“Dead” Battery / Car

G

georgekitchen7

Member
 Bromsgrove, Worcestershire
Hi fellow Z’ers,

My E85 3.0si has been locked away in my garage over winter (first time) and I bought a battery trickle charger to try and keep the battery “alive” over winter when not being driven.

I used this charger to charge the battery to “full” while keeping battery in car, and following the instructions to connect red lead to red positive and black lead to black negative on the battery.

However, after doing this, now the car is completely dead! None of the interior lights work, nothing happens at all when you turn the key in the ignition....

Any idea what’s happened!? Battery charger says it’s full, but have I damaged the battery? Or is the car not “recognising” it?

Is it worth jump starting and seeing what happens?

Thanks so much for your help!

George
 
You really need to measure the voltage on the battery with a meter to double check what the charger is telling you. It should read more than 12.5V. What charger are you using? The cheapo smart chargers from Aldi and Lidl dont restart automatically after a mains blip which catch a few people out.

If all ok then this sounds like a classic case of the ignition switch failing. If you search on here you will see it’s a common culprit. £10 on Ebay.... https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F371189293394
 
Hi ph001,

Thanks for your help! Will get it tested. Yeh it’s a cheap charger from Amazon..

Assuming the battery is dead, should it just be the case of getting a jump start, then car will charge up the battery itself via the alternator?

If the battery has been flat for a while, might this have caused any issues?

Best regards,

George
 
georgekitchen7 said:
Hi ph001,

Thanks for your help! Will get it tested. Yeh it’s a cheap charger from Amazon..

Assuming the battery is dead, should it just be the case of getting a jump start, then car will charge up the battery itself via the alternator?

If the battery has been flat for a while, might this have caused any issues?

Best regards,

George
Click to expand...

Once a battery has been completely flattened it’s not going to be the same again even after charging :(
Rob
 
Yep, I’m afraid the clever bear is correct. If a battery is discharged below around 11v, after 24hrs it will have lost around 50% of its capacity. After 72hrs it will have lost 90%. Some of the more expensive chargers that can do reconditioning can recover some of that back but never it all. The problem is that the battery plates get sulphated which is hard to remove.
 
Thanks guys. If it’s just a new battery I need to buy, then I’d be happy with that! I’m just worried that if the battery is ok (the charger says it’s “full”) then something has gone wrong with the car in terms of not “taking” the power as all lights etc are completely dead.

Can it cause damage to the electrics having a dead battery if it was the battery?

Thanks again for your help, so appreciated.
 
No, there should be no damage. A simple battery voltage test should tell you which direction to go in. I think worst case is probably a new battery or ignition switch.
 
Hi both,

Multimeter showing 2V when should be 12V I think? So likely battery is knackered or should I try removing and charging?

Best regards,

George
 
Knackered. New battery required, and a decent trickle charger like a Ctek Mxs 5.0

I’d recommend the Varta E44 Silver... https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F362151270722
 
Hi all,

Just to update you on this. I bought the recommended Ctek Mxs 5.0 and it worked MIRACLES - totally reconditioned my dead battery back to life.

Amazing.

Thanks for all your help.
 
Sounds good that it worked out. Remember to never start a jumped car and rely on the alternator to recharge the flat battery as it could overheat and kill it. Always best to start with a battery with plenty of power in it and rely on the alternator to keep the battery healthy.
 
If your battery has been down at 2v for even just a few hours it will be permanently degraded. It might work short term to start the car but leave it stood a week and it will be dead. Time for a new battery I’m afraid.
 
ph001 said:
If your battery has been down at 2v for even just a few hours it will be permanently degraded. It might work short term to start the car but leave it stood a week and it will be dead. Time for a new battery I’m afraid.
Click to expand...

Just had to order one today, battery hasn't been right since I got the car, I suspect it was allowed to go flat at the dealers and it's never recovered! Now showing 0V :cry: New Bosch S5 on its way from Tayna
 
Seems I'm in a similar situation, had the alternator stop providing charge to the battery due to a bad connection so the battery was being drained constantly, ended up down to well below 10v showing. Reconditioned with a CTEK a couple of months ago but noticed this last week its been slow to start. Checked this morning, 12.2v showing before starting and 14.5v when running, so it's getting charge fine but not holding it.

Having had the car electrics all cut out, including the engine, on a dual carriageway last time, I'm not keen on repeating this scenario again... :rofl:

Looks like new battery time! Ordered an E44 096 from Tayna for delivery tomorrow.
 
The CTEK is a great bit of kit if you drive your car infrequently.
I’m currently giving my 2 yr old battery a recondition using one. The battery’s healthy enough but I do it as a matter of course now and then, especially when I haven’t driven it for weeks, just to keep the battery in good condition.

Just as a point of interest perhaps; I checked on it late last night and I could hear the stage 6 gassing process going on inside the battery, bubbling and gurgling away. Sounds a bit disconcerting if you haven’t head it before but it’s part of the CTEK’s reconditioning programme.

Nicely charged.
DE28AC50-E9E3-4006-BE90-703C30EA1E01.jpeg

Maybe interesting reading:
http://blog.streetsideauto.com/auto-parts/8-stages-ctek-battery-charger/
 
Well mine has been replaced yesterday and held charge fine overnight, so seems my old battery was indeed on its last legs, be it due to running flat or just getting old (Bosch S3, believe it was about 5 years old).

Anyway, Varta E44 096 installed now for the princely sum of £72 delivered from Tayna/eBay :thumbsup:
 
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