You get what you pay for.......

[Frank B]

Gary, the end user doesn't calibrate the shunt. You pretty much have to rely on the manufacturer for that and assume they did it right.
I'm not a Victron owner but I suspect that it has the capability to use different shunts by setting a programming parameter. I was suggesting that this parameter be checked to be sure it is correctly set. If it's not then the readings will be off. (See Lou's post).

K&B, I was trying to figure out how you run the batteries so low so fast. Now I see that you ran the A/C on inverter. You're gonna need a lot more battery and solar to do that. It's just not practical with current technology.

I agree with all but the very last statement.  


If I had two more GC-2's (8 total) or lithium batteries, and more cooling for my 2500 watt inverter, I could probably run the a/c during the heat of the day while the sun is shining (and charging @ 50+ amps thereby reducing the load on the batteries by close to 50%).  Could probably not do it continually day after day with 1260 watts of flat-mounted solar panels on our 30' TT.  But may I suggest that technology is no longer the limiting factor?  It is now just a question of capacity.

 

[Gary RV_Wizard]

But may I suggest that technology is no longer the limiting factor?  It is now just a question of capacity.

I think that is definitely the case.  It's a practical limitation, not a lack of technology.  If you are willing to spend the $$ and devote the space and weight to  sufficient panels and batteries, you can power most common 120v loads. Even 240v loads if its important.

 

[Lou Schneider]

Nomadic Fanatic on Youtube has been running his roof a/c on his solar and lithium battery installation for some time.  He gets several hours of runtime during the hottest part of the day.  I think his system cost around $10k.

 

[Old_Crow]

Nomadic Fanatic on Youtube has been running his roof a/c on his solar and lithium battery installation for some time.  He gets several hours of runtime during the hottest part of the day.  I think his system cost around $10k.

I could use my generator to run both my a/c's plus everything in my coach for a long freakin' time on $10k worth of gas.  Certainly longer than my holding tanks will last without attention.

 

[Dragginourbedaround]

I could use my generator to run both my a/c's plus everything in my coach for a long freakin' time on $10k worth of gas.  Certainly longer than my holding tanks will last without attention.

I guess he's more concerned with peace and quiet and has the deep pockets to afford that luxury.

 

[Boat Addict]

I am not sure how his got his setup up to 10K. I think he dealt with a new or rebuild generator, which may have been included in that number. I ended up with 525 watts of solar power, 2,000 watt inverter and controller which runs everything but the air. I spent about a grand total with group 31 deep cycle batteries. I have no intensions of trying to run the air . I cannot and will not add enough solar panels and spend for expensive batteries because of the lack of space. But also its just not needed. I have a generator if I really need the extra power. I have personally camped out west for two years now and the need for air from the Utah elevation and locations north was just not needed.

But the luxury of keeping the batteries up and getting up in my skivvies and fire up the coffee pot without going out and dealing with a portable generator is work the expenditure by itself.  And by the way Nomatic Fanatic is whiner Anyone that carries a portable hot tub and wants campers around him to join him in the tub is a bit odd, and would include spending 10K , which is just way out of the norm for the average camper.

 

[Ex-Calif]

$10,000 bucks for solar sounds crazy to me. We used to talk about "8 cubed" in the boat world. 8 batteries, 800 AH and 800W.

8 X 100W solar panels = $1,000
8 Trojan t105 225 ah @ 6V = $1,200
Victron solar charge controller & other bits = $500

I'd be hard pressed to spend $1500 on 66 amps of solar capacity...

You have to be a "little" careful with the energy budget but this is pretty much energy independence for a liveaboard boat.

Engine alternator and a diesel generator provide backup. Diesel genny provides 115V if/when needed. We'd run the A/C around dinner time for an hour to cool the cabin and allow microwave use and coffee pot if desired.

 

[Lou Schneider]

OK, now that I reviewed his installation it's more like $5k plus installation.  1280 watts solar panels (4x320 watts).  Victron Multiplus 3Kw inverter, MPPT charge controller and battery monitor.  3 Battle Born lithium batteries. Wire, disconnects, etc.  Still a pretty good chunk of change.

 

[Ex-Calif]

OK, now that I reviewed his installation it's more like $5k plus installation.  1280 watts solar panels (4x320 watts).  Victron Multiplus 3Kw inverter, MPPT charge controller and battery monitor.  3 Battle Born lithium batteries. Wire, disconnects, etc.  Still a pretty good chunk of change.

Lithium batteries explains a lot.

I'm not there yet with Lithium life cycle cost.

Trojans can last 10 years properly maintained for a cost of like $120 a year.

I'd need 3X the life to justify lithiums recognizing the advantages of charge rates etc.

 

[Lou Schneider]

On the plus side, 3 100 ah lithium batteries can support the draw of his rooftop a/c through the inverter.  Probably something like 50 amps out of them for 4-6 hours without voltage sag after subtracting the contribution of his flat mounted 1280 watt panels.

 

[Ex-Calif]

Yup - I guess that's true. If you believe the lifing story the Lithiums are good for 500 deep cycles.

Lets say he gets 3 years out of them. That's probably $1,000 a year in battery cost or $80 a month.

