Adding an extra battery to the truck for electronics?

NO, it needs to have a proper way to charge it, otherwise it will never reach 100% charged.

 

That's what an isolator does.... When the truck is running, everything charges. When it's off the second battery circuit doesn't discharge the start batteries.

 

NO the isolator doesn't charge anything, the LiFePo battery needs to be charged with a different profile than does lead acid batteries. The isolator has a voltage drop and all it does is act like a check valve.

You need to either have a proper battery charger added into the system or change out the voltage regulator to something that has a LiFePo battery profile.

 

You are operating with outdated information.
Victron isolator drops the voltage by 0.1 volts at high load.
Modern 12 volt drop in replacement lithium batteries have a built in BMS.
Charge profile doesn't matter. They take in only the amps that are required by the battery.
Most have a 100 amp or 200 amp BMS. They will take every electron the alternator will put out, and when full, they don't take more.

So like I said,
Battery isolator https://www.amazon.com/VICTRON-Argofet-Battery-Isolator-Batteries/dp/B078RD87KC
battery https://www.amazon.com/Redodo-LiFeP...fix=100ah+lithium+chins,electronics,87&sr=1-2
really any chinese crap will work, but make sure it has a low temp charging cutout.

 

Not trying to argue with anyone but we tried all kinds of configurations with LiFePo batteries on my trucks having had good luck with putting a charger on them. We went through a few battle born batteries and talking to the guys over there, they do not recommend putting a lower (13.8 to 14.2 volt) on the battery to charge them. They said they need 14.6 to 14.8 volts to get them fully charges (14.4 is the lowest) and have the cells top balanced through the BMS. This also insures a longer life out of the battery. Sure you can charge them up with the truck system but then why not use a proper charge, get it up to 100% instead of 90% and it lasts longer.

The chargers for these batteries are not expensive, and they have the right profile for the LiFePo batteries, justas AGM batteries need a different profile for proper charging.

LiFePo batteries have pretty decent BMS but the purpose of the BMS is to limit the current in and out so to prevent runaway conditions that we all have seen. Some of the better chinese batteries (actually all the cells are going to be Chinese with Taiwanese material sourcing no matter who makes the battery) have heaters in them which turn on when it gets cold. A few we have tested here in the outside never hit the low temp limit to turn off because of the heater in the battery case.

I have a few trucks with the Maxwell starting systam, Chins batteries (three) for the house batteries and using Balmar 614 regulator which is programed for charging the LiFePo batteries with a 200 amp delco alternator. This works well, when the regulator was installed and programed, the batteries were always fully charged. The drivers love the system, one of them (against my wishes) does gaming on the weekend with a large gaming system.

 

If you really want to put your mind at ease.

 

As long as you have 4 brand new batteries in great condition. I fail to see why you need extra.

Or if accommodations can be made. 5 or 6.

Most of us get by with the standard 3 in the FL's.

 

I've mentioned in other threads that the International LTs with EPUs come with 8 deep cycles. It powers the fridge and espar for weekend, and the A/C in the summer for at least a 10 hour when the batteries are getting older. They've got 4 under the driver step, and an additional 4 in a saddle box between the rails behind the sleeper.

 

Do you have something in place of the Maxwell system when it goes out since they no longer make it?