Reliable 6 volt battery

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Reliable 6 volt battery


Post by kaptekarev » Wed Mar 05, 2008 2:15 pm

Description: Has anyone found a 6 volt battery

Post by kaptekarev on Mar 26, 2007, 10:18pm

Has anyone found a 6 volt battery? My year old Harley battery is suddenly dead and instead of just replacing it, I'm trying to find a better solution. I searched this forum and didn't really find any good options, so I figured I'd pose the question again.

Has anyone tried to use a 12V battery and step the voltage down to 6V? Does anyone know how many amps are drawn, in a 6 volt system? Besides voltage and current what are the other specs on a battery?

Post by Skip on Mar 27, 2007, 2:18am

Post by pantony on Mar 28, 2007, 12:18am

I worked for a battery company for ten years or so, lead acid and sealed batteries. Your battery wasn't "suddenly Dead" it was down on it's state of charge before you put it away, then it self-discharged down to where it sulphated and it was then junk. The 6 volt batteries that they now get for harleys are all made in asia. Thanks to good old uncle sams regulations there aren't too many of them made here anymore. Yuasa used to make the best when they were made in japan but now they are even contracting that out to Taiwan. The new battery I have is from Harley and they get them from there too. OI would sugest you watch the overflow tube fitting hitting the top of the oil tank. Some have glued that shut and drilled vent holes in each cap. I would stay away from sealed 6 volts as they can't take the heat of the oil tanks and are even rated for something like 140 degrees and that doesn't sit well in a 200 degree oil tank. No you can't "step" the 12 voly batery down to 6 volts, you only need 3 cells (2 volts per cell) why would you buy something you don't need. Your spec question has to address what bike you have and what you have on it, They are all diffrent, and what generator you have in the bike. Basically the 6 volt system works pretty good if you don't alter anything. I read a lot of postes from guys that change a lot and then write about all the problems they have a month or so later. Next time you store your bike make sure the battery is 1), charged 2), kept in a cold place (self discharges slower) 3) disconnected from the bike (also self discharges slower) 4) washed off and dry (trace current can self discharge around the outside of a acid-damp battery) 5), clean the posts and connection terminals on the wires, I can't stress that enough, bad connections will bring resistance and poor performance, and finally get a small 6 volt charger, I made one from a kids toy electric car that had a 6 volt sealed battery in it, 300 milli-amps; Perfect! Plug that in over the winter and your two wheeled pride and joy will be waiting patiently for you to give her the spring time kick.

Post by 108 on Mar 28, 2007, 1:00am

Pantony is right on, Just dont let get dead! I have 3 summers on a Harley dealer 6volt battery. I keep it above 6.2 all winter by checking the voltage every month or so and charge it with an programmable automatic charger we use for or electric R/C airplanes. It charges in pulses and decreases the rate as it nears 100%. Years ago I just used a $5 1 amp. trickle charger. Ive only had one battery go bad on me in 20 years on a '48 FL with a three-brush generator and it broke "open circuit" somewhere inside.

Post by panzr4ever on Mar 28, 2007, 2:19am

kaptekarev...there is an ebay seller listed as the greatrandolfo. he has a 6 volt gel battery for HDs. Looks to be the right dimensions. You might type him. He is good about answering questions.

Post by 1950bobber on Mar 28, 2007, 2:26am

"kaptekarev...there is an ebay seller listed as the greatrandol"

Yes, Yes I agree!!! I have talked to this seller a couple of times...purchased his 12 volt sealed battery for my Pan....he is everything that is good being said about him...I would WHOLEHEARTEDLY AGREE...Contact him!

Jim in Seattle "1950 Bobber"

Post by Fixman on Mar 28, 2007, 12:15pm

Please listen to Pantony about 6 volt sealed lead acid batteries. I have tried two of them from different places (one from greatrandolfo), and neither lasted more than a few months. They simply can't take the heat. The HD batteries have done well for me, lasting two or more years.


Post by Sidecar on Mar 28, 2007, 2:06pm

No easy way to properly step down a 12 volt battery to 6 volt. You won't be able to charge it properly either.

I repaired batteries for over 10 years. A dead sulphated battery does not mean its junk. There are more factors that determine if it's junk or not. They can be "Hot" charged and work perfectly for many more years. I don't recommend doing this yourself though. It can explode on you even if you are careful. I repaired hundreds of "dead sulphated cells" while I was working for Gould/GNB/Crown. As a matter of fact, I hot charge a battery almost every spring on a 1986 Honda 4 wheeler that I own. Every third year I replace the battery dead or not though.

