Battery load test w/DVOM

[Doc Harley]

Im on some Harley groups on FB. Most say to hook up a DVOM to check cranking voltage on battery, if the voltage drops below 10.5v to replace battery.
Could that be applied to a snowmobile battery? If so, what would be minimum cranking voltage?

 

[earthling]

The minimum voltages are related to the battery, not the vehicle although specific engine load, temperature, etc will all impact your readings. 10.5 volts while cranking isn't that bad but it really depends on load, size of battery (reserve capacity, etc). Most car manufacturers call out around 9.5-9.8v at max load. You also have to pay attention to how long it stays there. It is not unusual at all to see a battery spike low during initial start (kicking the starter motor over) but recover to around 10.5 to 11v while cranking. Resting voltage should be above 12.2v, ideally around 12.6v resting or you need to charge the battery. Starting voltage should stay above 10.2 to be safe and yes, higher is better, running voltage should be around 14v depending on the system and voltage regulator.

 

[sab2022]

Ditto above but some battery testers have a button to test the load voltage and a needle that shows good/bad battery under load. I use a Schumacher BT-100 Battery Load Tester but there are others

 

[Doc Harley]

The minimum voltages are related to the battery, not the vehicle although specific engine load, temperature, etc will all impact your readings. 10.5 volts while cranking isn't that bad but it really depends on load, size of battery (reserve capacity, etc). Most car manufacturers call out around 9.5-9.8v at max load. You also have to pay attention to how long it stays there. It is not unusual at all to see a battery spike low during initial start (kicking the starter motor over) but recover to around 10.5 to 11v while cranking. Resting voltage should be above 12.2v, ideally around 12.6v resting or you need to charge the battery. Starting voltage should stay above 10.2 to be safe and yes, higher is better, running voltage should be around 14v depending on the system and voltage regulator.

Ty....

 

[Doc Harley]

[ ] Battery fully charged
[ ] Removed FP fuse
[ ] Resting at 12.9v
[ ] 10.8 cranking
[ ] Resting after cranking 12.46v

Earthling, with the battery in question (original), those numbers look ok on a 62° day?

 

[earthling]

[ ] Battery fully charged
[ ] Removed FP fuse
[ ] Resting at 12.9v
[ ] 10.8 cranking
[ ] Resting after cranking 12.46v

Earthling, with the battery in question (original), those numbers look ok on a 62° day?

those numbers look good although I would expect the battery to recover a bit more. Is your 12.9v after sitting on a maintenance charger?

 

[Doc Harley]

those numbers look good although I would expect the battery to recover a bit more. Is your 12.9v after sitting on a maintenance charger?

It was on a tender (assuming same). Yes, 30mins before testing.

 

[earthling]

It was on a tender (assuming same). Yes, 30mins before testing.

Keep an eye on it for the first ride or two. Resting voltage should be closer to 12.6v at 100% charge.

 

[Doc Harley]

Keep an eye on it for the first ride or two. Resting voltage should be closer to 12.6v at 100% charge.

Okie dokie, thank you for verifying

 

[stgdz]

Pulled mine out of storage and resting at 11.3


Anyone know what the yuasa part number is for our batteries? My storage guy forgot to put it on the trickle.

 

[Clintww]

Pulled mine out of storage and resting at 11.3


Anyone know what the yuasa part number is for our batteries? My storage guy forgot to put it on the trickle.

I wouldn't assume that is bad. I would charge it for a week and see if it holds a charge for a week. If you just want to be safe, don't buy a YUASA, buy an Interstate from a store like batteries plus. They last much longer in my experience.

 

[Turboflash]

Pulled mine out of storage and resting at 11.3


Anyone know what the yuasa part number is for our batteries? My storage guy forgot to put it on the trickle.

As suggested, Try charging it fully, let it sit a day, then check voltage. Should be close to 12.6-12.5.
Yuasa part number I believe is YTX20H-BS. 310 cca