Battery Charging – Lead-acid wet or AGM

We can charge and check batteries that were purchased from us. We can check batteries that were not purchased from us, but we cannot charge them. If you have a battery that was not purchased from us, you can find charging instructions below:

Powersports – Manual charger. Check fluid if possible. 2 amp max but 1 is better. Divide battery “Amp hour” or “Ah” rating by the amperage of charger and add 20% for losses to heat.

Automotive – Manual charger. Check fluid if possible. 15 amp max but 6-10 is better. Charge “dead” batteries (won’t start the vehicle) for 24 hours *in-a-row*. If you take/turn the charger off, the clock resets.

Larger industrial or agricultural – Manual charger. Check fluid if possible. 20 amp max but 10 is better. Charge “dead” group 31 batteries (won’t start the vehicle) for 24 hours *in-a-row*. If you take/turn the charger off, the clock resets. 4D/4DLT/8D – charge for 48 hours *in-a-row*.

If fluid is low, refill with Saskatoon tap water (or any drinking water) to the bottom of the “collar” inside the fill port. Failure to fill battery PRIOR to charging can lead to hydrogen buildup and explosion – think Hindenburg + sulfuric acid. Sealed “maintenance free” batteries have a “recombiner” valve that condenses vapors and drips them back into the cell but some fluid is still lost. Most batteries these days are maintenance free. Once enough fluid is lost the battery must be replaced.

Automatic chargers will work only if the battery being charged is already *mostly* charged. In general, old/dumb chargers work better but are happy to blow your battery up. Automatic/smart won’t blow your battery up but won’t charge a dead battery.