I run a 12 volt sealed lead acid in my horseshoe oil tank. I'm not sure, but I think this will be the third season for it. I have it out right now and am thinking about changing it though because of the heat it sees.

My suggestion would be for you to charge your battery every month or so when not riding the bike.

Post by RussW on Mar 28, 2007, 5:20pm

There can surely be manufacturing quality issues with the Harley brand batteries which are not related to how you care for them. I went through 3 batteries in a 5 month period about four years ago. Two of them just dropped to a 4V output in a few weeks, the third again would only put out 4V unless you pressed down on the (+) terminal, then it would jump to 6V. My local dealer replaced the first bad one no charge, then refunded my money for the second one. I went to a dealer a couple hundred mile away for the third, assumming my local guy had a "bad batch". When this one failed, that dealer refunded my money also. You KNOW a Harley dealer is not going to give you cash back on a battery unless he knows it's faulty. (Even then.......) I now use an AGM 12A/H sealed unit, get a couple seasons out of one.

Post by Sidecar on Mar 28, 2007, 6:15pm

The old harley dealer around here did not sell H-D batteries. They got them from a local source and swore up and down that they were better than the "factory" batteries. The dealership has changed owners and is in a brand new building. I don't know what kind of batteries they supply at the new place.

Post by Fixman on Mar 28, 2007, 7:27pm

RussW, can you give me some details about the 6 volt AGM battery you are using? I know that the SLA's don't work for me, but I would like to try an AGM. Where did you get it? what are the dimensions? Thanks,


Post by RussW on Mar 28, 2007, 11:33pm

This battery is 6"x2"x3.75". I was told by a sales rep at another battery company that MK was a better made battery than the brand they sold.
I have taken two of these batteries and taped them together to form a 6"x4"x3.75" battery pack. Fits neatly in the horseshoe tank, once you shim from the bottom for the shorter height. I then ground each battery with it's own ground wire, and run the (+) leads from each battery to the two sides of a double throw toggle switch. This allows me to switch from one battery to the other with the throw of the switch (center lead of switch to ignition switch, left lead to one battery and right lead to the other). I alternate which battery I use every couple weeks to make sure they both stay charged. When the day comes one dies, just flip the switch and ride on.
You must have a good electronic voltage regulator which will not cook the 12 amp battery, I use a Cycle Electric.
They batteries stay in the bike out in the garage with NO charging for the winter months, just turn the key in the spring and they fire right up. I know thats just not right to do, but the last one that failed lasted into the third riding season that way.

Post by Fixman on Mar 29, 2007, 10:31am

Thanks RussW. I guess that SLA and AGM are the same thing since the MK battery shown on the site you gave us says "Sealed Lead Acid" on it, while the narrative says AGM. I do have a good electronic regulator, but the SLA's aren't happy in my bike.


Post by Skip on Mar 29, 2007, 12:22pm

let me ask you battery experts a question...first no one in my area load tests 6 volt batteries...with a meter it registers 6.23 to 6.33 volts...kept checking it through the winter and at one point charged it for a whole day before the charger shut off...never boiled help in my attempts to start this POS...I put my 1 amp 6 volt trickle charger on less than 15 minutes it was it a battery problem or charger problem...was it up enough not to need a charger put to it...never had this type of problem before...voltage went to 6.88 by the way...battery will be 2 years old in September...thanks for the interest....Skip

Harley battery if needed to know...S

Post by 108 on Mar 29, 2007, 9:20pm

AGM means "absorbant glass mat", they have like a thick paper towel soaked in acid solution pressed between the plates. Performs like wet battery but wont spill.

Post by 48moon on Apr 2, 2007, 1:48am

Check out this link. ... icle&k=327

Good luck,

Post by pantony on Apr 9, 2007, 2:04am

108; you correct and I'd add that the "paper towel is really made of fiberglass. Skip your battery is fully charged, batteries will boil (or really called gassing) at 80% charge and up. Your battery was fully charged and it don't want no more! You can get a load tester from Associated (they make them for Snap-On) every fork-lift road mechanic I ever knew had one in his van and they will put a load on any voltage. This handy thing just has a heating element in it to supply resistance so voltage really doesn't matter. Just hook up the leads and hit the load switch and watch the readings and pull the caps out to see if you have a shorted cell, it will boil on a load if one is shorted.

Post by pantony on Apr 9, 2007, 2:06am

Follow this link and click on analog load testers

Post by pantony on Apr 9, 2007, 2:09am

48moon; I had an Eagle-Picher sealed battery in an old battery case just like the pic you see in that link, it lasted one trip to the Harley dealer, about a 10 minuite ride. Eagle-Picher batterys are about the least quality sealed battery you can buy, they buy only the cheapest

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