Do Battery Tenders fail?

[MT home]

I have a Battery Tender Plus brand charger that is about 12 years old, and I'm not sure that the charging circuit is correctly functioning. I plugged in the B.T. into each of our four motorcycles yesterday (all in an unheated garage, at about +8 F) and none of them seemed to need any charging, despite the fact that they have been sitting at least 6 weeks since last getting plugged in to the charger. The red and green lights on the B.T. still work, and go almost immediately from red to green. Battery voltages measured at the standard SAE pigtail showed from 12.39 volts to about 13.2 volts, depending on which of the motorcycles I checked. Three of the four batteries are "sealed" type, and the 07 FJR is the newest of the batch. In November, the non-sealed battery stayed "red" [charging] for a few hours; the other three didn't need any charging (based on the red-green status lights). Given how cold it is and has been (negative teens F for a week or so), I would think that a bit of charge would be needed by the batteries.

Is there any good test procedure(s) that I can do to determine whether the B.T. is still working correctly, short of buying another one to check whether the results are the same?

Thanks in advance for your collective wisdom.

 

[FJRAL]

I have a Battery Tender Plus brand charger that is about 12 years old, and I'm not sure that the charging circuit is correctly functioning. I plugged in the B.T. into each of our four motorcycles yesterday (all in an unheated garage, at about +8 F) and none of them seemed to need any charging, despite the fact that they have been sitting at least 6 weeks since last getting plugged in to the charger. The red and green lights on the B.T. still work, and go almost immediately from red to green. Battery voltages measured at the standard SAE pigtail showed from 12.39 volts to about 13.2 volts, depending on which of the motorcycles I checked. Three of the four batteries are "sealed" type, and the 07 FJR is the newest of the batch. In November, the non-sealed battery stayed "red" [charging] for a few hours; the other three didn't need any charging (based on the red-green status lights). Given how cold it is and has been (negative teens F for a week or so), I would think that a bit of charge would be needed by the batteries.
Is there any good test procedure(s) that I can do to determine whether the B.T. is still working correctly, short of buying another one to check whether the results are the same?

Thanks in advance for your collective wisdom.

I have a battery tender of newer vintage, I guess, only one light that is Red for Charge and Green for Storage. I'm in Eastern NC, where it has been pretty cold and wet of late.

On October 28 I had major surgery. Came home on November 03 I left the hospital. A few days later I pulled the BT from the FJR and put it on the car becasue I didn't expect to drive it soon. Forgot to put it back on the FJR when I started driving again. Yesterday, December 27 I found this out when I thought I was going for a ride. :angry: Instruments worked, starter cranked it two, maybe three "grunts" and I quit. '04 FJR, original battery.

NO BT for about fifty days in my case and not enough juice to light the engine. When I put the BT back on I had Green light in less than four hours. What bothered me was that the during the Charge cycle instead of a steady Red which I"m used to, it flickered and at times showed almost orange, sometimes a non-color. Made me wonder about the BT. But Green later, and it started easily today.

 

[mtnhigh]

Turn the lights on with the B.T. hooked up and see if the status lights go from green to red. If it does then all your batteries don't need the charge right now, and your good to go. The tender is working propery. That's my test.

 

[FJRay]

Turn the lights on with the B.T. hooked up and see if the status lights go from green to red. If it does then all your batteries don't need the charge right now, and your good to go. The tender is working propery. That's my test.

+ 1 on the test method. Thats how I check mine and I have 5 f them. I did have one fail after I ran over it with a truck.

 

[Zorlac]

"an unheated garage, at about +8 F"

Batteries self discharge more slowly and last longer in the cold, they're less chemically active hence the lower cranking power, kinda in a hibernation of sorts. Heat discharges & kills them much worse than the cold.

"The red and green lights on the B.T. still work, and go almost immediately from red to green. Battery voltages measured at the standard SAE pigtail showed from 12.39 volts to about 13.2 volts"

13.2V seems fine, 12.39V unloaded is low but still serviceable.

 

[mcatrophy]

I have a Battery Tender Plus ... at about +8 F...

It may well be too cold for the Battery Tender to work correctly, it would be unusual for domestic electronic devices to be specified to work below freezing.

