M643 charging new LifePO4 bank

[more]

Originally Posted by CharlieJ

A stock alternator, no matter how it is driven, will probably not survive charging an LFP battery/bank unless its output is derated so that the alternator temperature is < 100C or the max. temperature spec provided by the alternator manufacturer.
Here is a demo on how to fail an alternator:

for reasone in video in EU we have court, warranty fake advertise,
if alternator is 100A 125°C he must work and have inside protection inside,outside who care. i charge my 470 AH battery bank with new stock alternator pay before 4 year under 80$ every year working is 600 hour.
life winston baterry bank 200ah dont have bms , aded eva al case lithium have BMS.
on winston BMS i install for safety reson only 6A balancer

[skipperpete]

So here are the possibilities
1. My understanding was that the 14amp generator mounted alternator and it’s regulator were the subject of discussion ..... because the little alternator provides DC power to the AVR board which controls the AC generator field magnetism and hence the output.
based on this I then assumed that the OP was concerned that the AC generator ( M643) was somehow “trying too hard” to supply AC to the 4 battery chargers that are now charging the LifePo4 batteries in the new house bank and demanding excessive output from the little belt driven alternator to maintain field strength.
2. He meant the AVR burnt out and he’s springing the $900 for a new AVR..... AND a new AC live end for the genset... possible but very expensive.
3. He in fact really did mean the alternator on his main propulsion engine and its regulator and I misunderstood the thread from the very start.

[SV__Grace]

Originally Posted by wholybee

As for the question of if you are overloading your generator. You have 4 AC chargers, 120A, 50A, 50A, and 60A. That totals 280A. 280A x 14.6V = 4088W. Assuming 80% efficiency, 5110W. That *IS* overloading the generator. And the efficiency might be lower or higher, I'm not sure. You are working that generator very hard in any case. I would run it with just the 120A and 60A chargers, or upgrade to a larger generator.

+1 on this. My genset is 5.5kw and the experts told me not to run it past 80% or 4.5kw. My charging system can generate 300 12v amps into the batteries but that overloads the generator so the charge settings are throttled back to 200 amps max output, which shows up as 3.5kw on my monitor. Still, I'm able to fully charge my 1200ah battery bank in 4 hours from 20% where it would take 8 or more hours with the previous AGMs. I love that I don't HAVE to charge to 100% and never do so using my generator anymore- usually just run for a couple of hours then shut it off.

Also, changing from AGM to lithium batteries means that the generator is running all out for most of the charging cycle instead of the maddening Bulk/Absorption/Float for the AGM/LA batteries. A diesel engine can handle loads, even prefers to be loaded, but running at max for too long is pushing it IMHO.

[skipperpete]

Another interesting possibility is that IF the NL643 has no dedicated 12v battery and is deriving its 12vDC supply from the 1600AH LifePO4 battery bank then there will be a potential problem with the tiny alternator and its regulator effectively trying to charge that main bank