How To Tell If Battery Tender Is Charging. The Battery Tender Junior charger will automatically monitor and maintain the battery at full charge. This morning I go out to check and the indicator light is solid red indicating charging.
1 Poor electrical contact. If red charging light is on and never goes off it may mean that the battery has one or more cells shorted so it is drawing most of the Battery Tender voltage away and basically working the poor thing trying to keep the rest of the battery cells up and not enough to ever reach full surface charge level. Measure the batterys voltage without then with the tender.
This means that its battery can only take a fraction of the energy it is offered and the charger inside of it is fooled.
If you want to get a battery use-able fast then you should use a charger. Have battery load tested. But when it reads 124 volts the battery has attained a 75 charge level and it could still be charged further there would be no danger. Hook it up to a known good battery connect a voltmeter across the battery before and during the tenders connection to the battery.
