Getting AGM batteries to equal charg

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I have four Kilovault 180Ah AGM 12v batteries - two strings of 2 for 24 volts. I've been running them for about 9 months. Decided it might be good to add a battery balancer, so ordered the KiloVault BE24 balancer - one unit. Instructions come with the caution to charge the batteries to the same voltage. What is the best way to do that?

Is it proper to check voltage for each battery with a volt meter on the individual battery terminals while they are all connected in the bank?

Also, how equal is "equal"? What is the allowable deviation?
Thanks

 

[sunshine_eggo]

Take one of the strings out, parallel them as 12V, charge to full.

Repeat for other string.

 

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My solar charger is a Classic 150 - I believe it can charge at 12 volts by changing the parameters. My inverter can only take in 24 volts, so I would have to take that off line. Since I am living off grid, that would be somewhat problematic unless I run the generator and isolate the battery bank from the inverter.

The question then is - how long would it take to equalize the two strings with 2500 watts of solar on a sunny day?

Thanks

 

[sunshine_eggo]

2500W @ 12V is 208A. Classic is limited to 96A on 12V

Assuming dead empty batteries and full power solar, 4 hours. Realistically, 1-2hr AFTER a full charge to 24V. You'd basically just be running absorption on them.

You thinking?

1. Fully charge 24V system.
2. Pull out 1 string, parallel as 12V
3. Disconnect panels and battery from Classic.
4. Connect Classic to 12V and panels
5. Change charge parameters (14.X absorption, 7.2A tail current, 13.X float).
6. Charge until float.
7. Restore system to original configuration.
8. Install balancer on equalized string.
9. Repeat 1-7 for the other string tomorrow.

If so, that's what I'd do.