I Chickened Out

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Kevin Means

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Joined
Aug 3, 2010
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Hereford, Arizona
Our house-batteries get a pretty decent workout, because most of our camping is boondocking. Over the past several trips, however, our Trimetric has indicated a lower SOC in the morning than what I normally see (65-70% vs. 75-80% SOC) despite fairly common consumption. I'm pretty sure they were also taking longer to fully charge, but I never actually measured that - I'm just real familiar with their behavior.

We have eight 12 volt AGM house-batteries, six of which are a little more than seven years old. I added two additional AGMs to the house bank about a year and a half ago, and I'm pretty confident that those two are still in good shape, but it's time to replace the six original house-batteries.

Man I really wanted to go lithium. I read more battery reviews, studied more battery specs and read more opinion papers than you could shake a stick at, but in the end, I stayed with AGMs. It just came down to the initial cost - plain and simple - $1800.00 for six new AGMs (for a total of 840 AH with my two good batteries) or $7500.00 for six LI batteries (for a total of 600 AH.)

I had some other minor concerns, but had the price been more palatable, I'd have made the leap. There are a lot of benefits to LI batteries - especially for boondockers with solar. If we still own this RV in seven years, I'm quite sure the price of LI will be significantly lower, or maybe they'll have RV fusion reactors figured out by then. :D

Kev
 
Given the price, I haven?t done a lot of study of lithium, what I have read is enough to put me off. My biggest concern would be the charging limitations under certain ambient temperatures.  Not bringing the batteries inside, and no way to ensure the battery compartment temp is always correct. Plus, I?ve read a few reviews which seem to call the extended service life of lithium into question.


Running 4 Trojan flooded now, next set will be 6-8 AGM with the extras in an adjacent bin.
 
I'm envious of that battery capacity.

I'd have to trade my toad for a trailer to haul around that much weight!

Tom
 
You are still way ahead of me Kev. I am still rocking the six 6 volt wet cells. But I don't dry camp anywhere near as much as you do. In fact, I will have to be sure to set far enough from everyone at Quartzite this year when I run my generator a few times a day to keep the lights on........
 
Hi Kev,

Kevin Means said:
$1800.00 for six new AGMs (for a total of 840 AH with my two good batteries) or $7500.00 for six LI batteries (for a total of 600 AH.)

I think you got a good price on the AGMs (which brand/type, btw? Just curious) and a not so good price on the LiFePO4s: BattleBorn's 100Ah  can be had for less than $950 each with free shipping included (so your total would be less than $5700). And they are supposed to be plug-compatible with Lead-Acids so no modification to your RV electrical systems would be needed. Given that you'd be able to use at least 85% of their capacity (on the very conservative charge-up-to 95%, drain-down-to-10% rule), you'd have 510Ah available, handily beating the 420Ah (50% of 840Ah) you get from the 8 AGMs. To say nothing of the other advantages of LiFePO4s (reduced weight, faster charging, no Peukert effect, etc). And as they are expected to last 3000 cycles *minimum* (compared to what, 1000 cycles *maximum* that can be nursed from AGMs?), in the end their cost/year would almost match.

I'm not trying to second-guess (much less criticize) your decision, which I actually find a very good one -- on large expenses like these, it's always better to "err" on the side of caution. Just sounding out some ideas...

Cheers,
--
  Vall.
 
I am looking to make the next modification to my Auxiliary Battery Bank.

The switching change lets me convert the golf cart batteries from 36 volt to 12 volt and back within seconds.

I added a 4 gauge jumper with heavy duty 175 amp connectors to link the 6 batteries to either one of the other banks, (Stacker or DP).

I now realize that I can use two jumpers and put the golf cart between the two battery banks and have all 14 linked into one big bank with charging coming from all the panels and charge controllers. 

This gives me 1540 Amp Hours of  12 volt power with 1500 watts of panels coming thru 4 charge controllers, (160 amps).

I might give my backup generator away at Q.

I will show this at the rally.
 
