Charge new Interstate battery?

[ZebRuaj]

Not helping with any beneficial data ...

But I just picked up a new Interstate 24F from Fleet Farm last night. 11/18 sticker on it. There was only 3 left on the shelf. Just slapped it into the 4Runner and drove away. Didn't even think of charging it up.

Cold spell just hit MN recently, so I'm pretty sure batteries are flying off the rack and keeping supplies fresh.

 

[meep]

Should not be gurgling at 12.1V. Based on the above posts I'm thinking the voltage displayed by the charger is wrong. I'd expect gurgling at voltage top-off / over charge.

 

[neo3]

Originally Posted by Variant_S


I bought a Costco battery on June 8 of this year. The date sticker indicated June 2018. It took two hours before my charger shut off. The charger started at 2 amps and dropped from there.


Same experience here, with multiple Walmart batteries. Stickers either the same month I bought them, or the previous month. I always charge them right after I install them, and they always require some time to reach full charge. My guess is the manufacturer does not charge them 100%.

 

[JHZR2]

Originally Posted by slug_bug
A) the stupid display showing what voltage battery it's connected to and not the actual voltage it's outputting and B) the charger pumping in excess of 15 volts into the battery while charging as indicated by a few posters here as well.


B is true/correct. Ive observed 15.6v under warm conditions, more than I really desire to see.

A makes no sense to me. There's not that much voltage drop or current. If anything, my suspicion is that the charger is using low duty cycle pwm, so at 15A is actually pushing 150A for one second then nothing for the next 9 or something like that. Which is pure speculation, but unless it's something like that, it makes no sense. The voltage measured in the circuit is the voltage in the circuit, other than some very localized redox chemistry on the plates, which is not measured regardless.

 

[JHZR2]

Originally Posted by neo3
Originally Posted by Variant_S


I bought a Costco battery on June 8 of this year. The date sticker indicated June 2018. It took two hours before my charger shut off. The charger started at 2 amps and dropped from there.


Same experience here, with multiple Walmart batteries. Stickers either the same month I bought them, or the previous month. I always charge them right after I install them, and they always require some time to reach full charge. My guess is the manufacturer does not charge them 100%.



It's an exponential type decay, not linear, once out of the constant current mode. Which means the last 10-20% take far longer than the first 80%. Current is driven by voltage. So the higher the voltage, and less of a delta, the smaller the amount of current can flow, so it just charges slower and slower.