Is this the symptoms of a dead battery?
Discussion
The weekend bought a new and interesting car-related problem that I haven't experienced before - can any of the wise souls here shed any light on it?
I came to start one of my jalopys at the weekend.... it has a battery kill switch that is always switched off to isolate battery when the vehicle is parked to prevent any load from slowly draining current. So I jump in, switch on the battery... nothing... not even a dash light. Off/on, off/on, scratch head, off/on dash lights come on, no cranking.... Headlights and electrical devices work, but no cranking. Check earth, all fine, but no cranking. Source another battery and connect jump leads - motor now cranks! (not enough oomph to start). Disconnect jump battery... no cranking.
So assumption is battery was discharged and I have attached my CTEC charger in 'recondition' mode in an attempt to revive said battery.
The question is - is this a typical failure mode of a lead acid battery? The last time it was used (a couple of weeks ago) it cranked the motor over well and showed no signs of discharge. Two weeks later and having been disconnected for all that time, it appears to have discharged. Could a cell have failed?
I came to start one of my jalopys at the weekend.... it has a battery kill switch that is always switched off to isolate battery when the vehicle is parked to prevent any load from slowly draining current. So I jump in, switch on the battery... nothing... not even a dash light. Off/on, off/on, scratch head, off/on dash lights come on, no cranking.... Headlights and electrical devices work, but no cranking. Check earth, all fine, but no cranking. Source another battery and connect jump leads - motor now cranks! (not enough oomph to start). Disconnect jump battery... no cranking.
So assumption is battery was discharged and I have attached my CTEC charger in 'recondition' mode in an attempt to revive said battery.
The question is - is this a typical failure mode of a lead acid battery? The last time it was used (a couple of weeks ago) it cranked the motor over well and showed no signs of discharge. Two weeks later and having been disconnected for all that time, it appears to have discharged. Could a cell have failed?
larrylamb11 said:
The weekend bought a new and interesting car-related problem that I haven't experienced before - can any of the wise souls here shed any light on it?
I came to start one of my jalopys at the weekend.... it has a battery kill switch that is always switched off to isolate battery when the vehicle is parked to prevent any load from slowly draining current. So I jump in, switch on the battery... nothing... not even a dash light. Off/on, off/on, scratch head, off/on dash lights come on, no cranking.... Headlights and electrical devices work, but no cranking. Check earth, all fine, but no cranking. Source another battery and connect jump leads - motor now cranks! (not enough oomph to start). Disconnect jump battery... no cranking.
So assumption is battery was discharged and I have attached my CTEC charger in 'recondition' mode in an attempt to revive said battery.
The question is - is this a typical failure mode of a lead acid battery? The last time it was used (a couple of weeks ago) it cranked the motor over well and showed no signs of discharge. Two weeks later and having been disconnected for all that time, it appears to have discharged. Could a cell have failed?
Try the wipers. If they slow after several passes you know the earth and connections are sound and it's the battery. If lights are bright but wipers don't work it's probably a bad connection. i/e good enough for the lights but not to take a heavier load.I came to start one of my jalopys at the weekend.... it has a battery kill switch that is always switched off to isolate battery when the vehicle is parked to prevent any load from slowly draining current. So I jump in, switch on the battery... nothing... not even a dash light. Off/on, off/on, scratch head, off/on dash lights come on, no cranking.... Headlights and electrical devices work, but no cranking. Check earth, all fine, but no cranking. Source another battery and connect jump leads - motor now cranks! (not enough oomph to start). Disconnect jump battery... no cranking.
So assumption is battery was discharged and I have attached my CTEC charger in 'recondition' mode in an attempt to revive said battery.
