Battery / Alternator tester

[Drifter106]

Hi, trying battery/alternator tester. It has 3 LEDs for battery that indicate battery charge ( with car switched off). 3 other LEDs light up when car has engine running to indicate alternator output.

My problem is that with car switched OFF, the battery LEDs light up, but one of the alternator LEDs indicating Charging OK; is also on!

Does this indicate a fault in car circuit?

Many Thanks
Regards

 

[telectrix]

probably just that the voltage is just sufficient to light that LED. in time it will probably go out.

 

[LeeH]

Sounds like a carp tester that's all

 

[telectrix]

same as what i've got on my 3 gang smoke lighter type socket ( for phone,dash cam, satnav.) it's got 4 LEDs indicating the volts. a bit like an approved voltage tester but i won't plug it in the house ring, honest.

 

[Drifter106]

Thanks for replies.

Thought it might be tester at fault, but it does it only on one particular car.

So maybe its as suggested, that voltage is sufficient to light the 4th LED.

Regards

 

[Pat H]

Those LEDs come on at predetermined voltages and the charge one is probably reading that the battery is actually fully charge and some.

My wife's car has daylight running lights added and they are trigged direct from the battery with no switched feed.
When you start up and the alternator kicks in the voltage rises and the lights come on. But sometimes when you switch off the lights stay on for a few minutes as the battery voltage takes a while to settle. I just told my wife it was a design feature.

 

[telectrix]

had similar feature on my 1993 jeep cherokee. the headlights stayed on for a couple of minutes so you could get the key in the front door when arriving home pi$$ed at 2.00a.m.

 

[PEG]

Hi, these testers are only ever a bit of a clue.

A proper DC voltage meter is a better option,as different vehicles have alternative charge methods,and therefore,readings.

Some run several ancillaries,direct,and function using "load shedding",and as such,can be measured at 15V when operating correctly.

11.5V may not light your LED's,yet be just a recently exhausted battery,whist a polarity reversed unit,would do the same.

In short,a device such as described,would be just as efficient at deducing whether or not,a dog was well behaved,just by testing it's nose moistness

 

[Drifter106]

Thanks