Best way to work on batteries?

[jfharper]

I'm planning to dial in some balancing on my server rack bank, and from what I read need to disconnect a battery and charge it full, then connect it again when the others are full so I get closer to 100% balancing starting point. I'm trying to brainstorm the best way to work on the battery, meaning, when to disconnect it. My AIO's do NOT have any AC IN connected, I use generator lockouts for grid switching when needed. Here are some ideas:

1. Wait till solar is fully going, turn off breakers in the house/well so no load will exceed the solar coming it, turn off inverter to battery breakers, turn off all battery breakers, then disconnect battery in question, then turn ON inverter battery breakers then each individual battery breaker then house/well breakers can be turned on. BUT, if the inverters are actively charging the batteries is is BAD to disconnect the inverter battery breaker when 50amps is going thru it?
2. Do it when there is no solar (night), shut everything down, disconnect battery in question, get everything back up and running, fully charge battery in question, but then how/when to reconnect fully charge battery to others when they are 100%?
3. I do a switch to grid at some point, shut things down, get the battery disconnected, etc. BUT this is similar to #1.
4. Is there some way to work on a battery while it is still connected to everything safely, meaning not disconnecting/connecting it live?

 

[timselectric]

Assuming that the batteries are in parallel.
All that you need to do is charge to full, and float for a while.
Also Assuming that you have charging settings high enough to balance your batteries.
No need to disconnect anything. This can be done as a complete system.
Switch the loads to grid, so that all solar production will go to charging, for the day.

 

[timselectric]

What are your charge voltage settings for bulk and float?
The cells need to get above 3.45v per cell.

 

[zanydroid]

Would help to know the model of AIO

1. Wait till solar is fully going, turn off breakers in the house/well so no load will exceed the solar coming it, turn off inverter to battery breakers, turn off all battery breakers, then disconnect battery in question, then turn ON inverter battery breakers then each individual battery breaker then house/well breakers can be turned on. BUT, if the inverters are actively charging the batteries is is BAD to disconnect the inverter battery breaker when 50amps is going thru it?

Disconnecting under load is generally bad, but is there no graceful shutdown available by sending the appropriate setting to the inverter?

1. Do it when there is no solar (night), shut everything down, disconnect battery in question, get everything back up and running, fully charge battery in question, but then how/when to reconnect fully charge battery to others when they are 100%?

Why do you need to wait for "no sun"? You control the means of production/can make your own night by flipping your solar string isolators, which are required by code anyway.

You can also consider patching in the AC-IN to the AIO so that you can balance overnight instead of just when solar is available. Not sure this is worth the effort.

 

[jfharper]

Would help to know the model of AIO

Disconnecting under load is generally bad, but is there no graceful shutdown available by sending the appropriate setting to the inverter?

Why do you need to wait for "no sun"? You control the means of production/can make your own night by flipping your solar string isolators, which are required by code anyway.

You can also consider patching in the AC-IN to the AIO so that you can balance overnight instead of just when solar is available. Not sure this is worth the effort.

EG4 6500ex

 

[Bananaman321]

I'm planning to dial in some balancing on my server rack bank, and from what I read need to disconnect a battery and charge it full, then connect it again when the others are full so I get closer to 100% balancing starting point. I'm trying to brainstorm the best way to work on the battery, meaning, when to disconnect it. My AIO's do NOT have any AC IN connected, I use generator lockouts for grid switching when needed. Here are some ideas:

1. Wait till solar is fully going, turn off breakers in the house/well so no load will exceed the solar coming it, turn off inverter to battery breakers, turn off all battery breakers, then disconnect battery in question, then turn ON inverter battery breakers then each individual battery breaker then house/well breakers can be turned on. BUT, if the inverters are actively charging the batteries is is BAD to disconnect the inverter battery breaker when 50amps is going thru it?
2. Do it when there is no solar (night), shut everything down, disconnect battery in question, get everything back up and running, fully charge battery in question, but then how/when to reconnect fully charge battery to others when they are 100%?
3. I do a switch to grid at some point, shut things down, get the battery disconnected, etc. BUT this is similar to #1.
4. Is there some way to work on a battery while it is still connected to everything safely, meaning not disconnecting/connecting it live?

 

[jfharper]

What are your charge voltage settings for bulk and float?
The cells need to get above 3.45v per cell.

I still have 2 inverters setup in closed loop, eg4 mode, and the other 2 inverters are open loop set to USE, bulk is 55.2V and float 54V.

The 2 in closed loop are about to be set to USE and open loop and I am going to try to run wombatt for monitoring

 

[timselectric]

The 2 in closed loop are about to be set to USE and open loop

Do this and set bulk to 56v and float to 55.5v
And leave it like this for the whole day, with no loads.
Do it on a sunny day.

 

[Bananaman321]

Why are my EG4 batteries charging/discharging at different rates?

Hi folks, My two EG4 batteries are often way out of sync in terms of charge. Does anyone know why? Example: Right now, battery 1 is 76% full, while battery 2 is 85% full. If battery 1 gets too low, it will trip the inverter into grid-bypass mode, even when Battery 2 has plenty of power...

diysolarforum.com