Automatic Battery Charger question

[Conrad]

There does seem to be some contradictions there.  Why would they need to recharge if they're maintaining a float charge?  Me thinks this will require more investigation, and maybe some actual measuring of what the chargers are doing.

I checked my Tender Jr last night, it's currently maintaining the charge on my sled battery. The LED is green and the voltage was 13.00.

[maxtog]

Hmm.  This battery is only 1 year old, but I noticed it being a bit weak already.  Still always use the Tender Jr. full-time on it.  I left it off the charger for a while, then asked the bike the voltage (ignition, not running), and it showed 12.2V.  That seems a bit low, even with the computer/dash up and the running lights (which are LED withOUT load resistors).  I am not sure how much draw there is in that state, but it is maybe around 20-30W?

Had a 30 min ride, then parked it elsewhere, it sat for a few hours, came back, turned on ignition, and it showed 12.2V again.  It did start OK, just sounds a bit weak still.  Rode home, plugged in the Tender Jr, which goes red for a while, then after a while it is green.  Rinse and repeat.  Every chart I find shows 12.2V at around a 50% charge.  Example: https://footprinthero.com/lead-acid-battery-voltage-charts

It could be the battery is crap (previous one of same brand lasted 3 years).  Just seems so strange, since it is always maintained and it rarely even gets below freezing here.  Could be the Tender Jr. isn't doing its job.  What voltage does YOUR Concours show on the dash when you think it is fully charged and has been off the charger?

[VirginiaJim]

If you are worried about anything on the bike, replace it and stop the stress.  I use a Noco genius 2 charger on the Indian.  Very impressed with it.  Has settings for normal flooded, AGM, and Lithium.  I only charge in the winter.  I don't need it in the summer.  Your charger needs to match the type of battery or you could ruin it long term.  4 years is a good life for a battery thats not in regular usage (charging whilst running).

[maxtog]

Ooops.  Corrected previous post.  This current "Chrome" brand YTX14-BS battery is only ONE YEAR OLD.  It was the previous one (same brand/model) that lasted 3 years.

Performed some additional tests, including using a more sophisticated charger.  It agrees with the state of the battery and acts the same when charging it.  So it isn't the Tender Jr.  I guess it can be explained by the battery just not being deep anymore.  So yeah, I might need a spare battery on hand now.  Still curious what voltage other people show on dash before starting the engine.

[Boomer]

My C14 lives on a tender (Optimate Accumate) and when plugged in the bike shows 13.2V. When I unplug the tender that drops to 12.5V. When the engine is running it shows 14.4V. The battery is a MotoBatt AGM and is now 5 years old. She hadn't been started for 5 weeks and yet she fired right up yesterday.

When the engine is running that 14.4V is running all of the electrics (computers, ignition system, lights, etc.) as well as charging the battery so it needs to be higher because of the higher load.
When she is parked and the tender plugged in, once fully charged the only drain is the batteries internal resistance, so the required voltage to maintain the battery is much lower.
Most tenders will output up to 14V when charging a nearly flat battery but that will drop to 13V once it is fully charged.

If you have one of the more modern "battery maintainers" then those are computerised and will analyse your battery before deciding what to do with it. Those can use a variety of "modes" including discharging, pulse-charging, de-sulphating, and several others. I have a cheap Chinese one of those connected to my C10 and it works just fine.
If your battery feels weak or struggles to start the bike, replace it.

I strongly recommend the MotoBatt AGM. As well as the 5 year old in the C14 I've had one in my C10 for 8 years now and it's still going strong.
You get exactly what you pay for with cheap batteries.

[VirginiaJim]

That Motobatt is what I had.  Very good battery.

[maxtog]

Motobatt MBTX12U ?
https://www.amazon.com/MotoBatt-MBTX12U-Lead_Acid_Battery/dp/B003YMRH70

It has 4 terminals??

[Big Red]

Motobatt MBTX12U ?
https://www.amazon.com/MotoBatt-MBTX12U-Lead_Acid_Battery/dp/B003YMRH70

It has 4 terminals??

4 terminals so that the positive can be on the left or the right when looking at it. Both terminals at either end are just commoned together.

[Rubber_Snake]

4 terminals so that the positive can be on the left or the right when looking at it. Both terminals at either end are just commoned together.

I like that idea.  I have so many farkles on my battery’s positive terminal that it’s tough to fit it all together. 

[Boomer]

Motobatt MBTX12U ?
https://www.amazon.com/MotoBatt-MBTX12U-Lead_Acid_Battery/dp/B003YMRH70
It has 4 terminals??

That's the beastie. Makes it way simpler to attach accessories and chargers.

I have the MB18U in my C10 but I believe that the MBTX20UHD also fits the C10.