Just for the "heck" of it I priced Li Batteries yesterday.. After retuirning from where I had to sit after readin the price.. I'll pass as well

I got asbotu 2200 dollars to replace one 220 dollar pair of Lead Acid.  They are not worth 10x the price, they are barley worth 2x the price if that.
 
SargeW said:
I will have to be sure to set far enough from everyone at Quartzite this year when I run my generator a few times a day to keep the lights on........

Then we'll be neighbors at Q

I can envision coaches assigned spots according to an equation with AH and solar capacity.

My case will have to factor in how many hours DW will require Dish Network.  ;)

Tom
 
Kevin Means said:
Our house-batteries get a pretty decent workout, because most of our camping is boondocking. Over the past several trips, however, our Trimetric has indicated a lower SOC in the morning than what I normally see (65-70% vs. 75-80% SOC) despite fairly common consumption. I'm pretty sure they were also taking longer to fully charge, but I never actually measured that - I'm just real familiar with their behavior.

We have eight 12 volt AGM house-batteries, six of which are a little more than seven years old. I added two additional AGMs to the house bank about a year and a half ago, and I'm pretty confident that those two are still in good shape, but it's time to replace the six original house-batteries.

Man I really wanted to go lithium. I read more battery reviews, studied more battery specs and read more opinion papers than you could shake a stick at, but in the end, I stayed with AGMs. It just came down to the initial cost - plain and simple - $1800.00 for six new AGMs (for a total of 840 AH with my two good batteries) or $7500.00 for six LI batteries (for a total of 600 AH.)

I had some other minor concerns, but had the price been more palatable, I'd have made the leap. There are a lot of benefits to LI batteries - especially for boondockers with solar. If we still own this RV in seven years, I'm quite sure the price of LI will be significantly lower, or maybe they'll have RV fusion reactors figured out by then. :D

Kev
Not chicken at all Kev. You did the research and made a sound decision. Li's are simply too pricey for me even considering the upside!
Hope you all are warm and safe on this great day. I just finished moving snow so we can be with family later.
18F here as we speak.
Peace!
 
Thanks Jeff. Yeah, it rarely ever gets cold enough in San Diego to complain. I'd be embarrassed after reading about some of the temps others here have to deal with. Winterizing an RV in Southern California usually just means turning your air conditioner from high to low.

Vall... the AGMs I bought are sold by NAPA and are made by East Penn. They list at $306.00 each and are commercial batteries, so they have to be special ordered. The nearest ones were in Dallas and I'm just hoping they arrive before our trip to KOFA early next month. They're the same 105 AH batteries Winnie installs at the factory.

Kev
 
Surprised that nobody closer had an identical DEKA AGM, or at least able to get them in a couple days from their distributor. Same battery (Deka is East Penn's own house brand).  NAPA is usually great, but they have to order through their own NAPA distribution network so real specialty items can take awhile.
 
If you are ever in Eastern PA, near Reading, you can go to the East Penn plant in Lyons, PA and get "blemishes" at their factory store for about 50% off. I've been buying all my batteries there for years. Used to farm and had my own 18 wheeler when we lived in eastern PA, so I did go through a lot of batteries. Our Monaco has 8 GC-15 batteries I got there 4 years ago for $54.00 each.
 
OK... Now you guys have gone and made me think!  LOL  Has anyone researched using the battery packs from hybrid vehicles in our motor homes/trailers? We have a Ford C-Max that got me thinking about voltage & amp hours used in these batteries. Just doing a quick search I found a couple links I thought I would share. Obviously, they vary greatly from vehicle to vehicle. Could any of you guys/gals with engineering knowledge shed some light on the feasibility of converting these for our use? Wrecking yards must have 1000's of these batteries that could be used.
  http://www.electricvehiclewiki.com/Battery_specs

  https://cleantechnica.com/2016/01/06/a-tale-of-3-battery-packs/
 
Car power packs run at 350-400 volts, so you'd have to break them down and rewire them to work at 12 volts.  Then you'd have to re-do the charge protection circuits to work at the lower voltages.

