My AMGs have died >:( , my fault, but they're dead. Reading about 8V and charger (XC2000) wont start. I'm considering LiFePo batts but I'm concerned that they can't start the gen due to lower cranking amps available from Li batts (schematic shows gen starter is hooked to house batts). Anyone here have any concerns or advice on this? BTW I don't currently have solar and I'm pretty much tapped out on $$$ due to other repairs I'm making so please don't suggest ripping everything out and starting over.
Regards
I did this swap about two years ago. LiFeP04 batteries are not a drop in replacement (yet) and require a bit of research and planning to get right.
However, the good news is that my 3x 100AH Chins brand (Amazon) start my 10KW Powertech generator just fine. IIRC, the batteries want up to 100 amps of draw each, but provide a peak of 300A each for short intervals.
I was planning to use the extra space for a small AGM starting battery, but it turned out I didn't need it.
Why not try a charger with a desulfanator function and try and bring the batteries back,what exactly did you do or did'nt do,why
not just get less expensive batteries and care for them properly.
I agree. Use a "stupid"/automotive charger, jump from another vehicle, or even coach's alternator to bring the house bank back up to voltage where your on-board will charge them. When fully charged, use the "stupid"/automotive charger to bring voltage up to high 15 VDC.
Be sure to disconnect all coach 12 VDC loads when you do this last part as some PC boards may be sensitive to high voltage.
THEN evaluate the batteries.
AGM's work great when properly charged and maintained.
Stupid charger for sure. Also the generator takes very little to start at a lower required voltage. I started my generator for a year with a junk old optima battery.
I was stupid and let them sit unattended. Even with the DC disconnect there must have been some drain on them. This is a new coach for me so it could also be that they were not in good shape to begin with. From now on I'm going to disconnect the batts entirely when the coach is in storage regardless of the solution I come up with. Can you recommend a BC brand with desulfanator?
So just start the engine and enable the boost?
Shouldn't even need to do that, as the alternator automatically charges both chassis and house battery banks.
Turning on boost will speed up charge of the house batteries (by taking a lot of amp VERY QUICKLY) from the chassis bank. May cause voltage spikes with the chassis battery at full charge and house battery deeply discharged. I would not do it that way.
John, if you replace your house AGMs with Lithium you won't have any trouble starting your generator. If you did, you could hit the boost switch and "add" your bank of start batteries to the party. If that doesn't spin your generator like a top, you have other problems.
Meanwhile I would definitely try to revive your coach batteries as recommended by reply 2 & 3 et al. That should keep you going without shelling out any money.
Personally, I feel the price of lithium batteries has come down to the point that it doesn't make much sense to purchase new AGMs. They are half the weight, almost double the useable capacity, recharge to 100% much faster, and provide superior voltage stability under load. A Victron Orion B2B will protect your alternator and a Victron shunt will give you great info on where your 12 volts disappear to and how quickly they can be replaced. You don't need solar to reap those benefits.