Looking for a motorcycle battery load tester

Hi Folks,
I'm needing a load tester for lead acid motorcycle batteries. I've been told that testers designed for autos don't work well on motorcycle batteries. I've also found that professional units cost about $300.00. I'm willing to build one if someone knows of an available design.
TIA
Bill

The new ones are kind of complicated. They are computer controlled and they run loading routines and data log the results so you'd have to write software to do that. I just use the starter. Crank the starter with the plug wires pulled and measure the battery voltage cranking. 9.5 and above is a winner, between 8.5 and 9.5 is one foot in the grave and below 8.5 is toast.

Westmountainradio.com. The CBA III.

bountyhunter wrote: The new ones are kind of complicated. They are computer controlled and they run loading routines and data log the results so you'd have to write software to do that. I just use the starter. Crank the starter with the plug wires pulled and measure the battery voltage cranking. 9.5 and above is a winner, between 8.5 and 9.5 is one foot in the grave and below 8.5 is toast.

Thanks BH! I wish I could just monitor the voltage as I run the starter. The problem is that I don't have power where the bikes are stored. If I have a battery problem I swap the battery out and then have to decide if it's worth charging once I get it back to my shop. I've got enough bikes here, I suppose I could set one up as a test bed.
I've also been thinking of using a 2.5 OHM 100Watt resistor to load it for 30 seconds or so and then recheck the voltage.

ayeckley,
The CBA III, what ever it is, costs $600.00. Too rich for my application.
Thanks
Bill

Thanks BH! I wish I could just monitor the voltage as I run the starter. The problem is that I don't have power where the bikes are stored.

Get an analouge moving needle volt meter across the terminals and watch the needle drop, flick the headlights on for extra load. A simple battery 'drop tester' is just a big power resistor with cooling fins and a voltmeter. You might be overthinking this...

Usual suspects if excess volt drop would be the battery leads. ground point, solenoid connections the starter motor. Old battery wire and crimps can corrode inside.

Bounty, maybe ground the HT wires on the motor with some old spark plugs, I read somewhere that the transistorised ignitions can get damaged otherwise.

Tyrell Corp wrote: Thanks BH! I wish I could just monitor the voltage as I run the starter. The problem is that I don't have power where the bikes are stored.

Get an analouge moving needle volt meter across the terminals and watch the needle drop, flick the headlights on for extra load. A simple battery 'drop tester' is just a big power resistor with cooling fins and a voltmeter. You might be overthinking this...

Usual suspects if excess volt drop would be the battery leads. ground point, solenoid connections the starter motor. Old battery wire and crimps can corrode inside.

Bounty, maybe ground the HT wires on the motor with some old spark plugs, I read somewhere that the transistorised ignitions can get damaged otherwise.

Maybe so. Probably better to have the plugs on the lines.

The other option is just to crank the engine when it's stone cold with the fuel tap turned off then you knw it won't fire anyway. You just need a couple of seconds of engine crank so the meter reading on the battery will settle.

KZQ wrote: The CBA III, what ever it is, costs $600.00. Too rich for my application.
Bill

Hmmm. I'm seeing $160, but i understand that might not be justifiable either.

Hi ayeckley,

When I searched for CBA III I found a site selling software licenses. The full monty was $600.00. I searched around the site but could find no description of a battery analyzer.

Here's where I ended up:

www.westmountainradio.com/product_info.p...ucts_id=cba_software

Searching again I did find the device for $160.00.
Thanks for the suggestion. I'll look it over.
Bill

The other option is just to crank the engine when it's stone cold with the fuel tap turned off then you knw it won't fire anyway. You just need a couple of seconds of engine crank so the meter reading on the battery will settle.
1979 KZ-750 Twin

I guess two slightly different tests:

1) Battery 'Drop test' seeing if the battery can sustain an acceptable voltage during cranking for up to 15 seconds.
This is done with the battery disconnected.

2) checking for volt drop from battery terminals to starter when cranking. Taking Voltage readings across battery terminals then to both cables would narrow down exactly where the fault is...or better still replace the lot if the original cables.


A good battery with bad wiring will pass 1 but fail 2






A pair of jump leads and 5 minutes to narrow it down or eliminate either the battery or wiring seems easier than
buying software licences, or am I overthinking this ? :dry: