How To Know Battery Needs Replacing?

[arak81]

Hi guys,

it has been a hectic day for me..went to a garage to get my boot cheked up why it was not opening..before that went to Citroen and they said it will cost me almost £200 to fix it..anyway, local guy couldn't check as they close at 7pm..so got in the car to start and it fails to start...so they used their power unit to charge the battery and now car is up and running and I bought a battery from eurocarparts just in case I need battery changing for tomorrow morning. I can see date, time on the 2nd display are jumping..

Can anyone tell me whether I need to change the battery or it will be okay itself...I got my car battery cheked up on January at halford..and guy said battery was okay.

[coastline taxis]

The boot problem maybe putting a drain on the battery. But the battery wont last forever. How old is the battery and you could always pop into any discount store/garage and ask them to do a load test on the battery

[paul.h]

If you have a volt meter you could check the battery voltage but it would not be as good a test as a load test. Before starting the engine the battery voltage should be about 12.5 volts and once the engine is running it should be about 14.4 volts. If much less than 12.3 volts the battery needs charging or possibly replacing and may not have enough power to start the engine.

 

On the C4 there is a positive battery terminal under a flap just in front of the battery and there is an earth point to the right of the radiator (when looking from the front of the car) which can be used if the car needs to be jump started. So with a volt meter set at about 20 volts, touch the meter red lead on the positive terminal and the black lead on the earth point to check the voltage of the battery. If you do not have a volt meter they can be bought for about £10 from places like Toolstation such as this one but there are similar looking ones from elsewhere and usually yellow in colour  http://www.toolstation.com/shop/Electrical/d190/Electrical+Test+Equipment/sd3348/Digital+Multi+Meter/p11867

 

If you have a meter it can be used to help check the boot problem by checking for a 12 volt supply to the switch and if the earth from the switch is ok. You can also check if the switch works by seeing if there is no resistance across the switch electric connection pins when the switch is used.