Balance issues new batteries. Chargeverter passthrough on open battery breaker?

[meltdowndave]

Just had new electrical service installed and finished wiring up my 18KPV and two PowerPro batteries. No PV yet attached.

Despite the battery voltages only being 5/100ths apart when first turned on, there seems to be an issue where a low voltage alarm kicks in @ 27% but at 45V. I'm pretty sure that I need to trickle charge each battery individually to top balance them.

My EG4 Chargeverter is connected to a Victron Lynx Distributor that is wired to battery #2 (slave). Batteries #1 and #2 are connected via EG4's parallel cables with battery #1 then being wired to the inverter.

I'm an admittedly lazy person and don't want to physically tear apart the covers on the EG4 conduit boxes and remove cables.

That being said, if I shut down the inverter can I simply open the breaker of the battery that I don't want to charge? If the breaker for battery #2 is open (the one connected to the Lynx/Chargeverter) will it still charge battery #1? Or, do I physically have to remove the cabling of the other battery and connect the charger directly to the battery that needs balanced?

 

[sunshine_eggo]

Despite the battery voltages only being 5/100ths apart when first turned on, there seems to be an issue where a low voltage alarm kicks in @ 27% but at 45V. I'm pretty sure that I need to trickle charge each battery individually to top balance them.

In the operating range even imbalanced cells are nearly identical.

However, cut off at 45V is an average of 2.8V/cell, which is at a VERY low SoC, <5%. This may also be an issue where the SoC is not correct until the battery has been cycled multiple times - very common especially with new batteries.

My EG4 Chargeverter is connected to a Victron Lynx Distributor that is wired to battery #2 (slave). Batteries #1 and #2 are connected via EG4's parallel cables with battery #1 then being wired to the inverter.

A picture or a diagram would help as this seems suboptimal or wrong.

I'm an admittedly lazy person and don't want to physically tear apart the covers on the EG4 conduit boxes and remove cables.

That being said, if I shut down the inverter can I simply open the breaker of the battery that I don't want to charge? If the breaker for battery #2 is open (the one connected to the Lynx/Chargeverter) will it still charge battery #1? Or, do I physically have to remove the cabling of the other battery and connect the charger directly to the battery that needs balanced?

You've established one battery may have balance issues.

What you haven't established is that the other battery doesn't have balance issues.

Super lazy mode: continue cycling it and see if the discrepancy resolves after a few cycles with charges to 56.8V

Lazy mode: simply float the entire bank at 55.2-56.8V for 24 hours and allow the batteries to balance as needed.

 

[meltdowndave]

In the operating range even imbalanced cells are nearly identical.

However, cut off at 45V is an average of 2.8V/cell, which is at a VERY low SoC, <5%. This may also be an issue where the SoC is not correct until the battery has been cycled multiple times - very common especially with new batteries.



A picture or a diagram would help as this seems suboptimal or wrong.



You've established one battery may have balance issues.

What you haven't established is that the other battery doesn't have balance issues.

Super lazy mode: continue cycling it and see if the discrepancy resolves after a few cycles with charges to 56.8V

Lazy mode: simply float the entire bank at 55.2-56.8V for 24 hours and allow the batteries to balance as needed.

Thanks.

My cabin is an hour and 45 minutes away.

It's currently "stuck" at 77% and 52.6V and won't charge further.

Neither will the batteries discharge.

Tech support said that one of the batteries likely has an alarm and I need to clear it with BMS Tools. He recommended that I trickle charge each battery at 10 amps with the Chargeverter. Once each is topped off then I should be able to bring the system back online.

I can only visit on weekends. So I need to a strategy in place and tools on hand when I get there, otherwise it has to wait another week.

 

[sunshine_eggo]

Thanks.

My cabin is an hour and 45 minutes away.

It's currently "stuck" at 77% and 52.6V and won't charge further.

Neither will the batteries discharge.

Tech support said that one of the batteries likely has an alarm and I need to clear it with BMS Tools. He recommended that I trickle charge each battery at 10 amps with the Chargeverter. Once each is topped off then I should be able to bring the system back online.

I can only visit on weekends. So I need to a strategy in place and tools on hand when I get there, otherwise it has to wait another week.

I feel your pain. My place is 3.5 hours away, but I get to watch/control it on VRM. I'd go batty otherwise.