Battery tester

sfc2113 said:
I got one of these last year to and installed with my Battery selector switch
and thought I would share.

It works great for the price, and will give an accurate reading even when the engine is running.



http://www.harborfreight.com/cpi/ctaf/d ... mber=65928
If can't give an accurate reading with the engine running since you will be loading the alternator in addition to the battery.
It also doesn't significantly load the battery as a real commercial load tester would. So you get what you pay for.
 
It can't be a load tester, it's a waterproof voltage indicator bar chart style.
 
BobP said:
It can't be a load tester, it's a waterproof voltage indicator bar chart style.
It could draw some load ( a few amps) based on the wire size. That will probably help identify a dead battery or a bad cell but then again, in both those cases, the motor wouldn't start. One way to tell if it draws any load would be to hold the button down for 30 seconds and see if anything gets warm or hot!
 
For the cost of 6 bucks ?

Perhaps for a 12 volt lantern battery, not any battery in a boat.
However the instructions may read to turn on the headlights when using, makes sense then at 6 bucks.

Just turn on the flood lights on the boat and that's worth about 9 amps. If it's dead or near dead, lights will go dim or out in 2 seconds.

Still doubt for 6 bucks it applies any load whatsoever, and if so it ought to be fused.

It reads voltage and shows as a state of charge it appears. And when the alternator is working voltage picks up - as usual.

Here's a battery load tester, gets hot enough to make toast.
Key word is carbon-pile!
 
Load test at West Marine

Guys-

West Marine stores generally have a very sophisticated digital battery tester that can, in a few minutes check the battery condition. They use these to test batteries that a customer may want to return under warranty.

If you are nice to the store manager he will probably test any battery you bring in to see if it's up to par. Doing this at the beginning of the season should alert to any possible bad battery before you are out on the water!

Rod