Best deep cycle ?

tplife wrote:
While certainly a top-line flooded battery, Trojan (and other manufacturers) offers AGM options that are far superior to flooded batteries - if your budget can afford it. Like any other piece of high-end gear, if you use it, you will get more than the cost out of it on the back end for cost-efficiency.

Battery Type Comparisons

I read this article. He compared many battery types (FLAs, AGMS, etc.) and came to the conclusion that AGMs are best for his use on a boat.

However, I had serious doubts about that conclusion.

1) He did a comparison of energy vs battery volume and found that flooded lead acids (FLA) specifically, Trojan T-105s were by far the best.

2) He did an energy storage vs. weight comparison and again found that FLA/Trojans were by far the best

3) Then he did a purchase cost comparison vs capacity. Again the FLAs won.

4) Finally, he did a lifetime total cost comparison and found that AGMs won. The method of comparison, however, was odd. He assumed you would run an engine to charge the batteries and compared the cost of running his diesel engine to charge the different batteries. It's expensive to buy gas/diesel to run an engine to charge with the alternator, so this analysis made the most important factor the charge rate - i.e. the size of the engine alternator and its current output.

The faster you recharged, the less you had to run the engine and the lower the cost. That might apply for a boat, but might not apply to your RV. It also might not apply if your charge system can't get into the above 100A charge rate region where the advantage is greatest. Finally, he ignored the decreased charge rate after you leave bulk rate. He assumed the bulk rate charge would continue through the charge cycle. Many of us spend a lot of time in absorption, not bulk, so even with a large charger, his analysis was off. It doesn't shorten charge time to have a big charger if the battery won't accept the high charge rate the charger is capable of.

Further, he had some comments about charging and discharging that I didn't agree with. There was a lot of discussion of Peukert, but it wasn't well thought out IMHO. The Peukert exponent is specific to a constant discharge until a certain voltage is reached during discharge. In reality, the Peukert exponent has two factors - one is the energy loss due to internal battery resistance - the I squared R power loss. The other, however is not a true energy loss. The battery voltage will recover if allowed to sit, and some energy appears to be lost can still be recovered if you are willing to draw out the last bits more slowly and after a recovery period. He heavily weighted the lower internal resistance of AGMs in a way that i don't think RV battery usage merits.


Finally, he disagreed with another expert on battery usage in boats who recommended charging in parallel and discharging individually, instead of in a parallel bank, where possible. I agree with the other expert. There are good reasons why discharging a parallel bank is harder on the bank than charging a parallel connected bank, and he didn't seem to understand that. (I don't do that - I discharge in parallel, but that's because it's hard to set up to discharge individually. Nonetheless, I understand why it's easier on the batteries to discharge individually, where possible.)

In general, he had lots of good info in that link, but I didn't agree with the conclusions and didn't trust his understanding of the data he posted. Still, it's worth a read.

My personal opinion is still that FLAs, such as Sam's Club 6v's are the best bank for the buck. Some of us are willing to pay more for less hassle - no water checks. Some need the reduced gas venting of AGMs or the ability to mount them on their side, etc., and some can use the faster recharge rates if they have a small battery bank and a big charger. However, for me, the bang for buck is the prime concern and FLAs can't be beat.

I "BEST" stay out of this...

While certainly a top-line flooded battery, Trojan (and other manufacturers) offers AGM options that are far superior to flooded batteries - if your budget can afford it. Like any other piece of high-end gear, if you use it, you will get more than the cost out of it on the back end for cost-efficiency.

Battery Type Comparisons

MEXICOWANDERER wrote:
"Best" is an incomplete description. It needs to be followed by more words..

Like "FOR"

"VALUE"

"WARRANTY"

"PERFORMING"

"PRICE"

Just using the one word is like saying the federal government is the "best..."

(Choose One)

Actually the "best battery" no longer exists because no one is willing to pay for it.

Some excellent quality batteries have been mentioned but the "best" currently available would probably be a bank of lithium ion batteries. But then again, who will pay the price of admission?

"Best" is an incomplete description. It needs to be followed by more words..

Like "FOR"

"VALUE"

"WARRANTY"

"PERFORMING"

"PRICE"

Just using the one word is like saying the federal government is the "best..."

(Choose One)

Used Ever Starts, WM, etc. GC has T-105's into year 8 still going weakly at about 1/3 of new run times but we just got one more year out of them. A few cells are drinking on the heavy side.

Been using Interstate Dist locally for DC and starting batteries if they are open when I get in the buying mood because they offer great service and have fresh stuff and try to under sell me on getting a new one.

I have run many of off road trips with my three standard issue Interstate 85AH batteries in parallel (255AHs) on my off-road POPUP. I would think getting setup with around 450AH to 500AH battery banks would be the ultimate battery power capability based on what I have done over the past 5-6 years camping off the power grid.

For the causal off-road camper just a couple of 12VDC batteries (200AH or so) should do the trick.

Takes planning and to be successful you have to recharge the batteries every day using a 2KW generator or solar panels.

Roy Ken

westend wrote:
Best wet cell, probably one of these Rolls Batteries.

X2

Best wet cell, probably one of these Rolls Batteries.
Best for your use may be a Trojan. Cheaper, will be a Costco or Sam's club offering. If you find battery maintenance isn't your thing, a Sears AGM battery might be a good choice.

Wow 2 6 volts....Awesome.....That would be the ultimate....on a pop up...Thanks:B