Anyone ever link more than one battery to a battery tender?

[Rusty Pig]

Does anyone know if you can link two or more batteries up to a trickle charger such as a battery tender? I'd like to do this on my motorcycle and boat batteries during the winter but thought I'd check with the experts before I blew up my batteries, bike, boat and garage.

 

[El Toro]

https://www.derbycycles.com/cgi-bin/eShop/i...d=8247079.97001

To have the correct voltage, you'd want to rig them up in parallel. Every additional battery would reduce the impedance seen by the tender. I don't think it would be a good idea.

You can get a bunch of pig tails and move the tender from battery to battery.

You can buy the fancy 4 unit tender.

 

[Badcat]

Electrically, that is a bad idea. :angry2:

4 battery unit: good idea

 

[Scab]

Why is this a bad idea? I've charged multiple batteries with a standard charger.

 

[Rusty Pig]

https://www.derbycycles.com/cgi-bin/eShop/i...d=8247079.97001
To have the correct voltage, you'd want to rig them up in parallel. Every additional battery would reduce the impedance seen by the tender. I don't think it would be a good idea.

You can get a bunch of pig tails and move the tender from battery to battery.

You can buy the fancy 4 unit tender.

Do you think it could damage the batteries? I was planning on hooking up these batteries at my cabin during the winter and won't be around to switch them otherwise I would do as you suggested.

 

[KSFJR]

My big tractor is a John Deere with two large batteries to start it. I have always used one battery tender on it and have noticed no problems. They are matched batteries though so that might make a difference if one was a large and one small, one no maintenance and one maintenance, etc.

As to the one unit to service 4, the one unit costs about as much or more as 4 individual units. I have 8 or 9 units for everything that I have as they are all over the place and one really wouldn't work.

Chester

 

[J-DADDY]

Why is this a bad idea? I've charged multiple batteries with a standard charger.

+1

JC

 

[El Toro]

This is another thread like an oil or an octane thread where you can do it, and folks do, and everyone's got an opinion, and the technical issues are ignored.... like maintaining correct voltage by hooking them up in parallel, and being concerned to not overload the unit with a reduced impedance. Nothing bad happens immediately when you do it, so folks figure its OK.

I've got to learn to keep my mouth keyboard shut. <_<

 

[RenoJohn]

Why is this a bad idea? I've charged multiple batteries with a standard charger.

+1

JC

+2

lead batteries charged in parallel, from a single charger DC source, ...no problem what so ever. No different than golf carts and thousands of other scenerious.

 

[Scab]

Some techno-info with diagrams showing both series and parallel hook-ups.

Charging multiple batteries.

 

[J-DADDY]

Some techno-info with diagrams showing both series and parallel hook-ups.Charging multiple batteries.

Scab-

Thanks for the info.

When I made the previous reply, I should had included that I have only done this with similar batteries with no problem.

JC

 

[MotownJJG]

I used my battery tender Jr. on some gel batteries I used for ham radio field use.

It broke.

No problems before that using the tender on single batteries of a similar type.

Could'a been me.

Could'a been the batteries

Could'a been the battery tender.

Whatever the case, I don't do that no more...

 

[Jon]

Battery Tenders have a certain amperage output that is designed to charge a single battery. That is, a certain amount of current is put into the battery depending on its state of charge, resistance to the charge, etc. This amperage, as I understand it, is based on a single battery. While you certainly could hook it up to more than one battery (properly!!), you would compromise the current sensing ability of the Tender and therefore it's ability to completely charge multiple batteries. That's why they make units for two, four and many batteries.

If hooked up properly, you probably would do no harm, but you won't get the full charging capability of the Tender. For one, I say do it right.