Battery Loosing Voltage [Archive] - Snowmobile World : Your #1 Snowmobile Forum

: Battery Loosing Voltage

01-10-2005, 08:13 AM
Well, after my first ride on my new 600 Sdi, I tested the battery voltage and it seemed a little low like 12.2 volts. But I didn't check before the ride, so I thought it my have dropped just sitting waiting for the first snow.

So, I charged it up, took a charge fine, and tested at 12.8. Right where it should be. Fired up the sled and put the meter back on the battery and it showed a little over 13. Increased the rpm's some, and it went up a little more to 13.5.

so, my logic figured that it was obviously putting juice to the battery and that at higher RPM's it should probably be charging fine.

Put 350 km on the sled over this weekend not really worrying about it, and everything ran perfectly. Absolutely love this sled. However just for fun after the ride I put the meter on and got a reading of 11.8. Way too low for my liking. Seems to me that in a few hundred more km, I'll have a dead battery and dead sled.

Most of the 350km was pretty fast running, so its not like I was not giving it a good chance to charge.

Not making sense to me. If the battery was bad, I'm surprised it took a good charge at home on my charger, and held 12.8 v for over a week of sitting.
If the sled wasn't charging, why am I picking up higher volts at the battery terminals when its running?

Any suggestions or experience with this type of problem.


01-10-2005, 12:30 PM
Hey fishy...How's it going up there?

Sounds like your battery is just bad. Donna's did the same thing. We ran the battery low over the first summer by leaving the tether attached. When you leave the tether attached, it draws a very small amount of voltage for the MPEM to read the chip. Once it sat there for a month or whatever at the lower voltage it never would hold a charge well enough for the mag to keep it charged, but my Snap-On charger would charge it right up. We limped thru the second season by keeping it charged with the Snap-On then bought a battery this year. I'm told it's hard on the stator if you let the battery get low. If I were you I would load check the battery to check the condition and replace if necessary.


01-10-2005, 02:26 PM
Things are good up here, other than the lack of snow. I knew I'd screw up winter by getting a new sled.

thanks for the info. I guess I'll stop leaving the teather attached. Never thought of that. I hope thats all it is, but still makes me wonder why I can start with a full charge and have it go down while riding. You would think the sled would give off enough voltage to atleast keep the battery from getting low.

I'll have the battery looked at.


paul yarek
01-10-2005, 08:52 PM
when the sled is not running is that when you say the battery should have more then 12 volts? the sled should charge around 13.8 volts and when the battery just sitting without a charger hooked to it you should see not much more then 12 volts.

01-11-2005, 09:36 AM
Actually, I disagree Paul. A fully charged 12volt battery should give you a reading for 12.7-12.8 volts.
12 volt reading is only about 50% charge in the battery.

Unless these batteries are something special, but I'm pretty sure they aren't.


paul yarek
01-11-2005, 07:19 PM
Originally posted by paul yarek+Jan 10 2005, 09:14 PM-->Fishie,
when the battery just sitting without a charger hooked to it you should see not much more then 12 volts.
like i said not much over 12 volts and okay you say 12.7 agreed. :cool:

<!--QuoteBegin-FishHog@Jan 11 2005, 09:58 AM
Unless these batteries are something special, but I&#39;m pretty sure they aren&#39;t.

i don&#39;t exactly know what you said there :confused:

i&#39;m going out to the barn and hook up my battery tester for my own curiosity now. :blush:

paul yarek
01-11-2005, 08:12 PM
i just tested it at 12.5

01-12-2005, 08:09 AM
Sorry, wasn&#39;t trying to confuse you. Just a difference of opinion in what is a little over 12. Those decimals actually mean quite a bit on a 12 volt battery. For example.

12.7 = 100% charge
12.5 = 90%
12.42 = 80%
12.32 = 70%
12.20 = 60%
12.06 = 50%
11.90 = 40%
11.75 = 30%
11.58 = 20%
11.31 = 10%
10.5 is a dead battery

so your sitting fine at 90%. If the battery is a year old, and not just off a charger, I wouldn&#39;t expect much more. Mine however starts off at 100% and after 350 km of riding, drops to about 35% charge.

so if I ride 500 -550 km I&#39;m going to have a dead battery and a dead sled.

Can-do has it now, I&#39;m calling them today, hopefully they found a problem, as I want to pick it up on my way back from Hamilton tomorrow. Was hoping to ride this weekend, but the weather doesn&#39;t look good.


paul yarek
01-12-2005, 12:11 PM
a good time for repairs when there is no snow. i just got the rings updated at Can Do. don&#39;t steal my teddy bears when you are there.

01-12-2005, 01:22 PM
Hey Fishy,

Idooski is right concerning the parasitic drain having the DESS plugged in. Your science is sound except for the influence temperature has on the electrolyte inside your battery. Ideally the specific gravity of electrolyte is between 1.260 and 1.270 (depending on the accuracy of your hydrometer) @ 85 degrees F. Your efficiency decreases with temperature so charging will warm the battery up to ideal in a warm garage but charging (from the sled&#39;s system) outside will barely warm a cold battery. On many sealed batteries there is a high amperage "Wake Up" Charge required to heat the plates enough to melt the protective sealer on the internal plates. This is why sealed (maintenance free) batteries have shelf life. Get the battery warm with a higher amperage charger then see if it will keep a good state of charge. If not, can you say warranty.

01-12-2005, 01:38 PM
I don&#39;t want to make a big deal of this, but I think it might be very important to the life of your engine to keep your battery in good health. The more charging the mag has to do, the more heat that is created.

01-12-2005, 04:32 PM
Well, dealer said they replaced the battery and the voltage regulator, although they didn&#39;t test bad.

I hope that fixes it, but I suspect I&#39;m going to have the same problem on the next ride. Maybe not, but we will see.

Thanks for the help guys.


01-12-2005, 10:24 PM
If this still happens, can you get one of those automotive type volt meters and temporarily instal so you can watch voltage as you ride??

I had an old Yamaha RD400 2stoker bike that as it got heated up, the voltage from the mag would fall off. This is how I figured that out. Had to put in a new stator. Heat creates resistance, and as the stator would heat up, the voltage would go away.