| T O P I C R E V I E W |
| pebe |
Posted - Jan 14 2010 : 12:09:13 PM
With the present spate of bad weather my car (auto) is not getting enough use to keep the battery charged up enough to ensure it can turn the starter.
I have an old charger with rough, rectified AC, with peaks probably extending to 16V off load. But I have read somewhere that a battery should be disconnected to charge it otherwise diodes in the alternator could be damaged. Is there any truth it that? If possible, I don't want to disconnect it because of the hassle of resetting the radio code when I reconnect. |
| 5 L A T E S T R E P L I E S (Newest First) |
| pebe |
Posted - Jan 16 2010 : 5:07:34 PM
I cannot be sure and there is no way of finding out now. The garage said the battery was too flat to start the car and only charged it up. I wasn't able to talk to the mechanic who did the job to establish his reasoning.
In the UK now you can only get as far as the reception - the garage workshop is out of bounds to customers on the grounds of 'Heath and Safety at Work' legislation. The Government has gone mad on it. Would you believe that a surveyor marking out an empty field for a building site has to wear a hard hat? They must think he will get injured by a bird crapping on his head! |
| Aaron Cake |
Posted - Jan 16 2010 : 4:36:46 PM
Are you sure it is not something as simple as a sticky starter? |
| pebe |
Posted - Jan 16 2010 : 2:41:07 PM
My car is used every day and the battery is just 2years old. The fault showed itself because the starter solenoid would not engage after a shopping trip. I suspected the battery but it would run with headlamps and fog lamps on together without dimming while trying to start up, when I tried that as a test. So I suspected a faulty starter and had it towed in (it's an automatic so it would not bump-start). The garage only found the battery was flat. Yes.....I was amazed too!
I think the system's microcontroller measured the battery voltage at the time the solenoid engaged, found it pulled the battery voltage down too much, and dropped it out again. All within a couple of milliseconds, so the lights did not even blink. That's the only reason I can think of.
With hindsight, I think the problem occurred because of driving slowly for several days in snow at low engine revs, with headlights and rear demist and heating fan on. I think the revs were just too low for the alternator to do its job well. But at no time was there any sign of the battery going flat.
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| Aaron Cake |
Posted - Jan 16 2010 : 10:36:16 AM
A good battery should hold a charge for months at a time, even with the small draws the typical automotive electrical system applies. How long is it taking to drain your battery? If the vehicle is not being moved for more then a month, then there are other storage related tasks that need to be performed, not just disconnection and removal of the battery.
Most auto parts stores sell battery maintainers. They are smal chargers designed to be left connected to a battery simply to maintain a charge. They aren't for charging a battery up from dead and are often only able to supply 1A of charge current. |
| wasssup1990 |
Posted - Jan 15 2010 : 8:39:31 PM
It shouldn't be a problem assuming that your battery is good. If you can find the manual see what it tells you to do. If it was me I would disconnect the battery from the car so that the electronics don't get damaged from any peaks in the charging process. I'm sure you'll find out how to keep the radio code when you diconnect the battery. |
