Discussion
Okay, so I try to start the Z4 this morning and click,click,click but no cranking over. Thought it was a stuck starter motor but recovery guy diagnosed a flat battery (showing 10v according to him). He jumped the car and it started no probs and after 5 mins he shut it down and started again first time with the key. Left it running for 30 mins and tried it again and again it started first time. Then about 2 hours later same back to the clicking of the solenoid and failing to start.
Now the battery has been in the car from the start (7 years old) so should I replace that and see how it goes or should I hand it over to someone else to check for something draining the battery before I shell out for a battery?
Now the battery has been in the car from the start (7 years old) so should I replace that and see how it goes or should I hand it over to someone else to check for something draining the battery before I shell out for a battery?
The battery is 7 years od. Chances are that is what is wrong. Don't waste money getting the alternator checked, get a new battery anyway - it must be on the verge of needing replaceing in any event. If that does not do it then go get the charging system checked over. Your money on the new battery would not be wasted
It's easy! Sit inside with the engine idling, switch on the interior light, gently rev the engine to a couple of thousand revs and watch to see if the light brightens. Do it again with the headlights on and the fan heater running on high to load the alternator. If the interior light visibly brightens then the alternator is ok. If this test isn't clear then go the multimeter route, but it always seems to work for me.
CCA is Cold cranking amps
RC is Reserve capacity
AH is Amp Hours
CCA
is the number of amps a battery can support for 30 seconds at a temperature of 0 degrees F until the battery voltage drops to unusable levels.
RC
roughly how many minutes the battery can supply ample power without falling below the minimum voltage needed to run your vehicle.
AH
the storage capacity of deep cycle batteries. This is the maximum sustained amperage drawn from a fully charged battery over a certain time period to a point where the battery is at 100% DOD (depth of discharge), (dead).
Regarding CCA and RC, the higher the better.
As for the Amp Hours, I'm not sure but suggest you check the BMW spec and copy it
I went through all this when replacing batteries on a fleet of speed boats - I just went for a good quality known brand with better stats than the original
RC is Reserve capacity
AH is Amp Hours
CCA
is the number of amps a battery can support for 30 seconds at a temperature of 0 degrees F until the battery voltage drops to unusable levels.
RC
roughly how many minutes the battery can supply ample power without falling below the minimum voltage needed to run your vehicle.
AH
the storage capacity of deep cycle batteries. This is the maximum sustained amperage drawn from a fully charged battery over a certain time period to a point where the battery is at 100% DOD (depth of discharge), (dead).
Regarding CCA and RC, the higher the better.
As for the Amp Hours, I'm not sure but suggest you check the BMW spec and copy it
I went through all this when replacing batteries on a fleet of speed boats - I just went for a good quality known brand with better stats than the original
When I had the Golf which developed an alternator problem which ended up draining the battery completely flat on one occasion, it never was right again after that and struggled to turn the car over. New battery sorted it.
Was later told that these types of sealed battery are a bit like that sometimes, in that if they're run completely flat that they will never perform perfectly again. This could of course just be salesman codswallop, which I happily fell for!
Was later told that these types of sealed battery are a bit like that sometimes, in that if they're run completely flat that they will never perform perfectly again. This could of course just be salesman codswallop, which I happily fell for!
Edited by ccr32 on Monday 9th May 10:59
Gassing Station | BMW General | Top of Page | What's New | My Stuff