FullRiver DC400-6 AGM batteries - Boondocking performance

[Gary.Jones]

I thought that I would provide an update and operational data on the new FullRiver AGM DC400-6 house batteries that I bought to replaced my tired 2019 Cornerstone OEM house battery bank this past summer. The OEM Relion batteries were no longer able to handle low, minimal house battery needs over night at the ENTEGRA@QUARTZSITE GATHERING each January e.g. refrigerator, AquaHot, resting Hopper-3 DVR, etc beyond about 3:00 am before the voltage would drop to 12.1 VDC and trigger the Automatic Generator Start (AGS) process for the Onan generator. So, it was time to replace the 4 house AGM batteries.

I shopped hard in May and June of 2021 trying to find the batteries that I wanted to buy (Lifeline 6 volt AGMs) however there was a 6 to 8 week backorder delay (optimistically) for the batteries I wanted that was produced by the pandemic-disrupted supply-chains. However, Dee and I were leaving early August for a three month tour of the west and upper far-west and I just could not wait for the batteries to become available. So, I did a lot of on-line research, called most of the major manufacturers, and many battery dealers. My research pointed me toward FullRiver DC400-6 AGM batteries which seemed to have good specs and a good reputation. The batteries were priced about $100 less than the Lifelines including no tax and free shipping at the time. Four batteries arrived on a wooden pallet via truck freight. I did the installation/swap of the batteries. (I will post another thread).

I have now been on the road for 2.5 months and have had time to use the FullRivers for occasional boondocking and they have performed well. Generally speaking, 2 hours of running the Onan generator in the evening, led to a charge voltage of 14.2 volts. After a time to settle, the batteries were at 12.7 or 12.6 volts by the time we would get to bed or hit “quiet time” (10:00 pm) when all generators had to be turned off. Getting up at 7:00 am, and with all standard electrical loads “on” that would be left “on” even with commercial power (residential refrigerator, AquaHot diesel burner, electronics, lights out, etc. etc.), the battery voltage was 12.4 volts in the morning So, a loss of .2 to .3 volts overnight (12.6 to 12.4 volts) over a span of 9 hours. I consider that excellent and I have been very pleased by that performance. Two more hours run time as soon as we wake up, and the Magnums would pump ~ 100 amps into each battery bank in Bulk charging mode for maybe 20 minutes before dropping to ~80, then 60, then 40, then 20 amps through the two hour re-charge Onan run. In the evening, we would repeat this process. We also routinely run the genny at lunch or dinner if we are using the induction cooktop or the microwave, but only during this high amperage device usage.

So far, so good! There were no incidents of the AGS kicking the Onan to start which is set at 12.1 volts. I never got close to 12.1 volts overnight. Impressed so far. I have no connection to the FullRiver Company....

Gary

[757driver]

Gary,

Great report. I have also heard good things about Fullriver batteries. Glad they are working well.

[twinboat]

That's a great result.

If the original batteries were getting weak, wouldn't it had made sense to set the AGS down to 11.8 or even 12.0 volts, just to get some more life out of them before junking them ?

12.2 volts is 50% SOC and you could have easily used another 20% to 30% of the remaining capacity. You knew the batteries were on the way out anyway.

You may have gotten another season out of them.

[Gary.Jones]

My experience with both my 2015 Anthem and now my 2019 Cornerstone, was that if I was still using the OEM batteries in the coach, 11.8 or 11.7 VDC was so low that the batteries did not have enough "juice" in them to successfully roll the Onan 12KW genny..... too little too late. So, with my OEMs installed, I could get a more reliable start of the Onan at 12.1, which was needed just about every night.

Just what I have found works best (these batteries may not need set that high but are nowhere close to either start threshold.

Gary

[dave&ginny]

Gary I'm glad they're working as planed. I bought mine a few years back and they've held up well.

[seeg]

I replaced my boat house bank with FullRiver group 31’s. Slightly larger footprint but the same results as you received. We were always on the hook after we left our slip and running the genset a couple of times a day was sufficient to keep them topped off. I won’t hesitate to replace my house batteries with FullRiver when the time comes but don’t look forward to man handling the 6 volt batteries. Changing out the group 31’s , in and out of the bilge, was pretty much a full day job for Pam and I. And, I was much younger.

[Winemaker2]

See
You are lucky.... my 3 boat battys are 8Ds!
It takes 4 to get them out of the engine rm.
My plan is to replace each with a pair of GP31s.

Sent from my SM-T387V using iRV2 - RV Forum mobile app