted with a transfer switch.


Yes im taking a shot at forest river the company that ran both dc and ac wiring through a hole cut in metal with no sort of bushing allowing the electrical cables to rub against a jagged edge wearing through the insulation.

Oh yeah the call to the factory was a joke. I was told to fix it. I was secretly hoping that it would just cause a fire in the unit and burn the pos to the ground

Kathy & Bill

  • ---
  • Posts: 95
Re: Building a new System
« Reply #20 on: November 12, 2018, 04:07:44 PM »
It is a shame that manufacturers don't take a little more time when they build RV's.  The quality of workmanship is really lacking.

I'm a long ways from adding solar just yet but ran across these panels and wondered if anyone knew anything about them.. good or bad?
Bill & Kathy
Western NY
2019 Coachman Apex 265RBSS
2012 Silverado 1500, 5.3L

solarman

  • ---
  • Posts: 381
Re: Building a new System
« Reply #21 on: November 12, 2018, 08:38:58 PM »
It is a shame that manufacturers don't take a little more time when they build RV's.  The quality of workmanship is really lacking.

I'm a long ways from adding solar just yet but ran across these panels and wondered if anyone knew anything about them.. good or bad?

good well made panel, just low on efficiency therefore heavy for the wattage vs other makers

one benefit for diy from this supplier is the free postage vs other suppliers that charge an arm and a leg for shipping



« Last Edit: November 12, 2018, 08:44:28 PM by solarman »
KZ MXT20 480 W solar
ORV 24RKS 960 Watts solar
48V LFP, 2000W inverter/charger
Ram 2500 CTD

AStravelers

  • ---
  • Posts: 1452
  • Part time travelers, 4-8 months each year.
Re: Building a new System
« Reply #22 on: November 13, 2018, 05:12:04 PM »
I hadn't thought about that.  That would work good for running my C-Pap at night.  I already have a 300 watt inverter that I used for that, then the bigger one could be turned off for the night.  If everything is under the bed, it would be an easy install.  Great idea... Thanks!
About the CPAP:
--  Turn off the humidifier heater or heated hose and you will most likely find the CPAP pulls less than 1amp of 12V power.  The heater jumps the current to 4-7amps of 12V.
--  Check the actual voltage the CPAP actually uses.  Most (or many) use 12V or 24V.  There is a transformer in the 120V power cord to lower the voltage.  If 12V, just tap into the 12V light fixture at the head of the bed with a 12V outlet.  If 24V, you can buy a 12V to 24V converter which may be more efficient than an inverter.
--  If you find you can sleep w/o the humidifier heater, you can just wire a 100watt inverter into the light fixture and use that for the CPAP. 
Al & Sharon
2006 Winnebago Journey 36G
2020 Chevy Colorado 4X4 Diesel
650 watts residential solar panels--400AH Lithium batteries

http://downtheroadaroundthebend.blogspot.com/

AStravelers

  • ---
  • Posts: 1452
  • Part time travelers, 4-8 months each year.
Re: Building a new System
« Reply #23 on: November 13, 2018, 05:23:05 PM »
No matter where you install the inverter/charger, solar controller and batteries, you MUST have ventilation for removing the heat from the components.

Additionally inverters and solar controllers usually need space below and/or above for air circulation. This makes it difficult to mound under the bed.

Most mfg allow you to download the install and operations manual for the devices you are thinking of buying to see where you can mount them.
Al & Sharon
2006 Winnebago Journey 36G
2020 Chevy Colorado 4X4 Diesel
650 watts residential solar panels--400AH Lithium batteries

http://downtheroadaroundthebend.blogspot.com/

JDOnTheGo

  • ---
  • Posts: 425
    • JdFinley.com
Re: Building a new System
« Reply #24 on: November 16, 2018, 06:14:55 AM »
A few more thoughts for the OP.

Lithium batteries are MUCH lighter than lead acid. For example; My 10,000 Wh lithium bank weighs 230 lbs and measures 22” X 19”x 10”. I would need fourteen 6V batteries to achieve the same usable capacity. That would weigh approximately 1000 pounds and consume a lot of space. I realize you are not looking at that large of a bank so you'll have to do your own comparison.

Having lived with lithium for nearly two years, I love them.  That said, there is no doubt that they are not for everyone. In general, I'd say they are an unnecessary expense for weekenders, occasional users, and full hookup type campers. 
 
PSW inverter is always better (but not necessarily 'required'). Many/Most components will run on MSW but it is certainly not ideal.  Choose your inverters carefully, especially if putting one under your bed. IMO, many of them are terribly noisy (the cooling fans). The fans will always(??) come on when the inverter is working hard so no avoiding that.

JD - Full timer out west
Missy - 1998 MCI 102-EL3 - 1.7kW Solar - 10kWh Lithium
My Adventures & Build

Kathy & Bill

  • ---
  • Posts: 95
Re: Building a new System
« Reply #25 on: November 17, 2018, 05:03:15 PM »
No matter where you install the inverter/charger, solar controller and batteries, you MUST have ventilation for removing the heat from the components.

