Will Prowse Approved.
Battery Capacity Testers
After a few years, you need to test the capacity of your system. You can use a shunt (click here to learn more) to test the capacity of your entire battery bank. But if you are not pulling good numbers or the voltage cuts out for no reason, you need to take your system apart and perform a capacity test on each battery. (affiliate links below)
In a nutshell:
- Take battery bank apart and disconnect all inverters/mppt/chargers/loads.
- Charge each battery to 100%.
- Connect a capacity tester and run the battery all the way down to 0%.
- Use your capacity test results and compare these results with the data sheet of your battery. If there is more than 10% loss in less than five years, you might have an issue.
$35 capacity tester
$35 capacity tester
This one does work and I have used it a lot but it is pretty limited on what it can do. Run it at 75% of its rated current so it doesnt melt down. I havent had this one meltdown yet, but all the cheap ones before it did. Try to run a fan on it as well. Keep it nice and cool.
$69 capacity tester
$69 capacity tester
I like this one a million times more than the one above, but it is almost double the price. Easier to use, better interface and you can connect it to a computer.
$229 CBA V Pro
$229 CBA V Pro
Lab calibrated capacity tester that I used for years but it has been on backorder for over a year. I love this thing but you just cant buy it anymore. Maybe find one used on ebay?
$600-$7000 ITech IT8511A+ Electronic load
$600-$7000 ITech IT8511A+ Electronic load
I have three of these and they are not cheap. They are absolutely fantastic but the software is horrid. It is calibrated and certified.
I can pull the same accuracy with the cheap units above. The main benefit of these load testers is the increased current capacity. It cannot cycle a battery though, so I use custom order battery cycling machines now to do capacity testing. But I still use these electronic loads when all the machines are taken.