Technical slow crank, no jumpstart, battery has charge

[elmend]

hi

I have a 94, the battery is not old but i had to recharge it twice for different reasons, once forgot lights on, and another was parked for a couple of weeks and it drained.

After recharging it the car worked well for a couple of weeks and then suddenly one day after driving around for a while i stopped and it just wouldn't start again.

I get a slow crank and lights dim while turning the key to start, but i tested the battery and it has charge, about 12, but jumpstarting with another car didn't work.
Since i drove it for days the battery was recharging so the alternator is ok i guess, what could be the problem?, could it still be the battery that is gone bad even if it has charge?

thanks

 

[SteveNZ]

Too many assumptions and not enought facts!

You need to load test the battery or use a hydrometer. Checking for 12V is useless.

Check its charging correctly too, around 14V when the car is running with the lights on, it maybe as low as 13.5V with a flat battery though

Start with that as see what you get. Its probably the battery, but if it isn't we'll look from there. Also, the battery should not go flat after only 2 weeks, its either a dud battery or you have a drain somewhere in the car.

 

[elmend]

Thanks for the reply ,I took it to the shop bump starting it, and they load tested and it was just the battery that died, i think it dropped to about 6v from what i could see.
He told me it's because it was a crap brand battery, not sure if he was trying to sell me one as they sell new batteries too.

Anyway i changed the battery and it now works fine,but i will be testing if it charges correctly as you say.

I asked him why it didn't jumpstart, he said maybe the contacts were not right, but i tried once with a car and another with a mechanic truck and none worked. can this be the case or should it have jumpstarted?

 

[SteveNZ]

If it does not jump start with a flat battery, but it will start with a new battery the problem is the jumper leads or the supply battery. You'll be surprised how many sets of jumper cables are out there that cant supply enough current to start a car.

 

[maddogmorg]

If it does not jump start with a flat battery, but it will start with a new battery the problem is the jumper leads or the supply battery. You'll be surprised how many sets of jumper cables are out there that cant supply enough current to start a car.

yup had that problem, the ones we've got were fine for the 1.4 but the 2.0 needs more powah, the leads just get Very hot but don't provide enough power to start.