Starting 5.5 Onan Generator with 2 BB 100 Ah batteries

[BackCountry]

I am upgrading my batteries and converter this spring to 2 heated Battle Born 100 Ah Batteries and replacing my Converter with a Progressive Dynamics 60 amp LiFePO4 Converter. Battle Born says two 100 Ah batteries will "almost always start your onboard generator". What are peoples experience with duel BB 100 Ah batteries starting 5.5 Onan generator?

[FT4NOW]

I had a single 100AH lithium in my 399 and it always started my generator. I imagine with 2 batteries, you are in a better position so shouldn't be any issues unless of course you run them both completely dead. I also had a Victron BMV-712 to monitor the battery to ensure I started the generator before it was to late.

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[BackCountry]

Thanks for the input. 200 Ah is far more than I would ever need for running everything especially with solar and generator. Never had and issue with my two 88 Ah Interstate batteries ever coming close to 50% drain even on the coldest nights. I have a Renogy Battery Monitoring System so I can monitor my batteries and set an alarm at a certain Ah drain so I can start the Generator if necessary. Never had that happen. Wonder what level I should set that at with LiFePO4 batteries - 30% or 60 Ah remaining? At what point do LiFePO4 batteries start to drop amperage output? On my Milwaukee 18v tools it is typically full power until they stop.

[Gainestr]

Thanks for the input. 200 Ah is far more than I would ever need for running everything especially with solar and generator. Never had and issue with my two 88 Ah Interstate batteries ever coming close to 50% drain even on the coldest nights. I have a Renogy Battery Monitoring System so I can monitor my batteries and set an alarm at a certain Ah drain so I can start the Generator if necessary. Never had that happen. Wonder what level I should set that at with LiFePO4 batteries - 30% or 60 Ah remaining? At what point do LiFePO4 batteries start to drop amperage output? On my Milwaukee 18v tools it is typically full power until they stop.

You could technically run them down until they stop just like your Milwaukee. The built in BMS would stop them from completely draining but I would use your Renogy Battery Monitor and figure out where the knee is on your battery and stop it there(12.5V-12.6V). I personally run my down to 12V before I charge. You could safely run them down to 15% without worries and just call it a day and you will be just fine. Those LiFePO4 batteries will last probably a good 10 years even when ran fully down. Even then they will still retain 80% of their power so use them! In 10 years you can worry about the next battery technology and ask this question again.