100 Percent SOC

[Zbrixy]

I just recently got another battery backup for my system and when i got it hooked up,  At the time i was at 97 percent SOC.  When i hooked it up  it was reading 100 percent SOC.  And now when it charges it gets to the 100 percent and keeps going in the plus side and was wondering what i need to do to get it so it knows when the batterys are indeed full charge.  The first day of the new batterys it went as high as 42 on the plus side and still wanted to charge but couldnt because nightfall came. 

The original battery bank was 800amp hrs and i added an additional 800 amp hrs to the battery bank giving me a total of 1600amp hr.  Its a 48 volt system and has two charge controllers and two magnum inverters with 24 panels 230 watts each.  The system is really able to charge during the day and isnt uncommon for the DCamps hrs to hit 100.

Any input would be nice as to fix the problem with the SOC being at a 100 and it still wants to charge. 

[Robin]

A couple of questions.
1. how old are the original batteries?
I am not sure what you are using to measure the 97% and 100%?
What does 42 mean?
What do you mean by it keeps going in the plus side?
Even with the batteries at 100%, it takes some small amount of current to keep them at the bulk or absorption voltage. We need more information. What is the charge controller state? Bulk, absorb, float?
What make and model of controllers are you using? They may not be playing well together?

[Zbrixy]

The original batterys are only 3 months old

Using my magnum RTR

Say the RTR is at 90 percent SOC it is missing on the BMK screen  -160 Amphr. Now when it says 100 Percent SOC it cont. to charge and goes positive and i get a plus number.

Ive seen the system at 100 Percent SOC and the controllers are still on bulk charging

Charge controllers r both classic 150s

[Robin]

We install a lot of Magnum BMK's although I have no actual experience with them. If both charge controllers are still in Bulk when the BMK reads 100%, then the BMK is not set to the same standard as the controllers. The controllers are going to charge until the settings have been reached. The BMK is going to say 100% when its settings have been reached. Look to adjust the Magnum BMK setting higher so it won't prematurely say the batteries are full.
We have a very simple and cheap monitor that can be used as a good sanity check. It is common to use a monitor such as the BMK as well as our MNBCM on the same system. Our monitor is voltage based and has no adjustments. You would want to read our monitor when the batteries are at rest (not under charge).