Group 27 or 24 batteries

[guest2]

Hi everyone ,
Our used coach originally had a group 27 battery. The dealer cheaped out and put in a group 24.
We are looking to start dry camping with my brother in law and sister in law.
Question is should I go with a new group 27 or dual group 24 batteries? Only have room for two 24s or one 27. I’ll have a portable generator also.
Rich

[Scott'n'Wendy]

If it were me I'd replace the plan of having two FLA batteries with one LiFePO4 100ah battery. You will have approximately the same amount of battery power, longer life battery and quite a weight savings...but you didn't ask that......so...
Between the choices you offered, I would install parallel group 24's.

[howson]

guest2 (Rich) -- I'll also urge you to consider a LifePO4 battery.

The chart below was assembled for a presentation at the National Rally last year. It (hopefully) communicates why the initial price may be more for a LifePO4, but if the lifetime cost is much less (per usable watt hour). Especially for a boondocking use case.

Howard

[Country Campers]

I would like to have 2 batteries for redundancy, lithium or wet cell, just in case. I would agree 2 group 24's or 2 lithium. For dry camping or even any old camping the lithium is a game changer.

Brian

[Cate&Rob]

In addition to the chart posted by howson Howard in post #3, wet cell and AGM lead/acid batteries take a long time to accept charge above 80%. Plus, they should not be discharged below 40/50%. Thus, unless you are willing to run the generator for an extended time period, for dry camping you should factor your battery usage within 30% of the nameplate capacity (80% - 50%). For Lifepo4 batteries, this reasonable recharge time (with an appropriate charger/converter) is 80% or more of the nameplate capacity.

Rob

[Sandridge4]

I would also go with two batteries vs. one. Also agree that lithium is definitely the way to go. We just finished a week in Quartzsite which was our first boondocking trip after converting to lithium. It was so nice not having to really worry about battery power. With our solar and new batteries we never needed the generator, watched tv, made coffee, ran a cpap all night and no generator! This is the brand we installed and couldn’t be happier. https://www.litime.com/collections/12v-batteries

[TucsonJim]

To directly answer your question, I'd go with two group 24 batteries. Here's why:

Useable amp hour capacity for a group 27 battery: 44Ah (88Ah x 50%).
Useable amp hour capacity for two group 24 batteries: 81Ah. (2 x 81Ah x 50%)

Price: Interstate Group 27 $159.95
Price: Interstate Group 24 $149.95 x 2 = $299.90

I know others have mentioned lithium batteries. Specifically Lithium Iron Phosphate (LiFePO4). I recently purchased Li Time batteries. You can purchase a Li Time battery that will give you more useable power than two group 24 batteries (100Ah vs. 81Ah). And the current prices is $269.99 which is $30 less than the suggested retail price of Interstate lead acid batteries.

https://www.litime.com/products/liti...ifepo4-battery

Other things to consider if you purchase LiFePO4 batteries
1. They will typically last four to five times longer than lead acid
2. They are truly maintenance free.
3. You will need to invest in a lithium battery charger to get the fastest charging and the most complete charge cycle. Your old converter/charger will charge them up to about 90%.

Jim

[guest2]

Thank you all for the suggestions. Any ideas on what charger/converter for a 100 Ah Li battery?
I’m really a newbie to lithium.
Rich

[ncitro]

I've had good luck with both powermax and progressive industries.

Usually you want to charge below half of your amp hour capacity, but check with the specific battery you're looking at.

https://a.co/d/5RQol5J

[Sandridge4]

I installed a powermax based off the recommendation of others on this forum. I had a problem with the first one and when I contacted powermax they sent a new one the same day. They were great to work with. I would buy it again.

[guest2]

I would also go with two batteries vs. one. Also agree that lithium is definitely the way to go. We just finished a week in Quartzsite which was our first boondocking trip after converting to lithium. It was so nice not having to really worry about battery power. With our solar and new batteries we never needed the generator, watched tv, made coffee, ran a cpap all night and no generator! This is the brand we installed and couldn’t be happier. https://www.litime.com/collections/12v-batteries

Curious, how much solar and battery do you have?
Rich

[TucsonJim]

When replacing a converter, you want your current capacity to be similar to your current converter. If you go with too large a charger, you may have more amperage than your wiring can handle. If you go too small, it will take a long time to charge.

According to the GDRV parts look up page, your 2021 2600RB came equipped with a 55 amp combination distribution center/converter from WFCO. I believe you have 30 amp shore power. Most likely, this is a model WFCO 8955. But check your specific model. You may have a WFCO 8955-AD. If so, it's already set up to detect and charge lithium batteries! If not, you can purchase a brand new power center and converter for about $220 on Amazon.

https://a.co/d/3wJW0P3

Jim

[Scott'n'Wendy]

TucsonJim With the combination panels, can you disable the integrated one and add a stand alone?
If you can go stand alone....
I went with this Power max converter to replace my 9855wfco.
https://powermaxconverters.com/product/pm3-12v-series/
For a few reasons. First was for the reasons Jim stated. If you up the converter power, you need to start replacing charge wiring.
Second, was because you can if you wish switch the Powermax into manual mode and adjust the charge voltage to what you think is best.
Third, they can be paralleled. So when I decide to increase the battery capacity, I can just add another PM3-55 to the existing one instead of outright replacement.

[ncitro]

I agree with Scott. I would just disconnect the stock converter and install the new one in the front bay, then you just need to run 120v to the front bay to power it, and short 12v wires to the battery.

[Sandridge4]

Curious, how much solar and battery do you have?
Rich

We have 600 watts of solar and 200 amp hours of lithium batteries, am considering adding more to the battery bank.