battery

[jimgod]

hi all,

would 1st of like to thank you all for brilliant site.

lets get down now to help i need,
use car daily for work only 8 mile round trip.
not used xmas day
boxing day flat battery.
bought new battery and fitted no problems.
used car for 4 days. battery flat again.

put old battery back in now fully charged.
no problems since.

car needs some turning over to start from cold.
is this normal ? 260e
no other problems.
input would really be appreciated

 

[Frank Patten]

Disconnect a battery cable and with the car all switched off, put a meter between the battery and the cable. Turn on the burglar alarm. The discharge should be less than 50 milliamps. My W124 discharges at 10 milliamps with the alarm off and 40 milliamps with it on and takes 3 1/2 weeks to lower the battery to 7 volts which will not start the engine. If the discharge is excessive you will have to search for the fault.

 

[malcolm E53 AMG]

How old is your original battery, if its older than 6 yrs its probably past its best. Did you replace it with the correct rated battery from Bosch, Varta or OEM. If not it may be the new battery or charging system.

This time of year is a battery killer and as you say the car requires a good turnover to start, and only gets short runs, you should really be fitting a heavy duty battery.

 

[jimgod]

thanks for feedback frank,
regards alarm, it has one fitted but dont arm it. but it goes off when battery flat and i open bonnet. checked ampage weekend with old battery in, car running and lights on, using 3.4amps. battery was at 13.4 volts with engine running.

wondering if it is the underbonnet blanket thing. sorry dont know what it is called! is missing on mine so engine and battery really cold up here.

 

[jimgod]

thanks malcolm,
old battery is 4 years old by receipts i got with car,loads of by the way.
new battery is varta 62ah as stated for my car,
will be taking it back weekend as not holding charge.
will replace with heavy duty if possible.

 

[jimgod]

by the way frank, did you know your link does not work ?

 

[Frank Patten]

Hi jimgod,

Thanks for info on my website, I am looking into it.

When you check the drain on the battery you must do it with everything switched off. Including the engine. With the engine running I would suggest the 3.4 amps is the charging rate, not the discharge. Also, 13.4 volts is the charging voltage. Switch everything off and test.

Although winter is hard on batteries, it has been unseasonaly warm recently, so extreme cold is not the main problem.

If you have already installed a new battery, it would still be wise to check the discharge rate, in case that is what is flattening it.

 

[jimgod]

hi frank,
thanks for info again, up until now still using old battery, been ok for 3 weeks now.
will take new battery back tommorrow as off work,
will check voltages and ampages weekend again as left meters at work.
will update later.