The question is - is this a typical failure mode of a lead acid battery? The last time it was used (a couple of weeks ago) it cranked the motor over well and showed no signs of discharge. Two weeks later and having been disconnected for all that time, it appears to have discharged. Could a cell have failed?
the battery is one of the most oversold parts on a car, even the RAC are getting in on replacing batteries by selling them as battery faults are still one of the most frequent reasons for call out
it is unusual to have a faulty battery nowadays but the owner/drivers often can make their batteries faulty
did you check how long it'll take your battery conditioner (if that's what it is) will take to charge the battery, on mine it's 50 hours, more than two days
did you check the electrolyte level in each cell before charging,
check that no cell is warped,
check the battery posts and clamps do not have any crud on them,
check the main battery lead under the insulation for crud,
check all connections, leads and earths were clean, secure and protected (as above)
if a battery gets sulphated you can buy Batt-Aid tablets and use like the tablets classic owners use when they take their teeth out each night
you'd be better not to use the battery kill switch and to connect up your battery conditioner instead (if that's what you got)
your best bet would be to take the battery off the car and slow charge it then put it back on the car with a battery conditioner
also check your jumper battery and fully charge that - many spare batteries tend to be in poor condition and many sets of jump leads aren't up to the job being too thin
have a look for a John Twist video (no. 10 I think) on batteries for some useful info
I do agree when a battery become unreliable and will not recharge properly then get shot of it a poor battery can lead to faults and hinder repairs - a good battery in good condition and charge with good clean, secure and protected posts, clamps, main leads, earths and connections are always best for any vehicle
it is unusual to have a faulty battery nowadays but the owner/drivers often can make their batteries faulty
did you check how long it'll take your battery conditioner (if that's what it is) will take to charge the battery, on mine it's 50 hours, more than two days
did you check the electrolyte level in each cell before charging,
check that no cell is warped,
check the battery posts and clamps do not have any crud on them,
check the main battery lead under the insulation for crud,
check all connections, leads and earths were clean, secure and protected (as above)
if a battery gets sulphated you can buy Batt-Aid tablets and use like the tablets classic owners use when they take their teeth out each night
you'd be better not to use the battery kill switch and to connect up your battery conditioner instead (if that's what you got)
your best bet would be to take the battery off the car and slow charge it then put it back on the car with a battery conditioner
also check your jumper battery and fully charge that - many spare batteries tend to be in poor condition and many sets of jump leads aren't up to the job being too thin
have a look for a John Twist video (no. 10 I think) on batteries for some useful info
I do agree when a battery become unreliable and will not recharge properly then get shot of it a poor battery can lead to faults and hinder repairs - a good battery in good condition and charge with good clean, secure and protected posts, clamps, main leads, earths and connections are always best for any vehicle
Edited by nta16 on Monday 6th October 13:56
If the battery was fine a couple of weeks ago and has been disconnected ever since then it's unlikely to have deteriorated in this short time - especially if it has been disconnected. It's worth remembering that a fully charged battery will have significantly less power on a cold morning than the same battery on a nice warm summer day (I know it's not that cold yet, but it's worth mentioning IMO).
I'd be looking at the kill switch first - are you sure that it has fully disengaged? If it's partially 'blocking' the full charge from the battery, you'll get the symptoms you describe. i.e. enough power for lights etc. but not the full whack to get the motor to fire up. Never underestimate what strange effects seeming normal electrical components can produce…
Next; did you take a reading from the battery using a multi meter? It's a handy way of diagnosing faults with the battery or a dodgy earth. If you get a reading below about 12.5 volts then you've got an issue with the battery (flat or internal fault). Anything above 12.9 v with the ignition off and the charge is fine, so you'll need to start chasing dodgy earths.
Check the condition of the main strap from the engine to chassis and the black negative lead from battery to body… plus any other you may find fitted. Don't assume they are ok because they are not caked with crud or the lead itself looks ok. Remove them and clean the earth point up with emery paper until it is nice and shiney… then make sure the connections are tight. I tend to change the main engine to chassis lead every couple of years as a matter of course. For the sake of a couple of quid it’s well worth not getting stranded on a rainy and cold morning.
What car are you having problems with? I only ask because a fibreglass bodied car will always have more electrical gremlins than a 'normal' car.
I'd be looking at the kill switch first - are you sure that it has fully disengaged? If it's partially 'blocking' the full charge from the battery, you'll get the symptoms you describe. i.e. enough power for lights etc. but not the full whack to get the motor to fire up. Never underestimate what strange effects seeming normal electrical components can produce…
Next; did you take a reading from the battery using a multi meter? It's a handy way of diagnosing faults with the battery or a dodgy earth. If you get a reading below about 12.5 volts then you've got an issue with the battery (flat or internal fault). Anything above 12.9 v with the ignition off and the charge is fine, so you'll need to start chasing dodgy earths.
