So I have never done well with battery tenders.
I read all these people leave their toys plugged in with these things years at a time and never have a problem.
I have been lucky and only lost 3 batteries and nothing catastrophic.

This one just stopped charging I guess.
Had it plugged into a brand new jetski battery that was trash after 3 months hooked to this baby.
Unit was a 1.5 years old and past warranty. Saved it for posterity, and it still will not charge... will do a good job draining your battery though.


This one darn near caught an atv on fire. Left it hooked up and it started overcharging.
I lucked out and caught it before catastrophe but unit and battery were scorching, plastic melting hot.
Same age as the other, little over a year old.

After this I was a little gun shy about leaving these things plugged in unattended. Few years went by
and I thought I would try again.



This is the latest culprit. This one's a little pricier so I felt a little better about trusting it.... wrong.
Noticed that it hadn't charged the battery after being hooked up awhile and the case was hot. Pulled the
seat and the battery was very hot and bulging bad. Lucky I caught it because it was ready to catch fire.
Tested the battery on the tester and it showed 12.89v and 110cca. In other words bad.
CCA on this battery tested 330 about two weeks ago. So much for the BatteryMinder and now
I need a new battery.

So I'm throwing in the towel on the battery tenders before I burn something up.

Going back to the old strategy, which is to test my batteries periodically with this


and if they show low to charge and monitor them with this


when they need it.

No more leaving these things on the tenders for me after these experiences and after I
googled battery charger fires. Here are just a few.

https://www.seattletimes.com/seattle...ttery-charger/

https://www.hagerty.com/media/motorc...ned-out-bikes/

 

Nice pictures linked, but the Deltran Battery Tender is not a charger. I’ve had the same one for 8 years, and it’s still doing fine.

I would never hook up a true charger to a battery in a vehicle, and leave it unattended.

Edit: BTW, the first picture looks like a Jag, they are known to catch fire.

 

I think you've just had a run of bad luck.

I've been using Deltran brand Battery Tenders for over 20 years, and the worst that's happened is one just stopped working after a few years. For sure the life of the various batteries I've had hooked up to them was extended significantly. I keep Reaper on a Tender when she's parked, and have no concerns.

Cheers!

 

I have 4 cars worth over $200K on these tenders year round for years now with no issues at all.
I do have good insurance though..

 

There is a difference between a batter charger and a battery tender. I've also used a Battery Tender for a few years without any issues. Never got hot or over charged my battery.

 

Same as the others.
I've had the same Battery Tender brand plugged into my Corvette since 2005.
The car doesn't get driven much, so it is plugged in for months at a time 24/7.

The Harley gets plugged in also, but during the warmer months may not be plugged in as much.
But over the winter, it will sometimes sit plugged in for several months 24/7 without issues.

 

i've not had good luck with a battery tender either. the one i had started draining the battery instead of charging it (sounds familiar?). i trashed it, and have not replaced it. if the bikes sit for a while, i may put a charger on them to 'top them off', but we ride often enough that it really isn't necessary.

 

The Hagerty article you posted states: "Stick to “smart chargers,” which shut off automatically whenever the battery is full and turn back on when they sense a drop in voltage. They also shut off whenever a short is detected. If you don’t have a smart charger, unplug it if it will be left unattended for an extended period..." The Seattle Times article also states the blame was put on a charger but, as we all know, newspapers don't always get things right. I've been using a tender for close to 20 years and never had a problem with any of them.

 

 

Sorry I posted in the wrong place, I thought it was a general chatty type subject and not a tech question. As for the Deltran, I was using it for its stated purpose. It was hooked to a brand new battery in a jet ski to keep it charged. Came back 3 months later and battery was totally drained and trashed. Other two different brand tenders overcharged and got the batteries pretty hot. I felt like if I wouldn't have caught them I would have had a fire. I may have to cut the BatteryMinder a break though as it does have a temp sensor that I wasn't using, that might have shut it down. Pain in the butt to use that sensor on the bike though. Your probably right though my lucks just lousy, but I feel like I could have had a lot worse problem than a couple ruined battery's if I hadn't caught them in time.