Interesting Battery Behaviour
 

Last weekend I was on a long ride (2400km, 1500mi). When I got to my destination (about mid point) I started having battery problems.

Battery would appear dead after seconds of the bike not running. Being that I was 1200km from home and no access to this forum we set about trouble shooting. I am aware of the recurring rectifier issues on SHs, we assumed that because once the bike was bump started it ran like a top it must be the battery and nothing to do with the charging system.

Keep in mind that we had no access to the net, I went off past experiences.

I pulled the Yuasa battery (YTX12-BS) and opened the black cap, it appeared to be dry (i learned this morning on this forum that it is GEL not liquid...whoops!), topped it off with water. This appeared to fix everything, finished my ride with no issues whatsoever.

Fast forward one week, the battery is COMPLETELY dead, wont even crank the bike over. I pulled the battery, put it on my charger overnight, got it running today, the problem is that it leaks everywhere, no doubt due to the water boiling over and spilling out.

I am going to purchase a new Yuasa today.

I am looking for an open discussion here, I have read much on these forums today about batteries, including many comments from highly esteemed individuals saying that topping the battery off with water does NOTHING. I can attest, that water in the battery got me home.

Unless of course there is something else wrong.

I appreciate your comments.

I would suggest checking the charging system using the procedures in the manual or knowledgebase on here so at least you will know if there are any issues there before you ruin a new battery. Batteries can go at any time, I have had them crank over the bike fine, shut it off then nothing 5 minutes later. As for adding water to the gel I am no expert but its possible that if the gel had dried out from overcharging it might rejuvenate enough to start the bike.

Adding water certainly can get you home. I have had it rescue me when stranded in Africa. However if your plates are sulfated then the only hope to rescue that battery is a high voltage, low amperage charge. http://www.semarine.com/store/home.php?cat=85

Adding water won't fix the battery though. It just exposes the parts of the plates that might not yet be as sulfated to the electrolytes letting the battery partially work.

edit: and do test your charging system, I wouldn't be surprised if you found a bad R/R

Definately check the charging rate before fitting a new battery. No point ruining a new battery if their is a problem with the R/R.

I have followed every test (charging related that is) in the FSM.

The results:

Current leakage: 0.501mA. (above spec)

Regulated Voltage (engine running, high beam on):
Idle: 13.50V
5k RPM: 13.07V (below spec)

Stator Coil Resistances:
All 3 phases: 0.8ohm (above spec, but equal)

Stator Coil Continuity to ground:
All 3 phases open to ground (good...YAY!)

R/R Wiring Harness tests:
All good per the FSM.

The end result: No real questions answered...everything is bad.

Seriously though....

• Leak down test points to possible short. Wiring harness tests prove the short is not in the charging circuit at least.
• Voltage dropping at RPM must mean that the R/R is toast. Correct?
• Stator phase resistances: Although resistance is a little high, it is equal accross the board. Since the manual states the resistance is at 20C/68F and it was warmer I will assume this is OK.

My theory: The regulator dropped out on me, killing the battery. Luckily a top up with water got me home (even if it did spill everywhere and etch my swingarm/pipe etc).

Sound reasoning? Going forward, replace the rectifier, then get a new battery? What year did the rectifier get fins? Anybody thermally bond a heat sink to a stocker? What year Yamaha rectifier do I need?

My last concern is that additional current leakage, it is very small, regardless it is above spec. As far as I know (good friends with every previous owner) the only electrical modification are flush mount turn signals in the front. I disconnected the R/R (thinking the blown R/R might be shorted) this did not change the leakage number.

Any insight into this one?

Thanks in Advance.

Be aware that the SuperHawk has a Gel Battery for a reason, since it sits at an angle. I would suggest replacing your battery with an OEM spec gel battery.

Batteries on motorcycles generally don't last 1/2 as long as in cars due to the extreme heat, since the battery is usually behind the engine (2 years is average for me on previous bikes). But my VTR is 4 years old next month w/31,000 miles on the original battery. I attribute the long life to the gel battery.

Your R/R is bad. As to if your battery will recover with a good R/R, I don't know.

www.motovoltage.com is the only place that sells R/Rs with a lifetime warranty.

otherwise a R6/R1 5 wire R/R is an option, or an aftermarket Honda one. (one that fits a F3 will fit our bike)

Here is the Yamaha swap: https://www.superhawkforum.com/forum...ad.php?t=14380

check your stator per the test plan at www.motovoltage.com/tech.htm .
If either of the two tests fails, stators bad.
If stators good according to this test plan, the R/R has a fault.

I definitely will be replacing the battery just because this one leaks everywhere now...hey the water got me home so I can't complain too much.

As for the stator tests, I did perform those tests last night. All went well, I measured 0.8ohm on all 3 phases with no short to ground. The 0.8ohm is above Honda's spec, but not above Circuit Burner's. I assume it is in good shape.

Selecting an R/R: Circuit Burner has some nice items there, if I had more time I would probably go that way. I am hoping that today I can find a Yamaha R/R at a local shop (already found a battery). This is the bike I planned to be riding this week while I repair my other, therefore, I am hustling to get it running tip-top.

Oh, the Honda one got fins in 2001, it is better than the earlier one, but some reports still have it failing occasionally. Due to the shape of the stock one, adding a heatsink isn't easy.. I am considering adding a fan to my aftermarket one that is already sinked though.

I had issues there for a while, but I had two items attached to the battery...this is my story... I attached a bmw heated vest attachment to my battery and wired a switch in, all was clean and operable. I noticed that my battery was getting weak so I hardwired a batt tender trickle charger cable to the battery because lately I'm only riding the bike about once every other week, and on my old battery, two weeks was running it down requiring a charge. I had that on the old battery for while and it was also running down charge. I was beginning to think that it was the RR, but was curious and replaced the battery with a new yuasa from my local shop, I let it breath after adding the acid, charged it over night, the bike started right up the next morning. Keep in mind I kept the two items attached...the trickle charger wire with capped connector, and heated vest attachment. Within a couple days my new battery was dead again. i was getting mad, I again was curious, took all the shit off the battery and walla, I haven't hooked it to the charger since I removed those items and no power drain since!!! It's been months and I've riden the bike seldom(I need to ride more!!!)Right now, it will start right up!...

That's my long winded story, so I think anything attached to the battery will contribute to loss of charge, especially mine. Maybe my RR is still bad tho.

THe stock R/R has a current limiter that doesnt allow for very much amperage drain for stuff like heated grips and vests. Your stock R/R is probably still good, but wont handle prolonged drain like that.
If you need one for accessories, I can supply you one thats adjustable current and voltage all in one knob.
Goldwing and touring nuts go for that model since they have all the extra lights and other luxuries.