battery tender?
 

hey, will a battery tender charge a new battery? i have a brandnew interstate motorcycle battery that i need to add acid and fully charge. my car charger has a 2 amp and 10 amp setting. too high? (bringing my two bikes out of mothball storage. and will need two tenders.)

I'd use the car charger on the two amp setting.

What is the wattage output of the motorcycle's alternator? Maybe 350 watts? Divide that by 14 (the system voltage) to get the max amperage the battery could see, and use that. So 350w / 14v =25 amps. Now, the battery has its own internal resistance, so it's not going to pull that whole amount.

Interstate recommends a charging rate equal to 20% of the amp-hour rating of the battery. For example, their SRM-27 is rated at 100Ah, so 20 amps would be OK.

Use the lowest charging rate you can. But the battery tender, well, I would think that would overheat if it tried to pull 10 amps. The "battery tender plus" has an output of 1.25 amps maximum, so it might be OK.

You may need a higher amp charge until there is enough stored charge for it to finish via trickling. Optimas (sealed gel, kick butt, expensive) require this if you *fully* drain them.

thanks guys. that acid is scary to work with. chem class memories...