I have a 20 year old Battery Tender (HD Brand) which "I think" is still working. The light turns green after a day when I plug it into a battery so I assumed it was working. However, when I connected the battery to the bike - nothing. I used a multimeter to see if there was some additional juice coming out of the battery when attached to the Tender and it did show a jump.

How do you know when your battery tender needs to be replaced?

 

DC clamp ons have gotten cheaper. Tenders have gotten cheap too

 

Have that battery properly load tested. The battery on my Limited failed this spring. Tender light showed green, but bike wouldn't crank. I put the battery on a standard charger, and then ran a load test on it. Battery failed the load test, so I replaced it. Resting voltage was fine, but nosedive under a load.

 

What is it with people on this site and load tests? The question is, does the tender work.

 

Most battery tenders and I'm thinking of the one you probably have only puts out around 3/4 of an amp or about 750 mA . So you won't see much if any jump on a multimeter when you hook up the tender. The best way to check is let the bike sit for a few days without the tender hooked up, check the battery voltage with your meter, preferably digital meter, plug up the tender and check the battery voltage again after the tender light turns green. If the battery voltage is a little higher after that test, the tender is working.

 

You could use a clamp on DC amp meter. But I agree, I think of voltage goes up it is charging.

 

The HD made in China tender that came with my used bike did not work.

 

Depending on the condition of the battery, It shouldn't take a day for the light to turn green
Mine was recently doing this, it was a low battery condition due to a failing voltage regulator.
I don't get out much, when I do it's for short rides, not enough to drain the battery and I'd get 2 restarts so I didn't know it wasn't charging.
My first long ride this year revealed the problem.
The tender was recharging the battery between rides, and I found out the hard way.

 

Never used one since the old 70s sportster days

 

yes!!