Looking for a good SLA battery tester

[kpatz]

I have multiple APC UPSes in my home and sometimes the batteries fail in them, but also I've had the UPSes themselves fail, which means I may be recycling perfectly good batteries.

I am looking for a decent SLA battery load tester that can test the battery, tell me if it's good or bad and report the amp-hour capacity of the battery. Looking online, many lead acid battery testers are geared more for car batteries, and report capacity in cold cranking amps, not amp-hours.

Having one that can test UPS batteries (typically 5-10 Ah) and car batteries would be a plus... so being able to report both Ah and CCA would be nice. I'd prefer one under $100... I've seen them range from $30ish to over $400.

Any recommendations?

 

[AVService]

I have used both of these but neither are $100 and I don't know of one that is legit that will be?

http://www.westmountainradio.com/cba.php

https://www.elkproducts.com/product-catalog/elk-blt-battery-lifetester

 

[WalkIntoTheLight]

Be aware that anything reporting an accurate amp-hour measurement of your battery, is going to have to drain the battery down to 0%. That is not good for lead-acid batteries, even once.

I'd just go with something that is telling you the power (CCA). That will give you a good indication of its health.

 

[kpatz]

It doesn't have to be 100% accurate... I know that would require draining the battery. But some devices, such as the Auto Meter RC300, can give an estimated Ah rating of a battery in just a few seconds. I think you enter the battery Ah rating from the label into the device, it does a load and resistance test, and then it calculates an estimated condition. I've seen them used at Batteries+Bulbs when I buy new SLAs. But this tester is over $400.

CCA measurements are useless on UPS batteries.

I was wondering if a cheaper tester can do the estimated Ah rating... or at least a percentage good/bad that's reasonably accurate without draining the battery to 0%.

 

[WalkIntoTheLight]

It doesn't have to be 100% accurate... I know that would require draining the battery. But some devices, such as the Auto Meter RC300, can give an estimated Ah rating of a battery in just a few seconds. I think you enter the battery Ah rating from the label into the device, it does a load and resistance test, and then it calculates an estimated condition. I've seen them used at Batteries+Bulbs when I buy new SLAs. But this tester is over $400.

CCA measurements are useless on UPS batteries.

Isn't that basically what a CCA measurement does?

Okay, you'd also have to know what the voltage drop on a new battery should be (given a particular load). I presume that the Auto Meter RC300 must have that information built into it?

 

[kpatz]

Isn't that basically what a CCA measurement does?

Okay, you'd also have to know what the voltage drop on a new battery should be (given a particular load). I presume that the Auto Meter RC300 must have that information built into it?

If there was a direct conversion of CCA to amp hours, I could do that, but I don't think they correlate that well. CCA is a measurement of how much current the battery can deliver in a short time to start an engine. Ah is a total capacity before the battery is run down. Different measurements for different applications. A UPS battery won't deliver very many CCAs even if it's a new fully charged battery delivering all its rated amp hours.

Somehow the RC300 knows how to estimate capacity based on an entered (rated) capacity, measured voltage drop under load and resistance. I think it has multiple memories so if you tend to test certain battery types often you can store them and then use them as a basis for comparison. It would also be useful to test a new battery and store its parameters, then compare them in the future to see if the battery has degraded.