Seen this a few times - remove the neg terminal - connect a test light between the off terminal and the battery - then un plug the power to the voltage regulator

it acts like a trunk light back in the day that did not turn off - if the light goes off replace the regulator - one guy said he would just move the power to key on only

100 miles out he found out that was not a real good idea at night in the rain

 

Yea my battery box is on the right side roll bar and if you hold while the bikes running it feels like a jack hammer but its an AGM they say they can handle it but how much is to much ya know I often wondered if its getting to much vibration and damaging the battery? I have seen guys re-locate the battery under the seat its a DEKA it got high ratings and yes back in the day we never used tenders either got about 3 years but I guess these new bikes need them with all the crap on them now they draw constantly

 

Checked for that no drains when shes off shes off battery is a DEKA

 

Funny you mentioned that only thing left in my mind that damn box is welded right on the roll bar and it vibrates like a jack hammer but AGM they claim can handle that im starting to wonder how true is that and how much is to much mine is excessive its so bad the left side saddle bag bracket under the bag that holds the pipe has broken 3 times as well as my cross over pipe have cracked several times as well I have gone to 2 into one not big on the look but had no choice bike runs good though

 

Its the battery,and the simple truth, most manufacturers are under gel filling them to start with, and too much time on the tender when not needed, is just causing the battery to dry cells faster. Hence the reason that most will only warrenty the power sport type batteries for a year now at most, and some only doing 6 month warranties instead.

So difference between agm and wet cell battery, is the agm uses the water-acid solution in a gel form in the glass mats so it does not splash, but when the battery is always being charged via the tender too much, this causes the gel to dry up faster (water in the gel cell to steam out)l.



Yes, you can pull the fill caps to add a touch of distilled water to re-moisten the gel if needed to replace the distilled water that has steamed out. Hence pop the fill caps off, and only add enough distilled water to the each cell that it will just have thin layer of water on top of the gel in each cell only, then reinstall the fill caps

Do not fill the battery with distilled water to the level that you would on a wet cell battery, since want to add just enough distilled water that the gel will absorb all the free distilled water added back in the gel in the end. Hence no loose water in the end to splash, nor just sitting in the battery that was not absord back into the gel to freeze up as well

As for tender on the Evo, since it does not draw voltage for the most part when the bike its shut off, then reserve the tender use to only every few months to de sulfate the battery alone , and top if off during storage as needed with it on the tender for about half a day each time at most. Hence problem with the tenders, is they are mostly for car batteries, so try to hold the battery at around 13.2 or more volts, while the power sports batteries tend to top out around 12.8'ish volts, so lower hold voltages that some tenders cause the dry cells problems in the first place. So again, limit the tender time on the battery, and only use a few times a year, to just de-sulfate the battery as needed alone.

For batteries that seem to last longer when it comes to the power sport batteries, might want to look into the Yuasa batteries, since they tend to be gel filled fully/correctly from the start, and tend to last longer due to such; so long as you are not keeping the tender on the battery, that is just over charging the battery to cause the dry cell in the first place.

Also to point out on the agm batttery, their life span is determined by the life of the lead plates, and again the gel in the mats not drying out from over charging to being with. So can re-moisten the gel to replace the distilled water is steamed out of it that caused it to dry cell, while on the lead plates, the more the battery charges and discharges in cycles, the faster the erosion happens to the plates until the are dissolved away.
Note, if dry cell is left too long, then it makes the problem worse with charges, since the wet cells are still trying to take a charge, while the dry cells are just cooking the lead plates with too much heat instead. So really need to catch the dry cell when you first start to have problem,before it kills the lead plates isntead.

As for how the battery works, when you discharge the battery, the acid in the mix will collect to the lead plate, and when the battery is recharged, the acid on the plate is absorbed back into the solution. Some on the acid is not total absorb back into the solution with the battery fully charge, So these this is where tender de sulfate comes in, to get the last of the acid off the lead plates and back into the solution, so the battery can get back more of it original cold cranking amps.

On a evo that should not be drawing much (fuel injected, and none on carb bike), don't leave the bike on the tender and should be only used for a day say every few months if not riding the bike once a month, to de sulfate only, and a couple of times more if the bike is being stored for the winter . If you have a later bike that has an alarm system that is always drawing down the battery when the bike is off, then may want to use the tender more often if not riding the bike at least weekly, where the battery will top off via the bike being ridden isntead.

This last one I going to throw out there, but on some of the FX bikes, where the battery is located ,can get hit with a lot of engine heat, so HD did limit their voltage regulators to 13.8 volts for max voltage, so the battery was not being cooked by both the engine heat and the battery being charged to the normal 14.2 volts for the Fl bikes that have more pulling down the batteries when running isntead.
Is this the problem, maybe, but does sound like its more of a tender use problem in the first place isntead.

I bring this up since on my evo, had it on the tender as much as possible, and the Duracell agm battery only last about a year. Sam's replaced it with the same Duracell agm battery, but used the tender sparingly to get it to last a little over two year before it stated to have dry cell problems, did the cap pull and distilled water trick since Sams not longer carries them to get another replacement, and that second Duracell battery is now on it 4th year and going to strong still.
With luck, should be able to get at least another year out of the battery until its the lead plates that are gone to really call the battery dead in the end.

 

The only batteries I will use these days are Motobatt, if you can find them, or Yuasa. You get what you pay for. Been left on the side of the road once too often with cheaper brands.
Deka used to be good but I have not used them in quite a few years so cant comment on current products.

When you say your batteries are dying, are you load-testing them on a decent load tester to make sure the battery is the problem? Are you sure it is not a problem in your starter system like burnt solenoid contacts or starter motor brushes that is stopping your bike from cranking when battery gets a bit low on power, as they all do as they age?

 

If you've been using the same tender on all of your batteries, something you might want to check is that is is actually going into maintenance/float mode. I had one that was suppose to drop to 13.2v when it sensed full charge but kept rising to over 15v but the light indicated it was in maintenance.

 

Did all that johnjzjz everything checks good

 

I thought that myself I had the tender junior then I thought lets try another tender same results I am going to agree with you here I ride the bike allot its all basic wiring think im cooking them on top of what KK0G said on vibration all fingers point to that as well even the guys I ride with said "did you ever notice it happens when you have been really twisting it" so I think it may be a combo of both vibration and tender use seems my model is the only bike with the battery box on the roll bar maybe the FL,s had them no other had that maybe im wrong so gona try relocating the battery plenty of room under seat and put a tender on it here and there maybe once a month and we will see what happens I have done everything else a guy could do on this thing ALL test new batt cables checked for good grounds ect did everything

 

Be Very Careful with Yuasa... By Experience under Harsh Conditions..Yuasa batteries are Made in 3 different Places... Says Righ ton 'em... Made in USA, last a Couple years...about on par with DEKKA.. Made in Japan?? Maybe a Year... Made in China??? Or was it Tailand?? I forget..We could rarely get more than a Couple Trips to Track!!!
Check this Yerself!!! Not on the Internet!!!