2004 Cat C7 Charging LifePo4 battery bank

Is your alternator air or oil cooled?

6?" or 8?/¹?" alternators can sustain 100% load.
Google DELCO, MOTOROLA, LEECE NEVILLE IMAGES and state which one you have.

I think CA is referring to the designation of amp-hours, not amps. Running ACs with 12v is going to require some big cabling. I think I'd prefer doing that with the 48v side.

CA Traveler wrote:
Not an expert but there have been prior posts that typically alternators will not sustian their maximum ratings without damage which is basically what you want with that amount of Ah.

But not sure what you mean by 1200A - Are you planning for 1200 Ah?

Suggest you get the model number and contact the mfg.

Well, by 1200 amps I meant 1200 usable amps. 6 280 amps batteries. 15kw in the 12v system. I also have 28kw in a 48V system to run all the 110-220 with a split phase.
This 12v battery bank will be for storing the solar and running the 12V side of the house. If needed, I can run 110V through the inverter (which I might be upgrading to a low frequency inverter so I can run ACs with the 12v batteries).
I have a 6kw inverter generator that I can use to recharge both banks at a 90% efficiency, if I ever need it, wich I don{t believe I ever will.
I am getting rid of my diesel generator. I am done with the smell, noise, maintenance and ineficiency. With what I get from selling the generators I can do all of this and more.
Now I have to find a way to control the flow from the alternator or install a timer on the batteries so the charge intermitently.

Not an expert but there have been prior posts that typically alternators will not sustian their maximum ratings without damage which is basically what you want with that amount of Ah.

But not sure what you mean by 1200A - Are you planning for 1200 Ah?

Suggest you get the model number and contact the mfg.

The charging rate will likely be determined by the size of the charging wire. Congrats on the 1200ah.

Running any vehicle alternator at max or near max for long periods won’t work IMO. Weren’t built for that level of service.

Matt_Colie wrote:
Map40,

I wish I could help more, but I am currently still in the research phase for a client. There are available DC-DC chargers that both create the correct final voltage for charging LiFePo4 batteries and limit the charge current drawn from the source. It is a single unit. There also should be a BMS Battery Management System with the Li unit to keep it from hurting itself or others. As said, this is a study in process on my part.

Matt

Thanks for the reply Matt. I got that part covered. The batteries are managed by their own BMS which can charge them dirvectly from the alternator feed. All of that works and so far I have 340 amps installed and they work great. My concern is: Will the alternator take the workload? The old Lead acid setup was 300 amps to recharge in the worst case, but when you talk about 1200 amps, the alternator will NEVER rest. Wil it last?

Map40,

I wish I could help more, but I am currently still in the research phase for a client. There are available DC-DC chargers that both create the correct final voltage for charging LiFePo4 batteries and limit the charge current drawn from the source. It is a single unit. There also should be a BMS Battery Management System with the Li unit to keep it from hurting itself or others. As said, this is a study in process on my part.

Matt