mpp 6548 charging issues

[CMT36]

lve installed two mpp6548s, all is well. However I've noticed when attempting to charge my battery bank during the winter months. I've found that to make any real charging progress using my generator, I must set both machines to standby mode. Even then this takes 5 hours at 25.5 amps to even get 55volts of charge.
On my system 58.5 volts is considered full. Any help would be greatly appreciated.

 

[sunshine_eggo]

lve installed two mpp6548s, all is well. However I've noticed when attempting to charge my battery bank during the winter months. I've found that to make any real charging progress using my generator, I must set both machines to standby mode. Even then this takes 5 hours at 25.5 amps to even get 55volts of charge.
On my system 58.5 volts is considered full. Any help would be greatly appreciated.

Voltronics units are notorious for being intolerant of even slightly dirty generator power. That's why the Chargeverter was created.

You've likely found the second most effective solution (chargeverter being the first) - standby charging.

Some are able to get charge and pass-through by lowering the AC charge current and increasing it slowly until the unit balks, then back off. However, this is likely to take even longer to charge.

Have you confirmed you've set your AC charge current to maximum? Remember this is CHARGE current at battery voltage, not the current it draws from the generator.

 

[CMT36]

Thanks for such a prompt reply!
I will take a look at my charging perimeters and see if there is anything more I can do. mpp 6548s
Have a step by step guide, numbered 1 - 99. My guess would be to check the settings between 2 and 30.
Thanks again

 

[sunshine_eggo]

If you have:

https://www.mppsolar.com/manual/SPLIT%20PHASE%20LV/LV6548%20split%20phase%20manual-20210416.pdf

02 must be high enough to permit AC and PV charging current combined (default 60A, max 120A).
11 is maximum utility charging current (default 30A, max 120A)

Again, you'll still have to charge in standby, but you may be able to charge at a higher rate.

You will need to balance this value with your generator max power. Target charge power + load power = 70-80% of the max generator output.

 

[Quattrohead]

to even get 55volts of charge.
On my system 58.5 volts is considered full.

55v is very close to full, some would consider it fully charged. 58.5v is cooking them.

 

[sunshine_eggo]

55v is very close to full, some would consider it fully charged. 58.5v is cooking them.

@CMT36

This is a good point - definitely a high state of charge especially if this level is achieved at low current. 55V is 3.44V/cell. Some only charge to 55.2V or 3.45V/cell.

 

[CMT36]

If you have:

https://www.mppsolar.com/manual/SPLIT%20PHASE%20LV/LV6548%20split%20phase%20manual-20210416.pdf

02 must be high enough to permit AC and PV charging current combined (default 60A, max 120A).
11 is maximum utility charging current (default 30A, max 120A)

Again, you'll still have to charge in standby, but you may be able to charge at a higher rate.

You will need to balance this value with your generator max power. Target charge power + load power = 70-80% of the max generator output.

Thanks I'll check these perimeters first thing.

 

[CMT36]

@CMT36

This is a good point - definitely a high state of charge especially if this level is achieved at low current. 55V is 3.44V/cell. Some only charge to 55.2V or 3.45V/cell.

Sounds like I've got one more thing to add to my list. I've been charging these cells to 58.5 for 5 years now. Sadly, my battery bank came with zero information or support.