why does a battery lose charge?

Answer 1

You might have something that drains the battery for example, a boot light that stays on. One extreme case I've known is the starter motor leaking the +pos to earth.

Also, a battery that goes dead quite quickly (overnight) tends to mean a duff cell. Once started and running, you might be able to switch off and restart, but left for a few hours causes problems.

In time batteries drop sulphate off their lead plates and falls to the bottom of the battery. Some battery manufactures increase the depth of this gap to increase the warranty on the battery. Once the sulphate builds up and touches a plate, that cell goes down.

Batteries get a charge on journays of approx 11 miles or more. If you do short trips, get a heavy duty calcium battery or top the battery up with an automatic charger.

Also, is the charging system on the vehicle working correctly.

Answer 2

If it is on a car (can be applied generally too) then it would be one of a few things.

1. As already said, the alternator output is poor, and you may need a new one. If your car has a 12v system you can check this with a voltmeter across the battery when engine running - should be about 13.5v while charging.

2.There is no or low levels of electrolyte / acid in the battery which means that it won't fully hold it's charge.

3. Neither of the above apply and the fault is in the electrical system, with something staying on, such as a boot light, interior accessory or similar. Also could be if there is a poor earth causing voltage to leak, effectively draining the battery away.

Answer 3

There are 2 opportunities: a million.) The battery has began to short internally, which potential it really is time to get a clean battery. or 2.) there's a small floor interior the constructive fringe of the wiring gadget, which slowly drains the battery even as the alternator is off. a thanks to attempt for the latter is to dosconnect the constructive cable from the battery, and, utilising a multimeter set to ascertain resistance, verify between the constructive cable and the body of the motor vehicle. If there's a floor (often a worn spot in some wire's insulation) you'll comprehend at modern-day. if it quite is the case, then you genuinely will obviously ought to music down the spot it quite is grounded, good success. The period in-between treatment is to disconnect the battery each and anytime the motor vehicle is stopped. If there is not any floor detected, then that's the battery, flow get a clean one.

Answer 4

A battery holds a charge a load draws current, depleting the charge?

Answer 5

now cars draw on the battery to keep the computer on low power even when not running , so battery need a charge every third day

Answer 6

How old is your car?

How long have you owned this car?

Have you checked your battery for a label with a date on it?

If the answer to any of the questions above is more than three years, buy a new battery.

It's most likely become sulphated.

Answer 7

There could be a short draining the current from the battery.

Answer 8

You might need a new battery or it may be your alternator failing. Could be something else. Take it to a garage they can test your battery and alternator.

Answer 9

possibly because the alternator is weak or not charging at all

Answer 10

alternator knacked or your leaving radio/lights or something on