Battery recharging

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4krow

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on: June 25, 2016, 09:30:44 AM
I know that this is the farthest thing from BH topics (or is it?), but after having discovered a dead battery in My RAV4 this morning, I decided to take battery in to get checked. They said it was fine according to their fancy little machine, it just needed recharging. I have a great little battery charger that I have owned for years that will charge a max of 30 amps for about 5 minutes. This battery first was taking 20 amps. Wow, that is a bunch. After 2 hrs of the charger switching on and off, it has dropped to 16 amps or so. Two things bother me. One is that I see nor hear any bubbles being made from the cells or smell the gas that it would normally produce. Secondly, the sensitive needle on the battery charger 'bumps' a tiny bit every so often for no reason that I can think of. I know that some of you guys are into cars, and I bet that you have a few ideas. Yes, I took the battery out of the car, and yes, I have cleaned the post with baking soda/water, using a brass brush. What might I be missing?
 Lastly, the battery is probably 3-4 years old, and has a cold crank rating of 800 CCA. Right now it is at 500 CCA.



Offline mcandmar

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Reply #1 on: June 25, 2016, 09:43:33 AM
Sounds normal to me. Most car alternators are in the 80-140 amp range so a charger at 20 amps wont stress it at all.  Just let it fully charge then put it back into the car, start the engine and verify you have ~14volts across the battery with the engine running.

M.McCandless


4krow

  • Guest
Reply #2 on: June 25, 2016, 11:05:24 AM
 I appreciate the input. After 3 1/2 hrs, the charge rate is down to 10 amps, something that I am more comfortable with. Good idea for me check the voltage at idle when the charge is complete. Thanks