Battery Tenders - Yes/No and What size to get?

[Lucas9]

This issue rears its ugly head every so often so I thought I'd write about it.

When you decide to utilize a Battery Tender (or other manufacturer) type charger to maintain your battery, (and I strongly recommend it), please do not waste your time and money on the 750mAmp wall plug in model. It does not have enough beans to do the job on a Moto Guzzi (or other make) motorcycle.

I charge literally hundreds of motorcycles every year in my shop (every motorcycle that comes through the shop door goes onto a charger from day 1) and through extensive trial and error, I have found that the best all around unit size, is a 4A charger. The Battery Tender 4A units in my shop (I have a dozen or more) have always maintained my customers batteries during waiting for repairs and long term winter storage. These particular Battery Tender brand chargers have a 6V switch which I have only used very rarely, but the AGM/Flooded and LiFePO4 settings are fantastic as I have some Lithium battery bikes of my own and customers too.

I also use them exclusively on my personal motorcycles.

The 4A unit can usually (98% of the time) bring back a badly discharged batter, and restore it to full functioning capacity. The 750mA unit will think the battery is fully charged, and shut itself off, when the battery is actually almost discharged.

That 750mA unit just doesn't work at all in my experience or the 2 dozen customers who have brought me dead batteries that were supposedly maintained by that crap unit..

FWIW: Utilizing this exact method of using the 4A charges, my brand new 2012 Stelvio, finally had to have the OEM battery replaced after 10 years! Yes, 10 YEARS! My Ural, has been using the same battery for 5 years now and so have my other 6 motorcycles (batteries in service for many years now). These things work!


JUNK 750mA UNIT:
View attachment 24609




GREAT 4A UNIT

View attachment 24610



One bank of four, 4A chargers on the wall of my shop floor. I really love these things!

View attachment 24611

Thanks for the info, Scott. I've been using the "standard" Battery Tender (1.25A) for years and currently have three (one I have a question about). Based on your post, I have ordered a 4A. I have no batteries that need retrieval, but it often takes several hours or overnight to obtain a full charge with mine, so I believe this upgrade will be useful.
Now for my question: My oldest Tender had the White-colored connector for use with the clamps or the plugs. I don't know how to explain it further, but hope you know what I mean. I'd like to splice in the modern "plug" connector, but is there a polarity issue that I should be aware of? I plan to cut the two wires and connect them, and hope you know what I mean.
Your advice would be appreciated as I would like to use this Tender but do not want to damage any of my bikes. Thanks.

 

[DeadEye]

Hi Lucas,
Can you post a picture of the connector on the unit you have ?
And YES polarity matters !

Don

 

[Lucas9]

Hi Lucas,
Can you post a picture of the connector on the unit you have ?
And YES polarity matters !

Don

I'll go to my garage later and see if I can upload some photos. Thanks for the reply and warning.

 

[scott_m]

Thanks for the info, Scott. I've been using the "standard" Battery Tender (1.25A) for years and currently have three (one I have a question about). Based on your post, I have ordered a 4A. I have no batteries that need retrieval, but it often takes several hours or overnight to obtain a full charge with mine, so I believe this upgrade will be useful.
Now for my question: My oldest Tender had the White-colored connector for use with the clamps or the plugs. I don't know how to explain it further, but hope you know what I mean. I'd like to splice in the modern "plug" connector, but is there a polarity issue that I should be aware of? I plan to cut the two wires and connect them, and hope you know what I mean.
Your advice would be appreciated as I would like to use this Tender but do not want to damage any of my bikes. Thanks.

I have no idea which wire is positive or negative in your description.

Normally the positive is not exposed like the negative.

 

[Raven]

Easy to check with a multimeter.

 

[DeadEye]

Easy to check with a multimeter.

Or which way they were normally attached , Red clip positive, Black clip Negative ?
Hopefully the wires connecting back to the White connector are not black lamp cord !

 

[Lucas9]

Okay, here are the pictures. Some of you may remember the old white connectors. One side of wires are striated, and on the terminal side, the negative wire is striated. On the newer plug, the striated wire connects to the male terminal. I am thinking to join these connecting the plain and striped in kind. I will note objections. Also, I'm a bit of a Luddite when it comes to using a multimeter, but I have one and am open to advice on this front. Lastly, if I have it backwards, will it show by flashing before damage is done? Thank you all for your patience and input.

 

[DeadEye]

Ok so picture 5 ( last one) shows what looks like to me the standard connect all the chargers I’ve seen used ( correct me on this anyone).

I see that pic 1 of the old charger uses another style of connector.
And does not use red/ black wires to indicate polarity…

Did the new charger come with new loop connectors like the old one in pic 4 ?
You could use your connectors with the NEW charger if your bought a pig tail connector like the new one uses and soldered it to your old loops , after testing it with a multi-meter …to make sure the polarity is correct !

Don

 

[Dave.N]

You could get an adaptor.

 

[GTM®]

Some of you may remember the old white connectors.

Sure do. I had several and one ten bank versions, all went up in smoke in the wildfires here.
See above, but you still need a DVM or test light to check polarity. Most all new chargers tell you if reversed.

 

[scott_m]

By convention, the ribbed wire is the neutral or common.

The smooth wire is the hot or positive.