Battery went dead...how do I....

[TheDarkKnightt]

I think the battery is still fine, but I've got a really good couple of questions...

My wife left the parking lights on in the car and it drained the battery. :o

Two questions:

A. Can I use one of these "jump start" mini battery things through the cigarrette lighter to get the car going, and should I treat it as if I was hooking up the battery initially so as not to fry the computer?

B. If I can't use the above, how in the world do I get the back hatch open to get to the battery since it is locked? The rear end is full of stuff that I can't possibly get out through the rear doors even if I put the rear seats down!

Talk about a conundrum! [cussing]

[Huzer21]

Just jump start using the terminals under the hood. I've had to jump mine twice from the parking lights being left on. I didn't do anything special, and all ancillary components worked a-ok after the jump.

[sjonnie]

I think the battery is still fine, but I've got a really good couple of questions...

My wife left the parking lights on in the car and it drained the battery. :o


The battery may or may not be fine depending how long it was left with the parking lights on. The parking lights alone draw 20W total, which would take several days to drain a fully charged battery. So when the same thing happened to me several years back (found the car dead after leaving the parking lights on while at work), I found myself replacing the battery only a few months later.

To answer your questions:

A) You will need to turn the key to position II anyway to activate the in-dash cigarette lighter circuit. The idea is to slowly recharge your battery via the lighter circuit but if your battery is dead flat I doubt this will work enough to allow you to start the car.

B) Doing (A) may well give you enough power to operate the vehicle locks.

Or you could just jump it [thumbup] Even if you jump the car, remember to remove the battery, check the electrolyte levels and fully charge it with a charger overnight.

[n00bkiller944]

Or you could just jump it [thumbup] Even if you jump the car, remember to remove the battery, check the electrolyte levels and fully charge it with a charger overnight.

This right here is the one to do!

[Willy]

Isn't it possible to charge the battery through the terminals under the hood?
Willy

[sjonnie]

Isn't it possible to charge the battery through the terminals under the hood?
I wouldn't do that for several reasons.



A computer-controlled chargers won't recognize the resistance in the system correctly and you risk over-charging the battery.
A charging battery creates hydrogen gas which requires venting, so you're going to want to check your vent tube.
After running a battery flat you should inspect the cells and top up with distilled water. After charging, it is wise to check the voltage & specific gravity in each cell to make sure you don't have a bad cell.
All of this is most easily done with the battery removed from the car.

[JRL]

That's the way you're SUPPOSED to charge it (and jump it).
I've charged several that way, no harm, no foul

[coflynn]

As sjonnie pointed out, the generation of hydrogen gas is a result of charging the battery. If you are charging from flat, this could potentially be a moderate amount of gas building up in a closed environment if your vent was clogged/fell off.

e.g from http://www.wisconsin.edu/oslp/em/compliance/battery_leadacid.htm:

Many lead acid explosions are believed to occur when electrolytes are below the plates in the battery and thus, allowing space for hydrogen/oxygen to accumulate. When the battery is engaged, it may create a spark that ignites the accumulated gases and causes the battery to explode

[Ocean Racer]

I wouldn't do that for several reasons.

[LIST=1]

A computer-controlled chargers won't recognize the resistance in the system correctly and you risk over-charging the battery.


huh???
This is Volvo's preferred method as stated in the owners manual.


For the record, I have found those little quick chargers which plug into the cigarette lighters to be useless. They have never worked in the XC.

Another benefit of having a manual XC is that you can always push start them [thumbup]

[sjonnie]

huh???
This is Volvo's preferred method as stated in the owners manual.

My '02 owner's manual says:

The battery should be disconnecte from the vehicle when a battery charger is used directly on the battery
However, if the battery is being charged via the connecting points in the engine compartment, the battery must be connected.

I don't see any 'preferred' method, nor does it make sense for there to be one. The only advantage to charging in the car is that you don't have to take the battery out, but if your battery is dead it makes sense to check it out thoroughly because there is a distinct chance it is faulty or electrolyte levels will need replenishing. But really, it's up to you, I just gave my advice.

[Willy]

I think the resistance from the terminals under the hood to the battery itself will be quite low, it being
the same resistance through which all power consumers, including the starter circuit, receive current,
so the resistance has to be low enough not to create a meaningful voltage drop in the wiring.
If the evacuation tube on the battery is not installed or connected properly, hydrogen will also contaminate
the air in the cabin while driving the car, so it is important that the tube is in place. I don't see how the tube
could become clogged. As far as I know, batteries don't produce sparks when engaged.
Of course it is possible that in certain circumstances charging the battery through the terminals can result
in accidents, but not if everything is as it should be. It is equally (or perhaps more likely) possible
that an accident occurs while charging the battery on the bench (such as smoking or welding while the
battery is charging). I can't prove it, but I suspect the will be many more report of this kind of accident.
Willy

[TheDarkKnightt]

Thank you all for your concern and help.

I jump started the car from the terminals under the hood. I backed the car into the garage, unloaded the back (which was the hardest thing to do) and then took out the battery. I checked the level in the battery, and only one compartment needed about an eye dropper full. I checked it with one of the glass vial battery checkers and it's at 75% life- pretty good considering it is the original battery that came with the car- but I keep it full of distilled water too.

It cranked right off this morning with no problems at all- I did have to reset the clock though. ;)

The biggest thing I've learned is- I can't store the jumper cables in the spare tire, as they're not as easily accessible if the battery goes dead. I'm going to hang them in a bag from one of the rear seat headrests. I've always been the one to jump others off in the past- first time for me though. :o

[Willy]

From what you write, the battery is probably still ok, so it looks as though the problem is soolved [thumbup]
Good tip about where to store the jumper cables, mine are with the spare tire as well :o
Willy

[Ocean Racer]

I have jump started the car an easy 10+ times over 3 years and have not experienced any problems.