[Richard]

Read my three edition series in Bus Conversion Magazine for step by step instructions on how to do this safely and correctly. Lots of misinformation out there so don’t wing it. There is way more to it than just changing batteries. You want to wind up with no possibility of the lead acid starting batteries in your engine and generator ever being able to be directly connected to your house lithium battery bank. And you want the new Li house bank to fully charge from shore power, the generator, the engine alternator and optionally solar with no user intervention. It can be done if you are careful and don’t take any short cuts.

Jerry

[BW]

Hmmmmmmm. Not very helpful unless you want to subscribe to BCM.

[Mike, 92 Country Coach]

I have a question about how to handle the 12V starting batteries and 24V LiPoFe setup.

I am no stranger to LiFePo, I ran a selfmade 1000ah bank for 10 years.

I am a stranger to the 12/24V setups in the Prevost world.

It makes perfect sense to me to install 24 V LiPoFe to minimize balance problems, utilize the monster 24V 50DN. I understand adding DC to DC converter(s) to provide 12V to the house. This would pretty much take the Vanners out of the equation for the house.

But how do you handle the 12V starting batteries that are wired 2S/2P. Would you still use the Vanner to keep them equalized? Would you simply wire them 2s2P to the alternator and not worry about it? Is there another solution that I am missing.

Thank you for your input.

[Jon]

I’m not familiar with Marathon, but my Li and chassis batteries can never merge.

I have a single 50DN, but power to the batteries is via an isolator so the two battery banks see the same charging current (27.7) but the Li batteries are all 24V with Victron 24 to12 converters.

[DON]

Thanks Jon, I read your article on the conversion, but you did not mention anything that you did in regards to the house batts. Now, I understand better that you mention the big diode isolator. I did not have luck with the isolator approach on a previous LiPoFe setup because of the much lower internal resistance of the LiPoFe’s

I’ll keep digging. I was looking of previous insight before it just start tracing wires to figure out how it is in the unmolested state.

[Art]

Just to be clear, I went with all 24V Li batteries because the original ones installed did not like the parallel / series cabling and eventually they shut down because they weren’t charging properly. Relion’s literature said the parallel / series connections were OK, but it wasn’t and to their credit they stood behind the replacement.

I’m in my fifth year with the switch to Li for the house and if the charts are correct I have about another 14 years to go before they need replacement.

[Mike, 92 Country Coach]

Hey all,

Any Marathon XL converter owners out there performed the lithium upgrade? Looking to upgrade this year during the summer just want to get some insight on the in’s and out’s and things I should look for. Also I have Xantrex SW 3024 inverters which shouldn’t be an issue from what I have read so far.

If you keep it simple meaning just replacing the batteries, I will assume you currently have AGM? If so, the charge profile is very close to AGM, it is an easy swap. If you have other things you want to do like changing the battery voltages, swapping out the inverter, adding Solar etc, there are more things to consider.

[Bill]

Thanks everyone for the response…like you mentioned Mike I do want to keep it simple…and yes I do have the LIFELINE 12V AGMs (6) 210ah each. I was looking to keep the 12/24V configuration keeping the bank at 6 batteries (if possible). I do know that shore power and generator operation does not effect the engine battery bank. They are only charged by the 50DN, but the alternator does charge the house battery bank.

Jerry I will read your series today for more insight.