Posted June 27, 200817 yr I recently got a redtop from a friend. It had been sitting up for a good while and was reading 7 volts.So I put my charger on it @ 2amps for 3 days.Now the battery reads 14 volts when I take the charger off. All good right?But when I go to try it out and put it in my car, it wont crank it.So I let it charge some more, and same thing.Battery is fine until you put a load on it.Im assuming its bad, but I wanna make sure, so here this thread is.Hate to waste a battery like that.
June 27, 200817 yr def sounds like it.Charge it back up and let it sit for a day or for several hrs if u cant wait and take a reading off of it, then wait several more hrs and take another reading.If it keeps dropping, definitely bad.You can also take it to Autozone.Tell them what the CA rating is on it so they can properly test it. Only takes about 3 minutes.
June 27, 200817 yr Author I let it sit overnight last night, it stayed at around 13.7 votes for 12hours.Just wont handle a load.WTF.
June 27, 200817 yr charge it, crank it just one time and if it wont start, stop!Check the voltage. IF it's below 10.0, it's shot to hell and back.If it's at that or higher, wait about 1 minute and recheck. If the voltage hasn't risen above 12.3v within a minute or so, it's damaged as well.
June 27, 200817 yr take it too advance auto and let them put it on there charger/tester, should take about 30mins
June 27, 200817 yr Author charge it, crank it just one time and if it wont start, stop!Check the voltage. IF it's below 10.0, it's shot to hell and back.If it's at that or higher, wait about 1 minute and recheck. If the voltage hasn't risen above 12.3v within a minute or so, it's damaged as well.Ok, lemme go into a little more detail.Say I put a load on it, and stop, it'll jump right back to 13.5.Thats what I don't understand.I thought maybe its a bad/weak cell inside but I don't know much about batteries as far as that stuff concerns.
June 28, 200817 yr u gotta put a load like a cranking load. make it ur starting battery and to get it to start your ride for about 3-5 seconds then stop if it doesnt start.Recheck voltage at this time. then check it again about a minute later.
June 28, 200817 yr Author u gotta put a load like a cranking load. make it ur starting battery and to get it to start your ride for about 3-5 seconds then stop if it doesnt start.Recheck voltage at this time. then check it again about a minute later.Thats what I did, put it in my car as the only battery.It did not crank. Didn't even turn it over, but checked voltage after and it was in the 13s. :confused:
June 28, 200817 yr Well, let me tell you what i know and go from there. Other than what i'm bout to say, gotta have it tested-Autozone told me that you give them the CA rating on the battery. They hook the batt up to the tester and send that load to the batt for 3-5 seconds. This example was tested on a batt whose float is 12.6v, stock lead acid battery.The batt dropped to 10.3-10.5v but then started rising into the 12s. He stated if the batt doesn't reach 12.4v or higher then it's damaged. The battery reached 12.2v and the test failed the batt. We tested the batt because it wouldnt crank the engine but ALSO, it wouldnt even run his dome light or his door buzzer!, now explain that one with a rest reading of 12.6 before load! It baffled me but that's what happened.Of course he bought a new battery and viola, everything worked fine.
June 28, 200817 yr Author Well, let me tell you what i know and go from there. Other than what i'm bout to say, gotta have it tested-Autozone told me that you give them the CA rating on the battery. They hook the batt up to the tester and send that load to the batt for 3-5 seconds. This example was tested on a batt whose float is 12.6v, stock lead acid battery.The batt dropped to 10.3-10.5v but then started rising into the 12s. He stated if the batt doesn't reach 12.4v or higher then it's damaged. The battery reached 12.2v and the test failed the batt. We tested the batt because it wouldnt crank the engine but ALSO, it wouldnt even run his dome light or his door buzzer!, now explain that one with a rest reading of 12.6 before load! It baffled me but that's what happened.Of course he bought a new battery and viola, everything worked fine.Yeah, It must be a bad battery.Shoot. It was free tho, at least I tried.
June 28, 200817 yr It had been sitting up for a good while and was reading 7 volts.It's time to say "Goodbye redtop".
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