Battery Tenders..hmm

[man00]

Just for kicks I thought I would test some tenders..I have two Deltrans one JR one 1.25 amp, Two Black&Deckers and one old Sears maintainer. I fans in 12v outlets turned lights on..ect..alll had some drain. After couple of hours not one of the tenders came on, the old Sears maintainer did and went off couple times....I checked voltage on the batteries that the tenders didn't come on..they ran 10.40- 11.10. I'm not sure when they are suppose to come on but I thought they would at 10.40v for sure??

 

[Industrial Toys]

Weird!

 

[Ford850]

I think they only go into a full charge mode if voltage drops below 80%. 80%-100% the green light should be blinking though, as it's in a lighter charge mode maybe? Then when it hits 100% it goes into float mode.

 

[rademamj1]

Very wierd. You have six battery tenders and none actually work?? I only own two battery tenders made by Genius and over a 4 year period and with dozens of uses, never failed to bring a battery back to operating health, even as low as 11.8 volts on my RV batteries(AGM), but took over 3 days charging.

I remember reading below 10.5 to 11.0 volts most batteries are fully discharged and also permanently damaged. So maybe it's your battery, and not the tenders. Note: This does not apply to Lithium, which can be fully discharged to 0%, and then recharged to 100%.

 

[man00]

All the tenders that didn't come on if you unplug them for a second and plug back in they all go into charging mode.

 

[Industrial Toys]

Same with my recent Chinese cheapie. Fully charged battery, but tender momentarily reads a charging current and percent of charge, then goes to 100%, no current.

 

[Ford850]

All the tenders that didn't come on if you unplug them for a second and plug back in they all go into charging mode.

Well then they are worthless as "tenders" since they are monitoring nothing on their own. Not quite the definition of a smart charger.

 

[WranglerX]

I only have one, its always on generator... Never check the voltages but genny battery is away hot to go when I need it...

Now I have something new to worry about...

Dale

 

[5030]

Keep in mid that the output is in MA so they aren't intended to work under a load. They are designed to maintain a non loaded battery only. I use Yuhasa myself. Never an issue.

 

[rScotty]

I use the BatteryMinder maintainer with desulfator. Cost was just over $125. It does a lot more than just tend to the battery charge. It's restored several batteries that I thought were shot. And using it regularly makes the batteries last longer in seldom-used machines. Cost a bundle, but has more than paid for itself.

I'm an old mechanic and not one to rave, and also have half a dozen other battery chargers including Snap-on's wheel around. The BatteryMinder beats them all and not be a little, by a lot.