car just wont hold a charge!!

[kasman21 0]

Hi guys

 

had my rado sat on the drive for 6 weeks as seeling it. It has been seriously cold i know but I was stupid and didn't start her weekly and take her for a run!!

 

Now i just jumped her as battery dead!! took it out for 20 mins, drives and runs perfect as usual. parked it up and nothing battery dead again! or at least I think it is. What would the issue be?? the battery is only 6 months old and its a high end calcium one!!

 

would it be the battery, alternator?? or anything else to test!!

 

any thoughts would be appriciated!!

 

cheers

[CorradoVR6-Turbo 0]

does the battery have charge after a run? does it trurn over or sluggish?

[kasman21 0]

it has a tiny amount of charge i think but doesn't turn or even attempt to turn!! really weird!

[joby 0]

You need to charge it with a trickle charger as the alternator only holds the power that is in the battery originally and yours was probaly dead after six weeks.

[kasman21 0]

whatis a trickle charger?

 

i would have thought the alternator would charge the battery fully even if dead??

[CorradoVR6-Turbo 0]

the alternator will charge the battery but will take some time,is your alternator charging the battery?

[flusted 0]

needs a good overnight charge

[kasman21 0]

i dont know if its charging the battery, the only thing i know is i can jump the battery and the car starts fine, but when i turn the car off, and try to restart it nothing happens!

 

i haven't got a clue

[CorradoVR6-Turbo 0]

you need to get it checked out,or at least buy a multimeter to test for charging yourself.

[dr_mat 0]

A 20 minute drive won't fully charge a car battery, no hope mate. You need a good hour's run to come even close to a full charge, particularly from totally flat.

The alternator will deliver at most 70 amps to the battery, which means just over an hour required to fully charge.

 

Your battery might well be dead, but so far I think it's just flat. I've written out in various other threads how to test all that, so go do some searches ...

[kasman21 0]

cool,ill see if i can charge it overnight and see if that resolves it.

 

thanks for the responses

[herisites 0]

Most battery chargers wont charge if there is too little charge in the battery already, a trickle charger will give it enough charge to get a big charger to charge it though.

[dr_mat 0]

Most battery chargers wont charge if there is too little charge in the battery already

I've never heard that before - where did you see it? Not saying I know everything there is to know about batteries but I can't think of a physical mechanism for that to happen, so I'd like to find out more ...

[gogsboy 0]

These seem to work quite well.. http://www.ctek.com/EN-GB/Default.aspx

 

I got the middle of the road one from Costco for £35

[dr_mat 0]

Great if you have the car garaged all the time - trickle chargers will keep the battery spot on, but for the rest of us we'll just have to keep jump starting the bleedin things.

Also note that trickle chargers aren't suitable for recovering a totally flat battery. Read the spec - they'll do "maintenance charge" on larger batteries only, full recharge can only be done for smaller batteries up to about 30 Ah.

 

TBH you can't really go wrong with the £30 "Challenge Extreme" chargers from Argos either. Made-in-china of course, but what isn't these days?