OK Mr C. fair question. I've been around batteries for far too long now (should explain things – well, that and a 1st class honours degree in electronics and telecoms) selling large UPS systems in which the battery banks cost 100K alone. These things are (unlike solar systems) in series, maybe 96x12V lead acid batteries at a time! Yes, series! So, you can imagine what happens when just one battery goes bad. Mostly, the whole string is scrapped. Awful. So, a way to tell what battery is bad, replace it, and keep the rest for a few more years is very attractive.
Here are the strange things you will often see in a “bad” battery:
- Has decent voltage, but won’t start a thing as the capacity has gone
- Has decent capacity, but the voltage is too low
- Has decent capacity, and voltage, but won’t start a thing
- As above, but very fast self-discharge rate
- Physical problems, bulging (oh-er missus)
And a host more even stranger things that combine the above. Many of these faults are repairable! There are techniques to bring these batteries back to life and they can live many more years. This will be a huge issue going on with car electrification: the packs too, are series, high voltage. One cell and they are kaput. So yes, I have sought better solutions for a long time. The biggest problem is time: to identify one bad cell, many times the labour cost is higher than swapping out the entire pack. Recycling is another huge issue. Batteries are heavy and toxic, therefore the recycling plants are miles from the usage points: huge transport costs and huge CO2.
Anyway, sorry for the waffle-on. First of all, regarding this tester, at 40 bucks: buy it and try on some bats you have lying around. I have tons, and did that. It was really easy to use (bluetooth, all the processing and intelligence is on the phone), tiny and light. No huge dummy loads to trek around.
When testing I found it backed up my empirical evaluation of the battery every time. I have attached some pictures of the internals. It’s a Bluetooth chip (the square one, which incidentally has un-tapped USB ports), a blanked out micro-controller, a small load resistor, and some other timing and logic gubbins. As I said before: it is an internal resistance calculator, that has the batteries anatomy (type and capacity) and the various testing standards mapped, to produce an effective result very quickly. Another cool thing is you can input and save battery models, so to repeat test, you just change the leads and hit test (it also logs all the results).
I’d say, in 35 years around batteries, the most useful kit I’ve ever bought. And as above: YMMV, just try it!
