Purchased about three weeks ago. Hooked it up according to manufacturers instructions, red positive lead to postive post on battery, black negative lead to chassis.

Plugged it in and red light on steady, green light flashing, indicating unit was correctly hooked up and charging battery. However after 3 weeks the green light is STILL flashing. According to the manufacturers instructions the green light should be on steady when the battery is fully charged.

The car starts fine, so I don't think it is a problem with the battery. Anybody know what might be the problem. Any help would be appreciated. Thanks.

 

Mike, hook the tender to your battery posts and it will work like a champ. Red to + post and Black to - post!!

 

Mines hooked to the post's green light on no flash only when first plugged in .

 

Anybody know what might be the problem. Any help would be appreciated. Thanks.[/QUOTE]


The above answers are correct . . . you had an inadequate ground. Use the posts and not the chassis.

I have a couple of these Tenders and they work great.

 

csexton

Thanks for the reply. I hooked it up as you suggested. The red light is on steady as before but the green light is now off, does this sound right to you?

Mike

 

That's how i always hook mine up.

 

That's perfect. Mine stayed red over night and is now steady green. I guess it takes some time for fully charge.

 

Sounds good! Should flip over to green when the battery reaches full charge!!

 

I guess so . Mine has been on for 24 hours now and hasn't turned green yet. Guess I'll keep waiting. Thanks for the reply.

Mike

 

Note: if the battery is old and down, these little helpers will not work. That´s what I learned the hard way. They are not able to charge a nearly dead battery.

Maybe you first bring it up to OK condition with a normal battery charger.

Frederik

 

GIve it a couple of days and if you don't get a green light charge the battery with a conventional charger. These units are for, mainly, maintaining and provide less than an amp when charging.
Conventional charger's output is 10 amps or more.

 

Somethings not wright I have mine grounded to the chassis and its working fine

 

If something was left on, like a maplight, or something elso causing excessive current drain, the Bat Tender will stay in the green flash mode, it thinks the battery is not yet fully charged.

 

If you get a good ground it will work fine. The negative battery terminal is just an easy place to get a good connection.

 

Richin Chicago

You were right. I gave it a couple of days and now have the green light. All is well. Thank you everyone for the help.

Mike

 

FWIW, if you have a battery that reads less than 3V on a multimeter, the Battery Tender Plus will not be able to start the charging cycle. The lamp will flash red on and off indicating the battery is too weak to charge.

According to the manufacturer, you can "trick" the charger into starting the charging cycle on a battery that low by connecting the charger and then jumping the dead battery from a good battery to temporarily raise the threshold voltage above 3V.

Once the charger's lamp has a steady red glow, you can remove the leads from the second battery. The charge cycle will take 2-3 days but should be able to restore the battery's function, providing there are no dead cells, of course.

*As always, use this tip at your own risk.*

 

Mine did the same thing. My other cars battery got discharged and it took my regular charger to bring it up enough for the tender to take over.

 

I thought I remember my instructions saying that when you have a red light only, it's charging. When the green light flashes, you're at 80% charged. When green light becomes steady "on", you are fully charged, and charger will "float" from there on....

 

Sorry to revive such an old post, but I just recently purchased a battery tender plus and had a question. Although the instructions say to attach the neg (blk) lead to grounded chassis, I noticed many of you just attach to the neg battery post. For all the battery experts out there, why do they instruct you to use the grounded chassis point instead of the battery post? There must be a reason?

The instructions also state when charging a battery that is outside the car to attach a wire to the neg post and then connect the neg lead off the charger to the cable.

Thanks for all your help.

 

Don't know that I would call myself a battery expert, but the instructions are written that way for safety and liability purposes. It is possible for batteries to emit an explosive gas that could be set off by a spark when connecting the negative lead if the Battery Tender has an electrical current running to it. The purpose in using a grounded chassis point is to keep the negative lead and any possible spark as far away as possible from the battery, thus lessening the chance of an explosion. When connecting the Battery Tender, I connect the positive lead to the positive battery terminal first, then the negative lead to the negative battery terminal next. The last thing I do is connect the Battery Tender to the house's electrical outlet. When disconnecting the Battery Tender, I reverse the above order, disconnecting it from the house's electrical outlet first, then the negative lead and then the positive lead. This too will lessen any chance of a spark near the battery. These same safety precautions should also be kept in mind when using a battery charger or when jump starting a car from another car's battery.

Note that the above instructions are for negative-grounded vehicles which the C5 and most cars today are.

Hope this helps.