Topdon Battery Tester

[shanemax]

I have always found the results from my Topdon tester pretty good, giving cranking amps, voltage, resistance and charging current; It has two quite chunky cables with crocodile clips giving the impression of high amp wires. It started to play up so I took the wiring apart to find 4 very skinny cooper wires. I re-joined them all up with solder and shrinks. It now works fine but the impression of high amp cables is pure bull.
I suppose that's what you call marketing.

 

[Refueler]

I have a Halfords Battery / Alternator tester which has a series of LED's that light up depending on voltage it detects. If engine off / alternator not charging - the bottom 3 lights if all lit - mean battery full charged and most likely good to go. If only 2 - its either not full charged or batts on its last legs ... if only 1 LED - its ready to meet its 'maker' ...

It cannot do a load test - .. but as a general tester - its pretty good.

The only tester I think is any real use ? The two handle jobs that the older garages and scrap yards used to check batts. They DO put a load on and you hear them crackling at the contact points on batt terminals ..

 

[LittleSister]

In my view a load test is redundant if the battery already can't hold a charge - i.e. the voltage falls quickly after being disconnected from charging without a load on it.

Others have described doing a load test without special equipment using a headlamp bulb, or two in parallel, with a pair of leads attached. Fully charge battery, then put the headlamp(s) load across the battery, while recording the voltage every hour.

 

[Refueler]

A bad battery can often still deliver its rated energy as long as the amp demand is light ... but as soon as you hit a start button or heavy load - it fails. The headlamp bulb is really not high enough load.

The battery needs to be stressed to show its real condition. Those old two handle testers did just that ...

 

[shanemax]

Someone with knowledge tell me how a topdon with skinny wires can do a cranking amps test. Mine at about £50i has always been and remains consistent and picks out a
'bad battery-replace'