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Low voltage battery


Topic starter

Hi Scotty, 

I have a Honda CRV 2018. A dashcam somehow drained my battery (original) overnight and I was able to recharge it. After charge, the voltage (multimeter) usually reads 12.2 V. Thinking it was time for a new battery after 5 years, I bought a Topdon BT50 tester. All the parameters are good. The tester shows "charge good" but shows at 38%. The battery is rated at 550 CCA and the test gives 552 CCA. The car starts with no issues.

Should I replace the battery? If not, the battery being at a low voltage all the time, will this damage the alternator or charging system? 

How is it possible that at such discharge stage, the battery still gives the full rated crank amps? 

Thank you,



1 Answer
Posted by: @salcedo5

the voltage (multimeter) usually reads 12.2 V.

could be:

  • different battery chemistry (e.g. AGM)?
  • bad connection when measuring. Make sure you're touching bare metal with firm pressure, and there's no corrosion. Lead battery posts should be cleaned off with a wire brush first
  • inaccurate measuring device.
Posted by: @salcedo5

battery still gives the full rated crank amps? 

In my opinion, those Chinese testers are unreliable crap. They are incapable of measuring actual crank amps. They guess.

For a positive verification go to a battery dealer and ask to have your battery load tested with a proper carbon pile tester (which draws actual starting current during testing)


OP is presumably using a TopDon BT50 Tester because that’s what Scotty recommended and promoted in past videos.


Also, auto stores (like Autozone and O’reilly) don’t use Carbon Pile Testers.  Although a dedicated battery place (like you mentioned) would be better.

it's probably worthwhile to test the alternator also