Charging the Battery while still connected to the car

[randu2020]

I took the battery out of my car and charged it overnight. I woke up and the thing is still charging. Fearing something might happen with all the darn computer parts on my car I hooked it back up not wanting to leave it off for too long. The smart charger said it is still not fully charged so is it ok to hook the charger up with the battery connected????????? My car hooks into the side posts of the battery leaving a set of top posts I can easily hook the charger cables too.

[BodybyFisher]

I have done it, but its best to disconnect the battery from the vehicle, always disconnect the negative cable first

It should have charged, have your battery load tested it may have a short or bad cell

[winterset]

I have done it, but its best to disconnect the battery from the vehicle, always disconnect the negative cable first

It should have charged, have your battery load tested it may have a short or bad cell

Check the age of the battery. - if older than 4 years, just replace it.

If your battery was completely dead, it went through a deep cycle. Generally a battery that were on the edge will never recover from this state.

Also when connecting it, clean thoose terminals really good. inside & out.

A bad battery generally will not do any permanent damage to your cars computer, but will have a striking impact on your nerves!!

[Cadillac Jim]

Never bet anything important on the health of a horse, or a battery.

A trickle charger or a battery maintenance charger is OK to put on the car. If you have a fast charger, i.e. anything bigger than a lunchbox or more than 10 Amps, never hook to to the car, always remove the battery cables. And, whatever charger you use, hook it up before you plug it in or turn it on to avoid hydrogen explosions set off by the spark, and be *very* careful not to hook it up backwards.

[hjb981]

I have done it, but its best to disconnect the battery from the vehicle, always disconnect the negative cable first

It should have charged, have your battery load tested it may have a short or bad cell

I use a "smart charger" (from CTEK), and it uses a quite low charge current. I use it quite often to charge two marine batteries for a raft with an electric Minn Kota motor on it. I think the batteries are 90 Ah (or less), and the charger outputs 3.6 or 4 amps at the most, so even with a battery that is only partly discharged, it can take more than a night to fully charge it. Even if your car's battery has less than 90 Ah (maybe 70 or so) it could still be normal with longer charging times if your charger also has a rather low output.

I don't think that leaving the battery cable off does anything to the computers. Has anyone experienced problems from that?

[BodybyFisher]

Not that this is the pinnacle of information but you can see how varied the responses are. I'd rather be safe than sorry, and disconnect the battery from the car

http://answers.yahoo.com/question/index?qid=20080325070145AAW4zFQ

[KHE]

The only time I'd remove the battery from the car is if I were going to replace it... There is no need to remove it from the car to charge it. I usually hook up the cables first and then plug the gharger into the wall.

[Cadillac Jim]

I think posts on Yahoo need to have a CYA element in today's litigious society. I wouldn't worry with a trickle charger or battery maintainer. In fact, the 1997 FSM says to put a battery charger on the car if you are going to be fiddling with the car's diagnostic mode for more than a half hour with the engine off.

Of course, if you hook it up backwards, then everything is on you.