Additionally inverters and solar controllers usually need space below and/or above for air circulation. This makes it difficult to mound under the bed.

Most mfg allow you to download the install and operations manual for the devices you are thinking of buying to see where you can mount them.

I've been thinking about ventilation and contemplating several ideas.  My compartment under the bed is probably 3'x4' by 20" deep, should be no problem with air circulation.  Downloading the install manuals is a good idea, I thank you for your thoughts.
Bill & Kathy
Western NY
2019 Coachman Apex 265RBSS
2012 Silverado 1500, 5.3L

Kathy & Bill

  • ---
  • Posts: 95
Re: Building a new System
« Reply #26 on: November 17, 2018, 05:11:08 PM »
About the CPAP:
--  Turn off the humidifier heater or heated hose and you will most likely find the CPAP pulls less than 1amp of 12V power.  The heater jumps the current to 4-7amps of 12V.
--  Check the actual voltage the CPAP actually uses.  Most (or many) use 12V or 24V.  There is a transformer in the 120V power cord to lower the voltage.  If 12V, just tap into the 12V light fixture at the head of the bed with a 12V outlet.  If 24V, you can buy a 12V to 24V converter which may be more efficient than an inverter.
--  If you find you can sleep w/o the humidifier heater, you can just wire a 100watt inverter into the light fixture and use that for the CPAP.

I have a small portable CPAP I use for camping, no humidifier or heated hose.  The machine I use is 120V with no transformer in the power cord, it's basically a computer power cord.  This machine works fine for a week or so, but when we snowbird or fulltime it in a few years I will want humidification.
Bill & Kathy
Western NY
2019 Coachman Apex 265RBSS
2012 Silverado 1500, 5.3L

Kathy & Bill

  • ---
  • Posts: 95
Re: Building a new System
« Reply #27 on: November 17, 2018, 05:42:06 PM »
A few more thoughts for the OP.

Lithium batteries are MUCH lighter than lead acid. For example; My 10,000 Wh lithium bank weighs 230 lbs and measures 22” X 19”x 10”. I would need fourteen 6V batteries to achieve the same usable capacity. That would weigh approximately 1000 pounds and consume a lot of space. I realize you are not looking at that large of a bank so you'll have to do your own comparison.

Having lived with lithium for nearly two years, I love them.  That said, there is no doubt that they are not for everyone. In general, I'd say they are an unnecessary expense for weekenders, occasional users, and full hookup type campers. 
 
PSW inverter is always better (but not necessarily 'required'). Many/Most components will run on MSW but it is certainly not ideal.  Choose your inverters carefully, especially if putting one under your bed. IMO, many of them are terribly noisy (the cooling fans). The fans will always(??) come on when the inverter is working hard so no avoiding that.

The only place I have for lead acid batteries is on the tongue and I wouldn't be able to get enough AH's for what I want to do.  I guess I could put AGM's under the bed but then you have the weight which I'd like to stay away from.  Lithium seems like the answer for my install.

We enjoy the quite of campgrounds without hookups.  The Allegheny National Forest is close by and we take advantage of that many times during the summer months.  In a few years we hope to follow the weather and take advantage of BLM's out west when we retire.

I will be purchasing a PSW inverter, a little more money maybe but as you said "PSW inverter is always better".  I have thought about the noise factor under the bed and have a concern about that.  It should be at idle (or off) at night, or very low draw if I'm using it for my CPAP.
Bill & Kathy
Western NY
2019 Coachman Apex 265RBSS
2012 Silverado 1500, 5.3L

Kathy & Bill

  • ---
  • Posts: 95
Re: Building a new System
« Reply #28 on: November 17, 2018, 06:10:32 PM »
Up to this point I have been exploring a 12 volt system only.  I have seen 24 volt systems but they seem to be on big AH battery banks.  I really don't see myself going any bigger than 400 AH's but still need to do my power assessment.  If 400 AH's is my max, is there any reason to investigate a 24 volt system?

Seeings how I put the camper to bed in a friends barn for the winter, I will have to wait the 5 long months of Western NY winter before I can do a assessment or anything else for that matter.
Bill & Kathy
Western NY
2019 Coachman Apex 265RBSS
2012 Silverado 1500, 5.3L

JDOnTheGo

  • ---
  • Posts: 425
    • JdFinley.com
Re: Building a new System
« Reply #29 on: November 18, 2018, 04:31:08 AM »
If 400 AH's is my max, is there any reason to investigate a 24 volt system?

Given what has been said here, I would say no. 

I have a 24VDC bank and am very happy with it but, as you you've noted, it is supporting reasonably large loads AND high charge rates.
JD - Full timer out west
Missy - 1998 MCI 102-EL3 - 1.7kW Solar - 10kWh Lithium
My Adventures & Build