I'll run the genny in the evenings to cool down the RV and pretty much don't need to heat my hot tub - LOL...

 

[Lou Schneider]

Yup - I guess that's true. If you believe the lifing story the Lithiums are good for 500 deep cycles.

Lets say he gets 3 years out of them. That's probably $1,000 a year in battery cost or $80 a month.

500 deep cycles is an understatement.

Battle Born says their batteries retain 70-80% capacity over 3000 cycles and they've seen over 5000 cycles in their lab tests.  They come with a 10 year warranty.

I bought two Lion Safari batteries at Costco for $700 each.  They came with lifetime warranties and an expected life of at least 3500 cycles.  With 100 a/h usable capacity each one has about the same performance as a pair of lead acid golf cart batteries.

Both Battle Born and Lion Safari batteries are rated for up to 100 amps continuous discharge.  That's a C/1 rate, or delivering maximum power from full to empty in one hour.

A 3500 cycle lifetime brings the cost per year down significantly.  If you keep them long term the overall cost can be lower than lead acid.  In my case, $700 divided by 10 years is $70 a year per battery.  Less if they last longer than 10 years.

 

[Tom55555]

I'm normally plugged in or my primary motor is on, both of which charges the coach battery.

When we boondock my wife and I use our cellular hot spot phones and tablets. I can't even remember when our standard 100 Ah deep cycle lead acid battery got low enough where the inverter beeped. It would only run our TV and DVD for about 2 hours.

The AC, microwave, coffee maker, electric skillet or hair dryer needs the generator but other than that the battery lasts a long time. The thing is you start the generator for a while to run an appliance and it tops off the coach battery.

To me, lithium is about weight. I use them on our e-bikes. Went from 20 pound SLA to 4 pound lithium with twice the power and more power cycles.

Hard to beat a generator. I know fossil fuels aren't popular with our younger generations but 55 gallons of gas an 18 gallons of propane lasts a long time and you're independent of the sun and wind which you have no control over.

 

[Frank B]

I'm normally plugged in or my primary motor is on, both of which charges the coach battery.

When we boondock my wife and I use our cellular hot spot phones and tablets. I can't even remember when our standard 100 Ah deep cycle lead acid battery got low enough where the inverter beeped. It would only run our TV and DVD for about 2 hours.

The AC, microwave, coffee maker, electric skillet or hair dryer needs the generator but other than that the battery lasts a long time. The thing is you start the generator for a while to run an appliance and it tops off the coach battery.

To me, lithium is about weight. I use them on our e-bikes. Went from 20 pound SLA to 4 pound lithium with twice the power and more power cycles.

Hard to beat a generator. I know fossil fuels aren't popular with our younger generations but 55 gallons of gas an 18 gallons of propane lasts a long time and you're independent of the sun and wind which you have no control over.

Unless you crave quiet, as we do. 


We boondock almost exclusively in order to get the quiet.  The kind of quiet where the noise of the flame in the fridge is an annoyance.    Yes, I have a 10 year old Honda eu2000i, but I doubt it has 50 hours on it yet.  As others have noted, snowbirds don't often need an a/c, as we travel south in the winter when soaring temperatures are less common.


As to the $10k solar system, yeah, that seems somewhat excessive.  But if you PAY someone to design and install for you, and cost is no object, then people will line up to take your money.  Solar has been 'the wild wild west' up until recently, so "stick 'em up."    And, there is the little item called 'ostentation' to consider as well.


I installed my own 1230 watt system easily on the roof of our 30' TT for somewhere in the neighbourhood of $2500 CDN including freight.  6 x 205 watt flat-mounted panels mean about 600 watts usable, which is more than enough for our needs, and ALMOST enough to run the a/c.  But, that was never an issue for us, and we've never run the a/c when south in Arizona over the past 4 or 5 years anytime from November through March.


We run our microwave, hair dryer, pop up toaster, Tassimo coffee maker (sometimes), hot-air popcorn popper, and various other sundry appliances off the solar and 2500 watt inverter.  Typically, we are back to 100% charge by 1 PM every sunny day.  Can't quite do it by end of day when cloudy or rainy, but we are never short of solar power.


And, running the generator for a short time while using a hair dryer or whatever is unlikely to 'top off' any lead acid battery.  The last 20% or so of charge on a lead acid (absorb stage) takes a LONG time at low current.  This is perfect for solar, but not so much for a generator.


Anyway, to each his own.  It is so nice that the RV community has so many options these days.  There is something to fit every budget and use case scenario.  So have fun!  But if you do go solar, put WAY MORE on the roof than you think you will need.  No one ever complains of having too much solar.   The cost difference between installing 4 or 6 panels is a trivial amount compared to the total cost of the system.


Frank.

 

[Boat Addict]

Nomadic Fanatic on Youtube has been running his roof a/c on his solar and lithium battery installation for some time.  He gets several hours of runtime during the hottest part of the day.  I think his system cost around $10k.

FYI he has upgraded his grocery vehicle from the cycle to a Smart Car, naming it "Tater Tot"  8) He did not say if he planned on converting it to solar.