Best battery on the market?

[emirc 0]

HI there folks, i drive '92 Corrado VR6 with a little over 200.000KMs on it...

 

I bought it 2 years ago and i already changed two batteries due to drainage/short trips (first was when i bought the car, Varta Blue something, and now i got to replace Bosch Silver)

 

My car produces around 0.2 A when everything off including alarm, and around 0.3 A when Cobra alarm on...

I drained it few times almost to death so i think my Bosch have lost a lot of it's 66Ah original capacity. One time I left a car sitting for a week with at that time brand new Bosch, and couldn't start it...

Time to replace it but im not sure what's the best one. I was reading in some auto magazine test recently, and original VAG batteries have showed results the best out there.

Because i do a lot of short trips, i assume my afterrun fans/electric water pump is a main drain source here so what im looking actually is a battery that charges quickest.

Original VAG battery is rather expensive but im ready to buy it if it could solve my problems.

 

Any help/advice appriciated...

[Neil VR6 0]

I think the battery isn't your problem, it's the lack of use your car receives. Lead acid batteries hate being completley drained as it massively shortens their life. I'd get a normal battery and then either drive your car on more long journeys or buy a trickle charger for when your car's parked up for long periods.

[___Dubstar___ 0]

i have exactly the same problem, even bought a very expensive optima yellow top, it lasted longer than the others but i still killed it and am having an arguement with the supplier to see if it is in warranty. Anyway i recently bought a new one fron the VW dealer - got the biggest one i could find a passat turbo diesel one, it just fits and is over 100 amps - so far so good but i also bought an expensive trickle charger like neil G60 sugested as you will always have that problem if its left for long periods - good luck keep us posted.

[jonnyboyo 0]

EMIRC the 2 batteries you have had are good ones. Theres obviously something draining the battery when your not using the car, and it is 15yrs old now so the wiring could be a little tired. A car should be able to be left for a week and still be able to be started. I'm sure when they were brand new they didn't have this problem.

 

Maybe get an auto electrician to have a look to try and source the drain. It could be something really simple. Good luck.

[dr_mat 0]

0.2 amps will completely drain a perfectly functional 64Ah car battery in 13 days. Utterly flat. And the battery only needs to drop to about 30% charged before it will no longer be able to start the car.

 

It's not the battery, it's the car ...

 

As said above, either get and use a trickle charger or disconnect the battery when you're leaving the car standing for any length of time.

[emirc 0]

EMIRC the 2 batteries you have had are good ones. Theres obviously something draining the battery when your not using the car, and it is 15yrs old now so the wiring could be a little tired. A car should be able to be left for a week and still be able to be started. I'm sure when they were brand new they didn't have this problem.

 

Maybe get an auto electrician to have a look to try and source the drain. It could be something really simple. Good luck.

 

Two of the best auto electricans in my city were examining car and both of them are saying it's perfectly standard for modern cars equiped with ECU and lots of electronics to be using up to 0.5A when car is completely off. They also checked alternator and starter and said it's fine, not telling me out any volt/amper numbers though... :roll:

 

What they suggested me is, as 0.2/0.3A isnt too much by their opinion, that i should check myself if car turns some electrical devices after long time period sitting shut-down. I dont know what procedures Corrado VR6 is going through when you switch it off besides afterrrun fan/auxiliary pump.

When i activate my alarm system, it does some electrical operations up to 15 seconds...

So maybe my VR switch on some electrics 1-2 hours after it's ignition is turned down... :?

[Yandards 0]

You should really be looking at a period of about 4 weeks before you need to charge the battery, get the wiring checked.

 

You can do it yourself by sticking a multimeter on the battery and pulling a fuse at a time, when the current draw goes you have tied down the system that is causing it.

[dr_mat 0]

0.2 or 0.3 amps is normal, agreed. Get a trickle charger.

[jonnyboyo 0]

Have you checked that the boot light doesn't stay ON when the boot is shut? Apparantly this is a common corrado prob. Flip one of the rear seats down when your in the car and take a peek.

 

If its safe to do so, maybe leave your alarm deactivated for a day or two to see if its that thats causing the drain. Maybe use a mates garage whilst the alarms off.

[dr_mat 0]

Boot light is what 10 watts? P= VI so that's nearly one amp. It's not that - he's only losing 0.2 amps ..

[Kevin Bacon 5]

Yeah the boot light staying on would do the job nicely! It flattened my Optima Yellow top in 3 days.....

 

0.2 amps shouldn't phase any battery. I think there is bigger, underlying problem somewhere.

[emirc 0]

Thank you all for your comments.

 

I am just back from installing and testing new 75Ah battery. Only problem was that i needed A LOT of cranking, i think 5 times (every try was around 5-6 seconds) to get VR6 started :? It seems my cranking time has doubled this week since im having battery problems. I only needed one short crank before to get it going...

Just today i noticed that my instrument table light dims (while motor idling) when i start switching power-hungry devices like fogs, rear window heating, ventilation, etc...

I have to mention that i recently installed uprated headlight loom, and switching low beams and high beams have no impact on diming instrument table light whatsoever, at least not the visible difference.

Could my alternator be on its way out?

 

I will try to keep you informed about further gremlin activities on my C. :evil:

[chubbybrown 0]

I'd be looking for broken wires from the alternator

[dr_mat 0]

Basic tests with a voltmeter (I've typed this out about 20 times now!):

 

engine off, volts across battery terminals, battery "rested" for 30 minutes:

voltage % charged

11.5 20

11.7 40

12.0 60

12.3 80

12.6 100

 

If you have less than ~40% charge, it likely won't have the capacity to crank the car.

 

engine on, volts across battery terminals (test alternator):

no electrical load: 13.8-14.2

lots of electrical load: 12.5-13.5 volts

 

Any less than these means your alternator is probably iffy, or you have such an extreme load that it can't cope. Note that the ECU will shut down if the voltage drops below I think 8V during cranking.

 

But I'll state again - 10 days without use will render your car unable to start, even if your battery is at 100% capacity at the start of those 10 days. And bear in mind that if it's at 40% capacity because you've only done short journeys it'll only take two-three days before it's unable to start the car. And this is all if you've *only* got the 0.2-0.3 amps drain that seems to be normal for Corrados.

[Yandards 0]

(I've typed this out 20 times now!)

 

Stick a guide on the wiki instead then ;)