Battery charging

Strider590

espresso wrote: »

Not surprised it goes flat if she "turns the car over weekly" but doesn't actually drive it. She is discharging the battery every week and not putting anything back!

And running a car battery flat, then leaving it flat will eventually ruin even a relatively new battery.

ankspon

Why does the AA give conflicting info on the sequence of connecting the leads.

Joe_Horner

ankspon wrote: »

Why does the AA give conflicting info on the sequence of connecting the leads.

Because the only bit that really matters is that the earth connection to chassis (ie: the connection away from a battery) is the last one made. As long as the cars aren't touching metal-to-metal (unlikely in these days of plastic trim everywhere!), you won't get any sparks from the other connections so you can make them in any order you like. Although it's not a good idea to connect both leads to the donor first just in case the other ends are touching each other by accident - short circuiting a car battery with jump leads can be pretty impressive!

red_eye

ankspon wrote: »

What is the correct order for charging a car battery with jump leads,is it positive to dead battery and pos to good battery,negative to good battery and neg to a bolt or similar on flat car.Then when charged remove in reverse order.I ask this because i have looked at various sites and the AA gives a different order to the rest.

you cant charge a battery with another battery. +ve first the -ve on engine or gear box earth strap and never ever connect +ve to -ve

forgotmyname

red_eye wrote: »

you cant charge a battery with another battery. +ve first the -ve on engine or gear box earth strap and never ever connect +ve to -ve

You cant? If i connect a jump pack to a dead battery and leave it for a while the dead battery gains some charge.

Same as connecting 2 car batteries with leads. But what you end up with is 2 slightly dead batteries.

I charge batteries off my jump pack all the time.