Charging cold EG4 PowerPro batteries with chargeverter

[hayduke]

I have a 6000XP and wall mount powerpro indoor battery at an off grid cabin in northern Minnesota that is occupied just intermittently in the winter and I recently purchased a chargeverter to help charge batteries as our PV array is no longer keeping up . I'm wondering how the chargeverter will work if I arrive to below freezing temperature batteries that need charging. I know LiFePO batteries need to be above freezing to accept a charge and my understanding is that in the normal operating mode the powerpro's have internal heaters that will kick on to warmup the battery before attempting to charge with PV via the 6000xp.

What will happen if I connect the chargeverter to cold batteries, is the system smart enough to use chargeverter power initially for internal heating and change over to charging when the batteries are warm? Would I need to change the PowerPro communication cables from the 6000xp to the chargeverter to enable this self heating? Would the situation be any different if I was to try to charge cold batteries using the generator input on the 6000xp with an appropriate 240V generator instead of via a chargeverter? Thanks for the help!

 

[EG4TechSolutionsTeam]

The battery is equipped with a heater that maintains the internal temperature at or above 32°F. When the battery SOC drops to 10%, the heater will turn off. If the internal temperature falls below 23°F, the battery will enter temperature protection mode and will recover once the internal temperature rises to 32°F or higher.

 

[hayduke]

@EG4TechSolutionsTeam thanks for the response. What should I do if I arrive to batteries that are at say 15F and at 9% SOC, can I fire up the chargeverter like normal? I'm not clear on if the built-in heaters can use the supplied chargeverter power to warm up the batteries and then transition to accepting a charge, or is it a chicken-and-egg problem where the heaters can't run without sufficient SOC which they can't get without being warm enough?

 

[EG4TechSolutionsTeam]

The BMS must report a temperature between 32°F and 113°F to allow charging.

 

[Recovering EE]

The BMS must report a temperature between 32°F and 113°F to allow charging.

View attachment 257906

Check post #3 again. I don't think you answered their question.

 

[wpns]

I do not believe that the batteries have a separate circuit to allow incoming power to run the heaters while still preventing incoming power from getting to the battery cells. That would make an interesting upgrade for the next generation battery though.

 

[hayduke]

The BMS must report a temperature between 32°F and 113°F to allow charging.

View attachment 257906

Thanks for weighing in again @EG4TechSolutionsTeam but this still isn't quite getting to the heart of my question. With batteries <32F and <10% SOC, can I safely plug in the chargeverter?

From what you've said, in those conditions it seems that the BMS will not allow charging. Can it use the chargeverter power to run the internal heater initially and then accept a charge once the batteries are warmed up?

 

[HRTKD]

Most BMS that have a heating option will work in your situation. Provide a charge and the heating circuit will fire up and begin warming the batteries. The BMS will not allow a charge to get through to the battery until the battery temperature has reached the proper threshold.

I can't say if EG4 follows this convention or not.

 

[Branch Ranch]

With batteries <32F and <10% SOC, can I safely plug in the chargeverter?

I have the exact same set up in my cabin in Montana. I rarely get there in the winter but would like to know the answer to this as well. I keep the entire system off and try to have battery around 50% for storage over winter.

 

[hayduke]

To followup on this, the chargeverter worked exactly as I had hoped. I arrived to dead batteries and 20F temps, fired up the generator and plugged in the chargeverter. Initially it automatically limited current to 4.5 amps and used the internal 200 watt heater in the powerpro to warm the batteries back up. After about an hour the min cell temp got above freezing and the chargeverter automatically kicked back up to my preset charging amps.

 

[dopeassjackson]

To followup on this, the chargeverter worked exactly as I had hoped. I arrived to dead batteries and 20F temps, fired up the generator and plugged in the chargeverter. Initially it automatically limited current to 4.5 amps and used the internal 200 watt heater in the powerpro to warm the batteries back up. After about an hour the min cell temp got above freezing and the chargeverter automatically kicked back up to my preset charging amps.

If you wanted to speed that time up or just keep them warmer a cheap electric heater by the batteries can do wonders.

Have you thought about just leaving the batteries hooked to the charge controller and turning any loads off? This works well for my FLA in snow country. In fact in 4yrs I only disconnected the batteries and CC once, to move the whole system. I always arrive to charged batteries.

 

[hayduke]

If you wanted to speed that time up or just keep them warmer a cheap electric heater by the batteries can do wonders.

Have you thought about just leaving the batteries hooked to the charge controller and turning any loads off? This works well for my FLA in snow country. In fact in 4yrs I only disconnected the batteries and CC once, to move the whole system. I always arrive to charged batteries.

I'd love to be able to turn off the inverter and have the batteries charge from the MPPT in the 6000xp but have not been able to get that to work reliably. Here's a separate thread I have going that talks about this issue: https://diysolarforum.com/threads/eg4-6000xp-pv-not-charging-with-eps-off.97242/

I want to keep some loads on so I can run starlink, cameras and a weather station but I've been able to move those all to 48V so I don't need the inverter idle consumption.