I am trying to find a battery tester to check SLA 6v/12v batteries that are found in UPS / emergency lighting etc.
I see there are some $300-500 units but that is not budget 
Looking for info like
Voltage
Current capacity left
Internal resistance
???
I have a lot of equipment with SLA’s to pm at work and if some are good I can either leave them in service, let people use them for home use (kayak fish finder comes to mind) then only need to replace the ones that need to be replaced.
I have googled some but was wondering if there are other units I should look for besides SLA tester -
Thanks