Check the condition of the main strap from the engine to chassis and the black negative lead from battery to body… plus any other you may find fitted. Don't assume they are ok because they are not caked with crud or the lead itself looks ok. Remove them and clean the earth point up with emery paper until it is nice and shiney… then make sure the connections are tight. I tend to change the main engine to chassis lead every couple of years as a matter of course. For the sake of a couple of quid it’s well worth not getting stranded on a rainy and cold morning.
What car are you having problems with? I only ask because a fibreglass bodied car will always have more electrical gremlins than a 'normal' car.
Battery has been on 'recondition' cycle on my Ctek charger for 24hrs and now appears fine and charged..... which is odd. It was fit and healthy enough last night to crank the motor over extensively and all appeared fine. I have left it isolated and off-charge over night and will check it again tonight to see if the charge has evaporated....
I've checked everything else, levels ok, no swelling, all connections sound and un-corroded, earth cables and connections all good - so at the moment the symptoms are unexplained, but consistent with discharged battery. How that can happen with the battery isolated I don't understand..... I am going to need to try and replicate the fault to be able to get to the bottom of it, but I still suspect some sort of internal battery failure. Curious....
I've checked everything else, levels ok, no swelling, all connections sound and un-corroded, earth cables and connections all good - so at the moment the symptoms are unexplained, but consistent with discharged battery. How that can happen with the battery isolated I don't understand..... I am going to need to try and replicate the fault to be able to get to the bottom of it, but I still suspect some sort of internal battery failure. Curious....
Hope you get it sorted but one thing I found out the hard way is that battery conditioners won't recover a battery if it's deteriorated too far. I use a Halfords one on my Tuscan and once it's battery had dropped below 8 volts and the conditioner wouldn't touch it. I needed to use a proper charger to revive it.
Paul
Paul
only way to isolate the battery fully is to remove it from the vehicle entirely and have absolutely nothing connected to it (other than charger if charging)
then if it quickly drains itself it's the battery but unless the battery has been not looked after or abused they are very robust unless genuinely at the end of their life, all the "battery problems" I've helped with it hasn't been the battery at fault and a clean and recharge have sorted most
a line of crud, fluid or muck running or spread over the top of the battery enclosing both posts can run the battery down
as I put before using a battery conditioner is better than using a kill/isolation switch
a photo of the battery might be useful
then if it quickly drains itself it's the battery but unless the battery has been not looked after or abused they are very robust unless genuinely at the end of their life, all the "battery problems" I've helped with it hasn't been the battery at fault and a clean and recharge have sorted most
a line of crud, fluid or muck running or spread over the top of the battery enclosing both posts can run the battery down
as I put before using a battery conditioner is better than using a kill/isolation switch
a photo of the battery might be useful
The Surveyor said:
Hope you get it sorted but one thing I found out the hard way is that battery conditioners won't recover a battery if it's deteriorated too far. I use a Halfords one on my Tuscan and once it's battery had dropped below 8 volts and the conditioner wouldn't touch it. I needed to use a proper charger to revive it.
Paul
I don't know about your Halfords unit but I think the old Accumate unit I have will pull up a flat battery but you could be looking at anything from 25 to 60 hours to do soPaul
if your battery is really flat then your right to use a battery charger rather than a battery conditioner just to speed things up, then use the battery conditioner at the end to confirm the battery is full charged
(some?) modern LED chargers so I'm told (don't know) won't even attempt to recharge a battery at or below 6v
I've got an old 4 amp charger with a dial reader it's slow but with the dial I can tell how low the battery is and within 5-10 minutes if the battery is responding and how long it might take to fully charge, I've used it on neighbours cars and it's always pulled the batteries back up, can't say I'm keen on the modern LED display ones, my neighbour bought one but it just didn't seem to fully charge so I put my old 4 amp on and then conditioner, he took the one he bought back, it was a Halfords unit
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