Tesla uses hundreds of 1.2 volt 18650 cells, just slightly larger than AA cells, in their batteries.  These are also used in laptop computer batteries.

Several people have used salvaged 18650 cells to make their own Tesla Powerwalls:

https://motherboard.vice.com/en_us/article/kzz7zm/diy-powerwall-builders-are-using-recycled-laptop-batteries-to-power-their-homes

One guy has also used them to power his electric VW bus conversion:

http://www.electricsamba.com/

Google 'Homemade Tesla Powerwall" for more examples.  ;)
 
Now, here is another thought. Sorry if this is TOTALLY off the wall! But, what IF... the car battery pack was a completely separate power system? Say to power the residential fridge and heavy load type appliances. Would the 350- 400 volt pack invert power more efficiently to AC power than the 12 volt we are working with? A person could leave the factory 12v system in place to power lights and light draw items. Since, we as RV'ers are in a continual quest for a better, cost effective, longer lasting power supply. I mean people are putting out a lot of money working with what we have now. Why not take advantage of these power packs that manufacturers have put so much R&D into.
 
Kevin Means said:
Our house-batteries get a pretty decent workout, because most of our camping is boondocking. Over the past several trips, however, our Trimetric has indicated a lower SOC in the morning than what I normally see (65-70% vs. 75-80% SOC) despite fairly common consumption. I'm pretty sure they were also taking longer to fully charge, but I never actually measured that - I'm just real familiar with their behavior.

We have eight 12 volt AGM house-batteries, six of which are a little more than seven years old. I added two additional AGMs to the house bank about a year and a half ago, and I'm pretty confident that those two are still in good shape, but it's time to replace the six original house-batteries.

Man I really wanted to go lithium. I read more battery reviews, studied more battery specs and read more opinion papers than you could shake a stick at, but in the end, I stayed with AGMs. It just came down to the initial cost - plain and simple - $1800.00 for six new AGMs (for a total of 840 AH with my two good batteries) or $7500.00 for six LI batteries (for a total of 600 AH.)

I had some other minor concerns, but had the price been more palatable, I'd have made the leap. There are a lot of benefits to LI batteries - especially for boondockers with solar. If we still own this RV in seven years, I'm quite sure the price of LI will be significantly lower, or maybe they'll have RV fusion reactors figured out by then. :D

Kev

Kev, No question it is a big investment and before we decided to go fulltime I could not justify the price either.  Not sure if this would have made a difference and I see you already purchased the AGM's,  but these are the ones we purchased and I see they are being offered at about $30.00 less per battery than when we bought ours. 
https://battlebornbatteries.com/shop/12v-lifepo4-deep-cycle-battery/ So still salty, no doubt, but better than what you were quoted.  So yes the price appears to be coming down, although in some places I have read, prices are at or close to where they will likely level out.  In the mean time I guess we will be your guniea pig to see how they perform over time.  Another factor in favor for us in deciding to take the leap, but perhaps not a concern for you given your rig, is battery weight.  Our TC is a monster so we have to be mindful of weight and the weight savings of the Lithium was huge.  The original AGM's that came with our TC were 2-90 AH batteries, we were able to get 3-100ah LI and saved approximately 30 pounds.  I am sure you will get good service from your AGM's though.

 
99dart said:
OK... Now you guys have gone and made me think!  LOL  Has anyone researched using the battery packs from hybrid vehicles in our motor homes/trailers? We have a Ford C-Max that got me thinking about voltage & amp hours used in these batteries. Just doing a quick search I found a couple links I thought I would share. Obviously, they vary greatly from vehicle to vehicle. Could any of you guys/gals with engineering knowledge shed some light on the feasibility of converting these for our use? Wrecking yards must have 1000's of these batteries that could be used.
  http://www.electricvehiclewiki.com/Battery_specs

  https://cleantechnica.com/2016/01/06/a-tale-of-3-battery-packs/

I seem to recall reading or seeing a video on someone who has done just that, but for the life of me I cannot recall the source.  If I can find it I will post it here.  It does sound doable though and presents an interesting idea.
 

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