Flat battery - what's happening here?

[Naybr]

Haven't used the Chim for a few weeks (work + weather)and I stupidly let the battery go completely flat.

I put a charger on, but it charges for just a moment, then a relay in the footwell clicks, the load increases and the charger clicks out. I'm guessing that this is something to do with the alarm/immobiliser; but I'm curious to know exactly what's happening here. Can anyone enlighten me?

I've now got the car started, and I've bought a trickle charger BTW.

[lesstatt]

Best i can think of to do is charge the battery away from the car, then re-connect and see if all is well or not, this will eliminate the issue

However im sure someone with more knowledge will be along shortly

[SILICONE KID]

Get a Accumate you will never look back..I leave the connector poking out the side of the foot well and just leave it plugged in.

http://cgi.ebay.co.uk/Accumate-Optimate-6v-12v-Bat...

[lesstatt]

SILICONE KID said:

Get a Accumate you will never look back..I leave the connector poking out the side of the foot well and just leave it plugged in.

http://cgi.ebay.co.uk/Accumate-Optimate-6v-12v-Bat...

The OP says he has a trickle charger. thats the same thing as an optimate isnt it ? i got optimate to, very good bit of kit

Edited by lesstatt on Sunday 5th December 12:06

[Naybr]

Yes - I've since bought an Accumate so hopefully I won't have the problem again. Took the car out for a blast this afternoon and all seems fine.

The reason for the post was to try and find out what was stopping the battery charging with a normal charger once it was flat.

I think that the alarm would sound if the battery is disconnected. That said, I'm guessing that a battery charging from flat must reach a point where it causes the alarm to trigger. Presumably this is the relay I heard ..? But even if this is so, would the alarm really draw so much current as to cause the charger to trip out..?

Anyway, that's as far as I got. I just wondered if someone could tell me what was going on here.

[phillpot]

lesstatt said:

The OP says he has a trickle charger. thats the same thing as an optimate isnt it ?

Think the Optimate is a bit more "clever dickie" at sensing battery condition and charge required than a simple (cheaper) trickle charger ?