Car battery testing..?

[robwizard]

My trusty little Mitsubishi Colt wouldn't start this morning and I would like to figure out if it's the battery or the starter motor. It clicked a lot when trying to start but that's all that happened..

I can test the voltage of the battery but is it possible to check the cranking amps?

Thanks,

 

[merryman]

Not easily, battery testers check the voltage under load anyway. You need to charge it up before checking. I guess a rough guide would be to check the voltage when the starter is being turned, can't remember how many volts is OK but I guess above 9v.

 

[rtbcomp]

You need a drop tester like this

https://www.amazon.co.uk/Sealey-BT91-Battery-Drop-Tester/dp/B000R9ZPJK

https://www.amazon.co.uk/dp/B000RODAM4/ref=psdc_1939120031_t4_B000R9ZPJK

https://www.amazon.co.uk/gp/huc/view.html?ie=UTF8&newItems=Ceba23c98-218f-4d91-8766-c4b7c4587fcb,1

 

[Rannsachair]

i have a tester I use, it is a useful tool if you have a lot of batteries: https://www.ebay.co.uk/itm/Portable...h=item33fc4d4ee0:g:-5IAAOSw3J5Zeagt:rk:1:pf:0, i paid about £20 for it. It does a test cycle and puts battery under load, found a battery I thought was dud was fine, and another that I thought was an electrical fault was the battery.

 

[123hotchef]

take it to a local spares shop they will test it for free

 

[knighty]

charge it up for a good 24hours (if possible) and see if it still acts the same way

 

[bletchmonster]

I'm always amused by our local battery factors that will happily come outside and test your battery with something the size of a pocket multimeter and will authoritively tell you your battery capable of hundreds of amps is shot at.

 

[Wozzaaah]

I'm always amused by our local battery factors that will happily come outside and test your battery with something the size of a pocket multimeter and will authoritively tell you your battery capable of hundreds of amps is shot at.

One of these maybe?
I bought a used one a while ago, seems like a good bit of kit.

 

[Alan Reynolds]

In days of old, batteries were always tested by the old boy in the garage, with a 'tong tester'. A similar device to that first link. I'm amazed at the price of that one though. It's only a shunt with an ammeter across it. Less than a fiver's worth of components in it. Sticking a hefty shunt across the battery is really the only way to test them. The little devices you can buy, don't really cut the mustard.

 

[Ashley Burton]

i have a tester I use, it is a useful tool if you have a lot of batteries: https://www.ebay.co.uk/itm/Portable...h=item33fc4d4ee0:g:-5IAAOSw3J5Zeagt:rk:1:pf:0, i paid about £20 for it. It does a test cycle and puts battery under load, found a battery I thought was dud was fine, and another that I thought was an electrical fault was the battery.

I have the same one & very handy bit of kit!

Drop testers aren't used as much these days as they're not 100% safe. Batteries can explode using a drop tester.

 

[Wendelspanswick]

In days of old, batteries were always tested by the old boy in the garage, with a 'tong tester'. A similar device to that first link. I'm amazed at the price of that one though. It's only a shunt with an ammeter across it. Less than a fiver's worth of components in it. Sticking a hefty shunt across the battery is really the only way to test them. The little devices you can buy, don't really cut the mustard.

The little modern ones don't have to load the battery so much as they are more precise in measuring the internal resistance of the battery.
I can't fault mine...
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/362488754847
It's picked out a faulty battery that was dragging down the pair of 12v batteries that run my lorry.

 

[voipio]

How old is the battery? Although some cars manage to keep going with 10 year old batteries, not everyone is so lucky. I've had to change batteries after 3 years. A good simple indicator is how much the interior light dims during starting. If there's any suggestion the battery is beginning to go downhill, i.e. the light dims quite a bit during starting, then I would tend to change after less time than 10 years. If a battery has deteriorated, performance wise, it's usually in the winter that you find out. Has the car done a lot of short journeys, queuing in traffic, in the dark? What is the battery voltage, measured at the cigar lighter/auxiliary power socket, during a decent run? If it gets to 14.2V or higher, then the battery is shot.

It's always worth checking the battery connections at both ends i.e. battery and other end.

 

[jerrytug]

I have the same one & very handy bit of kit!

Drop testers aren't used as much these days as they're not 100% safe. Batteries can explode using a drop tester.

Not disagreeing, but if a battery can explode using a drop tester, couldn't it explode with starter motor loads as well?

In my personal opinion, a drop tester which actually takes tots of energy from the battery, to heat up some big resistor coils, is the only way. Those little plastic gadgets can't work surely?

 

[jerrytug]

The little modern ones don't have to load the battery so much as they are more precise in measuring the internal resistance of the battery.
I can't fault mine...
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/362488754847
It's picked out a faulty battery that was dragging down the pair of 12v batteries that run my lorry.

Interesting

 

[slim_boy_fat]

I hope I'm not about to pee on your chips , but a friend of mine has a Colt. She was experiencing random starting difficulties, sometimes perfect, next time no go.

She replaced the battery on advice from a garage but it didn't solve the issue. Turns out the ECU on some Colts can fail due to water ingress. Plenty of info on Google about the failure.I If she'd had to buy a new replacement it was going to cost more than the car was reasonably worth.

The local main dealers were excellent and stored the car in their premises to see if we could source a used part with all the additional black boxes, keys etc which would be needed. We lucked out & found all the required bits (they need to be matching, and iirc from the same car) on the 'Bay which they then fitted. Still cost her several hundreds of pounds though

As said, I really hope I'm wrong and it is simply the battery .

 

[robwizard]

I'm trying to think of it possibly displaying any other signs of the battery being done for. I guess the lights probably do dim a bit when it's starting.. hard to say really. We have something in work that's been described as an "amp clamp" which might be suitable for testing the battery? I have no idea to be honest haha.

@slim_boy_fat I'll look into that! I was hoping it wasn't the starter.. now I'm also hoping it's not the ECU!

Cheers guys

 

[angellonewolf]

batterys are not that expensive for petrols

 

[tom 748]

to test,12.4 volts standing,start it up,should be over 14v,if under 12 v,bin it,when you start it,if you dont get over 14v,your alternater is iffy

 

[fizzy]

In days of old, batteries were always tested by the old boy in the garage, with a 'tong tester'. A similar device to that first link. I'm amazed at the price of that one though. It's only a shunt with an ammeter across it. Less than a fiver's worth of components in it. Sticking a hefty shunt across the battery is really the only way to test them. The little devices you can buy, don't really cut the mustard.

My mate was an auto electrician - quite a young chap so always interested in new gadgets.
After a few years he ended up using a an old prong tester and a solid copper soldering iron heated by a gas burner!
The smaller battery testers are a waste of time. His prong tester was just a very heavy resistor - no meter - you just looked at each cell - the one's that didn't bubble were the dead cells.

 

[zzr1200]

Either a proper drop volt tester across the battery or a multimeter across the battery terminals and try starting the engine on the key and watch the multimeter for the reading.....

https://www.ebay.co.uk/p/Durite-Dis...3%26rvr_ts%3Dae9d22781670aade24c173b0ffc6d6c6