got a 2001 bmw e46 that keeps flattening its battery after a week or 2, battery is only a year old but it still flattens, car is a 330i with auto xenons ect that doesent get a great deal of use, short journeys mostly as its my fathers car,do the solar panal chargers that plug into fag lighters work? the car has a permanent live fag lighter so should get power to battery, cheers

 

They collect sunlight, turn it to electricity.... Not sure what else to say!

 

once a battery has been flattened 2 or 3 times it is largely useless. you need to find the source of the drain and rectify that, charging a dead battery will still limit its life. a car with no external drain and a healthy battery should sit 2-3 months without going flat. if he is doing short journeys that will also kill the battery to some extent as it has little time to charge

 

Can't you get one of those auto trickle chargers?

I've got some on the bikes (two Optimates an one Oximiser (made by Oxford)) but have used them on the bike. They're intelligent in the meaning that they'll sense a drop in voltage and charge them up, once reached optimum voltage they'll cut out..

Disconnecting is easy (uses a Tamiya type plug), costs about Ł30 (when I bought them) and have saved numerous batteries of mine. The 'blade and the hornet are on them now... Probably take them off beginning of summer.

 

Thats what i use every two weeks for two days just to stop the battery drain from alarms !
i got them at a good price to rrp was Ł110 pm details !

 

check to see if you have a drain on the battery...., it's common for the heater hedgehog to cause issues..

 

yes they do work, i got an M3 that the battery only goes dead in the winter months, so leave the charger plugged in and place the solar on the dash, otherwise i leave it charging the spare battery in the garrage and jump off that, Ł24 to buy i seem to remember, see below for example

http://www.theultimatefinish.co.uk/s...lar-panel.aspx

 

thanks for replys, ive ordered one off ebay, ive heard a few people say e46's can have problems with heaters draining battery