[MRRiley]

If you're still around, I too would love to hear how the install and tech has aged. Thanks!

[folivier]

I just removed 3 8D gel batteries from my Foretravel and installed 3 100amphour BattleBorn LiFePO4 batteries. Same advantages, removed 450# and replaced with 100#, faster charging, no slow absorption charging, very little voltage sag at high amp draws.
And these are manufactured in a nice clean package with built-in BMS for over/under discharge, over/under voltage, and temperature protection. And a 10 year warranty!
The recommended charge voltages are 14.4 v, absorb for 30 minutes/100 amps (1.5 hours on mine) and float at 13.4 v. I think this is a bit different than the Balqon Winston cells I sold to Richard. Not sure if the individual cell chemistry is different or they just have more empirical data.
When researching this project I narrowed it down to these and LifeBlue batteries. BB had a $100 off Black Friday sale so I bought them then. Trojan is introducing their line of similar batteries so they're worth a look.
I briefly looked at building a pack with Winston or Calb cells but the price difference with a BMS was about the same as these. And only a 2 year factory warranty, from the China manufacturer. BattleBorns are put together in Nevada and they warranty them there.
My Prosine 2500 watt inverter charges these to specs, I also have 400 watts solar with a Victron Smart controller which also charges to specs. I added a cut-off switch to the isolator to protect the alternator and belts from overheating.
But you have to ask yourself if this is what you really want, if you'll do a lot of boon docking then they have great advantages. We'll be doing a lot on our Alaska trip this summer. They are not cheap but should outlast agms, gels, or lead acids which will bring the overall cost down a lot.

[Richard]

If you're still around, I too would love to hear how the install and tech has aged. Thanks!

I'm not sure if you were asking Forrest or me.

I have nothing to report. They are still working just fine for my use. I did notice some drop, unquantified, in capacity. However, with the charging info that has been published in the last two years, I realized that I was undercharging the bank. That is not a problem for the batteries, but it explains the loss in capacity. I have slightly adjusted my charging scheme, but I have not done any dry camping since the adjustments.

I did take all the connections loose, clean them, and coat with antioxidant. That is the extent of the maintenance in four years.

[edkunkel]

When it comes to integrated batteries, like the Battleborns:  just how many of those batteries fit in the space of six 8d batteries, like the Lifeline lead acid?

Battleborn Dimensions are (L x W x H): 12.75 x 6.875 x 9  

Eric

[folivier]

Eric, you could possibly squeeze three 100 amp BBs in the space of one 8D but they would probably be sitting on top of the angle iron rack. But since these do not require any maintenance you could remove the rack and set the BBs on a shelf (they only weigh 33# each). So each 8D has ~ 250 amps (but only 50% are usable) so you could conceivably almost double your capacity. According to BB it is ok to draw their batteries down to 0%. I don't plan to go below 20% SOC on mine.
You'd have to measure carefully to fit 3 BBs in the space of one 8D and the heavy cables would be a tight fit. Or you could attach each battery to a heavy bus bar.
But the first thing to do is an energy audit to see how many amp hours you actually need. The big refrigerator would require at least 1 BB just to run it. Other things like the microwave, 120Vac water pump, etc. need to be added up over a 24 hour period. Then how will you recharge them? Generator? Solar? Engine alternator?

[pairodice]

Richard, you said “What I have learned in playing with this would have gone a long way to maximizing the AGM batteries I did have”. Would you mind sharing that info with us AGM users please? I would love to NOT murder another set of new batteries! I cannot attend the rally due to work demands...

[Richard]

Sure. The basic premise is that every excursion below 50% capacity, and every overcharge takes irreplaceable life out of the battery. This applies to standard lead acid and AGM battery technology. Lithium technology can be taken much deeper in the SOC without harm.

First, NEVER let the batteries get below 50% charge. You will have to look up what voltage that is for your specific brand of AGM. Set the Low Voltage Cutoff LBCO on your inverter to that voltage. Better yet use an inverter charger that calculates State of Charge (SOC) or install a meter that displays SOC. One thing to be totally aware of is that the Aquahot pulls directly from the batteries, and not through the inverter. So dry camping in cold weather has the potential for takeing the house batteries to a very low SOC.

Second, Use the specific charge profile recommended by your battery manufacturer. Adjust the charger outputs to match what is recommended by the supplier.

Third, be very aware that merging the batteries while driving has two downsides. It can put a strain on the alternator depending on the discharge state of the house batteries, and the alternator does not have the same smarts as the charger when it comes to charging profile. I know you disagree, but when the batteries are merged while parked, the chassis batteries are subjected to the charging profile setup for the house batteries. The AGMs and normal lead acid batteries take a slightly different charge profile. You are likely to boil your chassis batteries if you keep them merged while plugged in. In my opinion, if you feel like you need to charge the house batteries while driving, crank the generator. Yeah, yeah, I know then why did almost all manufacturers install the capability to charge the house batteries from the alternator. Just because you can doesn't mean you should. The original question was "how do I keep from murdering my batteries?" In my opinion, given the replacement costs of an alternator, you can buy a few gallons of fuel for the gennie.

This may sound fiddly, but once you set the systems up with the proper parameters, and you adhere to the practices, very little attention is required for the batteries.

@"folivier" may have some additional input

[folivier]

Only input is on my lithium install in the FT I added a cutoff switch at the isolator so that I can decide when the alternator charges the lithiums. This setup allows the alternator to only charge the 3 redtop Optimas unless I throw the switch.

[pairodice]

Thanks for the detailed explanation (which I will probably have to re-read 5 times to understand).
We just put in 6 (six) new AGM batteries that came from O’Reilly’s so not sure the brand but will do a search and see what they recommend for SOC. We have 4 8D AGM Deep Cycle batteries for the house (because we don’t boondock very often and for only one or two nights) and 2 8D Deep Cylcle AGM batteries for the engine. Not what I wanted at all but what the mechanics put in. So I can buy two more 8D starting batteries if that is better. I completely agree with you about not merging the batteries if using Deep Cycle and non-Deep Cycle (regular?) starting batteries. Would using all AGM Deep Cycles make a difference in what you stated earlier?
What meter can I add to show the SOC? I currently have a Freedom 25 (old) Inverter/Charger that seems to be working OK (although it does make me wonder whether the readings are accurate).

[Richard]

If the coach and the chassis batteries are the same type, then no issues with merging them and letting the charger do it's thing on all of them. If you do that you still have the possibility of leaving yourself stranded.

Reread the post. The charging profile, specifically the voltages for bulk, absorb, and float is what you are looking for from the manufacturer. SOC for any lead acid system, including AGM, should not be taken below 50 to maximize battery life.

People use AGMs for start batteries. It works, but standard lead acid batteries work slightly better. If I had your setup, I would move the AGM's currently in the chassis to the house, and replace the chassis batts with standard lead acid starting batteries.

Did you ever figure out why your batteries died at Tom's. You posted about the problems, and then crickets on the resolution.