Sudden Battery Death and Vibrations

[Mouse]

During the first 18 months or so of the Kubota Z482 bikes life I went through one car sized battery every 2 - 3 months, some times sooner. Come to think of it the old German V Twin ate them, but that had starting issues and the VW powered bike went through about three batteries in the year it was on the road which was a bit excessive. I didn't think much of it as I was using second hand batteries from the local friendly car breakers for about £15 each and assumed I had a string of bad luck batteries with an element of karma for being tight and not buying new. That was until one day the men in the breakers cornered me and demanded to know what I was doing with the batteries as the last two they saved for me were really good ones that they had saved especially for me and I was claiming they had each lasted about 4 weeks.
So after a chat where they inferred I was running a scam as well as not accusing them of selling me rubbish I went home and read up a bit on lead acid batteries and discovered that they are sensitive to vibrations and what with being bolted down solidly to the frame of a diesel bike thought that this might be my problem. It could have been the charging system but I am careful with charging voltage and even have a handle bar mounted voltmeter to keep an eye on things so have ruled out a bad charging circuit. I have also tended to build my bikes with the battery box bolted to the frame and on the current bike it is strapped to the top of the gearbox that is in turn solidly bolted to the engine which can only be the worst combination for vibration to be transferred to the battery. Also thinking about the whole battery mounting problem I was reminded that the BMW R series has the battery box mounted on rubber spools and most jap bikes I've worked on have some sort of rubber padding inside the battery tray.
So early last spring I made my own rubber mounted battery tray using cotton reel type mounting blocks to isolate the vibrations from the engine and bought it a new (second hand) battery and waited to see how long it would last before making a post here about it. So far the battery has lasted almost a whole year including into the winter months with the cold giving the most demanding starting conditions. It is still giving the same cranking performance I would expect of a battery in good condition after all this time so I can only think it was the vibrations that were prematurely destroying the batteries.

To summarise: My bike used to kill a battery every 4 to 10 weeks when it was strapped solidly to the engine / frame however now I've rubber mounted the battery tray the same (2nd hand) battery has lasted a whole year and is not showing any sign of giving soon.

[Tetronator]

Good to know, figuring out a good battery rig is something to be aware of on my build then...

[coachgeo]

Mucho thanx for the update on this!!!

[Stuart]

Another essential bit of info that all diesel bike builders should factor in

[henneberg]

thanx for info.
I wonder if the gel type are as sensitive to vibrations as the "solid cell" type lead batteries

[Tetronator]

You could use capacitors as a battery substitute, those are less prone to vibrations.

https://www.youtube.com/watch?v=z3x_kYq3mHM

[coachgeo]

You could use capacitors as a battery substitute, those are less prone to vibrations.

https://www.youtube.com/watch?v=z3x_kYq3mHM

If my understanding is right they are also fast to discharge.... aka if your bike does not start on first or second crank your capacitors will be out of juice.

[Tetronator]

True, supplement with a small Lithium battery perhaps.

Having a kickstarter helps too.

[coachgeo]

True, supplement with a small Lithium battery perhaps.

Having a kickstarter helps too.

That's the only down side of CVT drive

[UAofE]

That's the only down side of CVT drive

Besides no fun of shifting through the gears.

Use an AGM battery, they are much sturdier to vibration than wet cell car batteries.