I've looked at the manual, but that only specifies a maximum temperature.

Try running the BT in a warmer area with extended leads to the battery, [WARNING] but be aware it won't charge the battery properly [/WARNING] because it has temperature compensation to cope with the different battery characteristics at different temperatures.

Or take one of the batteries out of a vehicle, take it indoors, give it 24 hours to reach the indoor ambient, and try charging it.

 

[3dogs]

At the risk of stating the obvious, you could connect a voltmeter to the battery (or SAE connector) and check the battery voltage with the Battery Tender not connected. Now connect the BT and see if the voltage goes up. Usually when a BT is first connected charging voltage should be around 14 volts then slowly drop to around 13.2 as the battery becomes charged.

 

[charismaticmegafauna]

What he ^^^^ said.

I recently got a M.F. (factory fill) AGM battery (not for FJR, tho) and the paperwork with it stated: "Check voltage every 3 months." I find that works for me -- when my bikes sit for any length of time I just check the voltage; if it's OK, it's OK -- if not, they get charged 'till it is.

100% = 12.8V ~ 13.0V.

BTW, the FSM gives a rather elaborate explanation for battery charging -- using both a variable voltage charger and a constant voltage charger (it fails to mention the use of a maintainer...). The FSM often encourages the tech to 'check the voltage'.

It also warns: "The MF battery should be charged as explained..." And, "If the battery is overcharged, the electrolyte level will drop considerably. (thereby shortening battery life and performance) Therefore, take special care when charging the battery."

I'm not so sure hooking-up a small charger and leaving it on is such a good thing...?

 

[ionbeam]

...It also warns: "The MF battery should be charged as explained..." And, "If the battery is overcharged, the electrolyte level will drop considerably. (thereby shortening battery life and performance) Therefore, take special care when charging the battery."I'm not so sure hooking-up a small charger and leaving it on is such a good thing...?

You need to be sure you have a real battery tender or smart charger which offers a 'float, storage, or maintenance charge' mode. Once these types of battery chargers have the battery fully charged they shut off all charging current to the battery and monitor battery voltage. If battery voltage drops below a certain level (different companies use different levels) the tender turns on and tops off the battery, then returns to the monitor mode. The older, dumb, trickle chargers would simply switch down to a low, but continuous charging current for all of eternity or until all the electrolyte boils out of the battery :glare: Choose your charger wisely and there will be no problem leaving a true tender on 100% of the time.

 

[BwanaDik]

Isn't there also a difference between a tender used for a "standard" lead acid battery and one for a gel cell? I thought the gel cell needed a higher voltage? Possibly an older design tender with a newer design battery?

 

[Crash Cash]

Isn't there also a difference between a tender used for a "standard" lead acid battery and one for a gel cell? I thought the gel cell needed a higher voltage? Possibly an older design tender with a newer design battery?

Yup, that's the difference between the Battery Tender and the Battery Tender Plus. See question #13 at the Deltran FAQ

 

[Crash Cash]

I have a Battery Tender Plus brand charger that is about 12 years old

Are you sure it's a Plus? Deltran didn't make the Plus model until about 9 years ago according to their FAQ.

 

[MT home]

I have a Battery Tender Plus brand charger that is about 12 years old

Are you sure it's a Plus? Deltran didn't make the Plus model until about 9 years ago according to their FAQ.

Yep, Battery Tender Plus, per its labeling. I guess that it is only 10 years old (Christmas gift,IIRC) now that I think more carefully about it. It is stored in the motorcycle garage, about a block and a half from my house. I have to beg electrons via an extension cord from the neighbor's apartment to have power to the garage, so I don't leave things plugged in any longer than necessary. (Don't ask about why the garage at home isn't available/used for the motorcycles.)

The suggestions that the B.T. might be too cold to operate correctly had not occurred to me, but I think that I've used it in temps at least this cold in previous winters. I'll try warming it up to house temps (up to 60 or 62 F, you folks in the South) before the next use. The suggestion of turning on the ignition and headlight [on everything except the FJR] and seeing whether that triggers the charging cycle is good, and something that I should have thought of myself.