Hi All:

I last drove my car in early November. Then it got cold, etc. In Dec and Jan, I trickled the battery to make sure it had a charge. Today, I jumped the car and went for a 30 minute drive--some of which was a bit of a thrashing. But the little bike battery still will not start the car. It reads a bit over 12 volts, but do you think the capacity to start the car is gone? If so, is it because I let the charge get too low when it was cold outside?

If I replace this one, it will be my fourth battery in this car in roughly 9 months!

--Thanks, Chris

Dunno about a bike battery but a healthy, car battery should show 13.7volts, 12volts means a cell has turned up it's toes or some other terminal condition (assuming it's fully charged).

Modern batteries don't like being deep discharged, once flat for a couple of days, they're dead

[Edited on 29/1/07 by UncleFista]

There are good trickle chargers and bad ones - to have several batteries bite the dust after a couple of months means that something is drastically wrong.

Optimate chargers will keep them alive for years

When the car is left are all the circuits isolated,? do you have cut out switch,? check for leakage current that flattens the battery. Is it bec or cec and what is the amp hour capacity of the batterys you have been using. Are they man enough for the job?.
Regards Steve Evans.

I m8 - we have a small charger which we got from ebay... it was wired up wrong, check it is charging! On the original wiring the plug (for cigarette lighter) was positive to outside - this is incorrect. It kept blowing the inline fuse I put in! I fitted a small cigarette point (female) in the car for easy trickle charging, which it is!

As said they do not like to drop below 11V, if it does it's likely dead.

BTW - our battery is over 1 year old and very healthy, it is also running very small voltage to the clock which is part of the original clocks. Our battery is a YUASA original replacement for the Kwak zx12r cost about £24 IIRC.


Steve

The first few batteries were due to charging issues...

I must have let my battery drop too low. So on the new battery, how do I keep it from discharging so much? Do I keep a self-monitoring trickle charger on it and only take it off to drive it? Do I store the battery indoors?


--Thanks, Chris
--Thanks, Chris

Hi Chris - the battery shouldn't discharge itself in a couple of months - it would have to be pretty bazookad to do that. Have you checked the "dark current" with a multimeter when you switch it off? Are you sure the regulator is right? Battery volts should be12.7 ish engine off & no load and 14.3 ish engine running.
Hope you get to the bottom of it, sounds like you're spending more on batteries than gas!

Bob

A bike battery will discharge itself in a month if it's not used and is left in a cold garage connected to a car or bike even without any drain. I've naffed a few just by my own negligence. The one on my bike now has been on 2 years and is still healthy because I've made a point of using it at least once a week for half an hour or so. Try an Optimate on it and see if it goes into deep cycle mode, it puts 20v or so into them to desulphate the plates and sometimes re-energises them but I wouldn't hold too much hope. I used to lay mine up for winter and treat them as disposable.

Hi Chris

Also check your engine earth strap, earthing through the engine mounts alone is often not sufficient especially when its cold, and even if you have a good earth strap, the junctions will corrode over time especially in winter.

A jump lead clipped to the -ve battery terminal and onto the engine block is a quick way of checking, if it turns over much better with that attached then you're earth is not good enough.