Jump-starting Engine AGM with LFP house bank?

[KeepInTune]

Hey folks,
My boat is now wired up with a simple Blue Sea Systems switch where I can "jump" (combine) my Engine AGM from my 4 x 100ah house AGMs if ever my starter batt needs a jump.

I'm curious, if/when I switch my house AGM bank over to LFP's what are any concerning or potential issues of jumping a starter AGM with a house LFP bank? Assumed, any of jump connection would only be combined for a brief duration of time (~30 seconds) in order to start the engine.

Any thoughts on this?

Thanks for your consideration.

[Rohan]

That's not really "jump starting" but that's semantics, I get what you mean.

I also have mixed AGM starter with a LiFePO4 house bank.

If you combine your AGMs + LiFePO4 you are fine for a short time to start the engine. If you keep them combined then slowly the AGM will leech power from the LiFePO4 batteries, so don't do that for long periods of time.

BTW, if you have mixed sets like that, make sure you know where your alternator/solar/battery charger is charging, and that they are OK for LiFePO4 if that is what they are charging.

One solution is to install a DC - DC converter between them, then you can do it without any negative results, but that's extra wiring.

Personally, since my alternator is only good to charge the AGM battery, I simply flip from one bank to another depending on whether I'm motoring or anchored and wouldn't combine them unless I really desperately needed both banks to start the engine.