Snoopy

For what it is worth.....

The key to this statement is the highlighted area. GM technicians at the Proving Ground had mentioned this several times. If the battery is depleted to not provide sufficient "juice" to start, then a vehicle to vehicle boost is o'k. But if the battery is COMPLETELY DEAD (even a shorted cell), use a external boost or charger.

By the way, I killed a completely new vehicle alternator by attempting a charge on a friends very dead battery. That attempt, I was told afterward, blew a diode in my alternator because of the excessive load.

whopper

Sorry but that is so wrong - the alternator DOES charge the battery and tries to bring it up to a predetermined voltage - not the voltage that it is at when the vehicle is started. The charging system is designed to maintain the voltage somewhere between approx. 13 1/2 and 14 1/2 volts which overcomes the internal resistance of the battery - and by doing so, it charges the battery.

Laco

An aternator is rated to charge at a specific rate (amps) and has a regulator built into it to prevent it from charging at a higher rate, which protects the alternator from overcharging. If by charging a low or dead battery diods blow, there is already a problem with the alternator.

dartanian

Ok here's my next question. I got a battery charger but how do you get access if the trunk lid which is electric has no place to put a key in it and open it? Do I have to go in through the back door, put down the seat, pull the cover and charge it that way or is there a way to get the back hatch up if your battery is dead?

Never mind. Just found the thread that says you have to take the cover off and use the screwdriver.

Laco

Its easier to connect the charger under the hood, then you have power to electric latch in the hatch.

Snoopy

Agree with Laco, in the above. I also know/remember owners having problems with the underhood connection. I haven't had any problems connecting under the hood as the Owners Manual suggests. I "jumped" about 5 vehicles now and I have used the suggested connection to use for testing instruments.....no problems.

To dartanian.....your Owners Manual (I know, I know) provides information on gaining access. If you do a search, you may be able to find the thread that I posted that illustrates it a little better.

Here's the thread....

https://www.chevyhhr.net/forums/show...+hatch+release

Don06

The regulator only maintains the proper voltage. It doesn't limit the current that the alternator puts out and a dead battery will keep the voltage low enough so the alternator will put out as much current as it can. It can get hot enough to damage the alternator, especially on the newer alternators. Most vehicles don't have a fuse or circuit breaker on the alternator lead to prevent an overload.

Computers and security systems use a small amount of current and will eventually drain the battery if the vehicle isn't operated. There are small maintainer chargers that you can leave connected long term without overcharging.

Laco

If that were the case the alternator would overcharge the battery, which it does not, as the output current is cut back as the battery charges up. If you had an ammeter on the dash, which all cars used to have years ago, you could see that current cut back as the battery charged up. As far as voltage, they are set to output between 13 and 14 volts constantly.

You are correct about the parasitic power drain, which is why most newer cars will drain their battery in 28 days or so, when the car is not used. As you said the answer to that problem is to keep an intellegent charger connected to the car during periods of non-use. You need a charger capable of maintaining or 'floating' the battery.

J W Davis

I have used the 19.95 solar charger plugged into the aux power plug in the dash to maintain battery power on vehicles that sat outdoors for extended periods with no problems. The low watt output of a solr panel laid on the dash will meet or exceed the slow drain from most electronics. This type of charger is used by a lot of ranchers in the southwest to keep their tractors and such ready to go when needed.

You can buy one at most tool outlet stores like Northern Tools, Harbor Freight, ect.

sleeper

Exactly, a "battery tender"...