Battery capacity

No one will blame you for eschewing a generator. Take the undercharged batteries home and socketoem with public power. Hassle versus money here it is worthwhile to discharge to 40% state of charge.

Thanks, guys. For now, I'm sticking with my OEM charge controller, but plan on adding a 100w portable solar charger to give me an extra day or two. Biggest continuous draw on this new rig will be the fridge fans, since it's in a slideout. This does concern me and I really don't want to schlep along a genny for a 4-day 'docker, nor do I want to fire up the Duramax for a couple hours a day. =Nobody= would be happy with me for that! :B As I said, I'd =love= to build a Li battery pack, but need to win the lottery, first.

FWIW, my cousin's build blog on their bus is: www.beginningfromthismorning.com. Lots and lots of details and videos.

Lyle

First there are two "Longivity" issues
How long does a re-charge last (and you nailed that one)
how long does the battery last...

A slower recharge, relative to the battery capacity, up to a point, equals longer Battery Life.

Fact. My original batteries were Interstate U-2200's 220 amp hours
I had to water them every mother's day

My NEW batteries (the original lasted 9 years with some abuse) are 230 amp hour DEKA's.. missed 4 years without watering by a couple months.

I have added to the battery bank some but the slower recharge .. Relative to capacity (now over 500 amp hours for the entire setup) means longer battery life. EVEN after expansion I still had to water the Interstates annually . and as they aged more often.

Lyle - If you're going for price to AH capacity as the deciding factor, then hard to beat the Sams GC2's.

If you are more concerned about AH capacity vs price, then look to see if the Trojan T-125 or T-145 will fit. I also know a few who had the room and changed to the Trojan 12V T-1275 Plus. X's 2 will yield 300AH's capacity.

Sams GC2's are the easy and relatively disposable price point approach from both a budget point, and from a point of not being overly concerned on having higher AH capacity.

The mentioned Trojan's are the easy choice to maximize AH capacity in limited space, and with a wallet hurting capability:)!

That higher price point for the Trojans say over the Sams GC2's, will probably yield more life usage, so some of those higher costs could be recaptured 'if' the batteries due yield longer life:)!

(Stayed with Wet Cells here, obviously other choices of brands and battery types when you jump to AGM's.)

No right or wrong answer here, it's about your usage and budget points:)!

Best to you,
Smitty

skipro3 wrote:
I made the same decision when I bought mine from SAM's. Just too steep a price for the minimal increase in battery capacity in my opinion.

As far as the L16's, they are too tall to fit just about any place and it's putting all your eggs in one basket; if one fails, you are screwed. 4 GC-style batteries are not going to leave you without power if one of them decides to act up. And for the price of L16's, it's getting real close to LiFePo batteries that can be drained down to 20% and weigh half as much as flooded. (Besides zero maintenance and able to be mounted in any direction.)

I'd =love= to do as my cousin and her husband are doing, and make up a Li battery from Nissan Leaf modules. Problem is cost, which would be about 10x that of 6v battery install.

Lyle

I made the same decision when I bought mine from SAM's. Just too steep a price for the minimal increase in battery capacity in my opinion.

As far as the L16's, they are too tall to fit just about any place and it's putting all your eggs in one basket; if one fails, you are screwed. 4 GC-style batteries are not going to leave you without power if one of them decides to act up. And for the price of L16's, it's getting real close to LiFePo batteries that can be drained down to 20% and weigh half as much as flooded. (Besides zero maintenance and able to be mounted in any direction.)

After further research, the 230 ah battery has a much worse rating than the 215. NOT worth the price difference, so I'm not willing to spend that much more money for a chancy product.

FWIW, it's the 2 6v GC2 Duracells at Sam's.

Lyle

what brand ?, how much per pair

i'll bet that the $70 price increase is more than 7.5% of the 215 amphr price

meaning less bang for the buck when going bigger

7.5% is really pretty much the difference.

Some minor ancillary differences:
- For a given daily amp-hr consumption, the bigger bank will recharge slightly faster but not enough to get excited about.
- If you are running heavy loads, you do get more than the 7.5% due to the pureket effect but for the size you aren't going to be running heavy loads, so this won't be noticeable.

Brand of battery will make 2x times the "difference" in longevity. What you are not seeing is the 100-hour rate.

And a pair of L16 420 amp hour batteries will simply outperform 4 GC220 batteries.

So bottom line is don't lean on spec numbers too hard.