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Thread ID: 124707 2012-05-14 08:52:00 Charging the car battery. Nomad (952) PC World Chat
Post ID Timestamp Content User
1275275 2012-05-14 08:52:00 Hi all,

We have a car that is not being used. The rego has been put on hold, occasionally we jump start it but it just loses the charge in a few days. We don't drive more than around the block incase we get caught.

1. Is it ok to charge the battery while it is still mounted to the car? On this car we have to take off various plastic covers before we can get access to it.

2. It has a big black and red terminal. But beside the big red terminal there is also a small black cable attached. What's that?

3. We have a car battery charger, would any do?
Nomad (952)
1275276 2012-05-14 09:54:00 As long as you disconnect the battery from the car you can charge it up without taking it out. Also make sure there is water in the battery. Thats what a car battery charger is for.
:)
Trev (427)
1275277 2012-05-14 09:57:00 I wouldn't recommend charging it in the car.
Just in case something unexpected happens, from personal experience, things can happen.

Your small black cable could be from your alternator or if it is an older car, a generator.

I would recommend a "trickle charge" (ie slow) if it has been flat for a while.
Also check there is enough water in it and that there is no sediment in the bottom of the battery.
If there is sediment, time for a new battery.

Hope this helps.
Jeff (1070)
1275278 2012-05-14 09:58:00 Get a CTek charger or equivelant. If your battery is normally got a charge on it then you would only need a low power one. Leave it connected all the time in between uses and it will work out when to charge at full rate or alternatively switch itself off until it detects it should start again. Ofthesea (14129)
1275279 2012-05-14 10:01:00 Battery will drain down with clock and possibly ecu. So if you don't want it to go flat when not being used so fast disconnect the battery. Any terminal. The black cable on the red terminal can only be a power terminal
Any charger will do but it would be expensive leaving the charger on all the time
I would leave battery disconnected but charge it for 8 hours or so every 3 weeks on the understanding the charger is a NATO car one.
All this guff of mine is assuming your battery is in good condition.
If you have around $120 buy a solar battery charger from Repco.
You sure can charge a battery on the car with it still connected. But beware if you start the car with it connected it will fry the chargers ass when the alternator kicks in.
prefect (6291)
1275280 2012-05-14 10:06:00 As long as you disconnect the battery from the car you can charge it up without taking it out.

What age is the car? You'd want to be sure that disconnecting the battery wouldn't cause problems with a security coded car radio.
PaulD (232)
1275281 2012-05-14 10:11:00 Car batteries used to loose their charge at a rate of 1% a day.
A LCD clock would not be the main consideration.
Take a voltmeter reading, (sometime after a charge),, 12.6v =fully charged,
12.3 = half charged, 12 is flat!
gradebdan (2186)
1275282 2012-05-14 10:13:00 What age is the car? You'd want to be sure that disconnecting the battery wouldn't cause problems with a security coded car radio.
Its not the end of the world lol with 3 numbers how many combos?
prefect (6291)
1275283 2012-05-14 10:26:00 Some cars, e.g. Nissan, will reset the ecu if the battery is disconnected for more than 24 hours. Then when driven it re-learns for optimal driving settings, after I think a certain distance. Can also lose all stereo channels and settings, which have to be manually re-entered. kahawai chaser (3545)
1275284 2012-05-14 10:31:00 A typical car charger from the local auto store will not keep/charge a Calcium Battery, if you dont know much about batteries then you probably will not know if you have one. A clue is the circular sight glass on top of the battery.

Also it depends on the age of the battery in one of our cars the battery is 5 years old and despite the indication of being charged it is dead and waste of time recharging (yes its a calcium type)

From what you describe if it is not holding a charge after a few days that tends to indicate the battery is on its last legs anyway.
coldfront (15814)
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