I am an absolute novice eager to explore the basics of my own batteries and how to care/maintain them over time as they are so expensive.

I have 2 x Omnipower OPR240-12 AGM batteries that don't seem to hold their charge. During load shedding pulling 200w they hardly last for an hour or so in a 24v configuration.

After charging for a week or two they reflect a SOC of around 13,8v for a few days and then gradually decline to around 12,9v after two months, measuring with a multimeter.

I have now replaced them with 2 x 24v 50aH Lithium batteries which meet my needs and will expand over time.

Going back to the AGM's, I would like to "pay it forward" to an elderly couple I know, possibly with a cheap 12v inverter I already have if as I suspect the one battery is still fine.

I have just received a EBC-A20 Battery tester and would like to test these batteries using the tester to see what condition they are in. But I do not know where to start, have spent all morning watching a number of YT videos but they all seem to be 3.7v lithium related, also tried to Google as well but nothing either.

I would sincerely appreciate any help and guidance from forum members on the parameter settings as per the bottom 3 screen dumps below for (1) D-CC constant current discharge, (2) D-CP constant power discharge, (3) C-CV constant voltage charge.

Thanks in advance for any time spent answering me and guidance provided.

 

 

 

 

Edited May 1, 20233 yr by DenBeech

Charge full then

D-CC 20A volt cutoff 10.8v should last 20hr

 

6 hours ago, user19 said:

Charge full then

D-CC 20A volt cutoff 10.8v should last 20hr

 

Many thanks for your guidance as provided namely on the D-CC screen use "Test Value" = 20A, "Cut-off Volt" = 10.8V and "Max Time" = 20Hrs?

I will start the test after work today. Thanks again. 👍

Edited May 2, 20233 yr by DenBeech

6 hours ago, DenBeech said:

Many thanks for your guidance as provided namely on the D-CC screen use "Test Value" = 20A, "Cut-off Volt" = 10.8V and "Max Time" = 20Hrs?

I will start the test after work today. Thanks again. 👍

Max time leave as 0

4 hours ago, Chris_S said:

Max time leave as 0

Many thanks for the assistance, I will follow your advice.👍

Thanks to forum members for all the advice.

I have purchased two 24V 25aH each 8S2P lithium iron pouch batteries connected in parallel to give me a 24V 50aH capacity.

Using the above EBC-A20 charger to charge (C-CV mode) my batteries what would the following parameters be?

Test value |Voltage | Cutoff Current.

The batteries have been running perfectly since Oct 2022 but recently started giving me "wiring error" message on the inverter. So would like to charge them up (now 25.33v) to see if the error persists.

any advise on the settings or otherwise sincerely appreciated. TIA.