Dead Battery Recharging?

[BadlandZ]

I went on vacation for 2 weeks, and like a dumba$$, I left my 2004 Yamaha WR450F ignition switch on.

The battery is totally dead, and I've heard from some guys at work that I can't just throw a standard battery charger on it. What do I need to do?

[5spoke]

I went on vacation for 2 weeks, and like a dumba$$, I left my 2004 Yamaha WR450F ignition switch on.

The battery is totally dead, and I've heard from some guys at work that I can't just throw a standard battery charger on it. What do I need to do?

What you need to do is throw a standard battery charger on it, <font color="black"> but do not over charge it . Or you could KICK START IT and ride around for an hour (dis. the headlight). Standard bat chargers don't monitor voltage and can easily exceed ++16V which will damage your bat.

Use a multi meter and measure the voltage while charging. When the bat gets to 12.5V, without the charger connected, the bat is 50% charged. When the voltage gets to 12.7V, without the charger connected, the battery is fully charged 100%. If the voltage gets above 14V with the charger connected, 'STOP' charging with that charger. Use a trickle charger or put the bat in the bike and ride around a while until it's charged.

[ETP]

I completely drained my WR battery a while back and recharged it for 1/2 hour on a standard 12 volt charger set on the 2 amp (lowest) setting. Worked great, but risked the chance of overheating the battery. It would be safer to buy a charger designed for these small motorcycle batteries.

[comp182]

My old man has ttr 250 that we had the same problem. I will tell you what we did. We Jump started it off the truck (truck turned off) then let it run on a fast idle in the back of the truck for about 35 minutes until we got to the riding area. Worked like a charm.

[Rich_in_Orlando]

Get a Battery Tender battery charger. It is a smart charger and will keep the battery at the optimium level and you don't have to worry about overcharging. The Battery Tender "Junior" is suitable for motorcycles but if you want to use it on your car or boat battery, a regular Battery Tender would be the best bet.

[tallfider]

This also happenned to me a few weeks ago. I just went for a ride for a couple of hours and the battery seemed to have regained its full power. I never recharged it otherwise.

Last week, after crossing a long and deep waterhole, my wr450 seemed to have taking water and it stalled. I had to turn the motor with the stater for a very long time before it got going again. The battery had all the juice it needed. ?

[r_dawg1021]

You let the bike sit on 'fast idle' for 35 minutes. Are you serious? I wouldnt even do that with my street bike that's water cooled much less a dirt bike that takes less than 2 quarts of oil and has no fans. No offense but that's not good advice, ride the bike around don't let it sit running on high idle for 35 minutes ?

[comp182]

R_Dawg, Hate to be a smart ass but if you would have read I said that we let it high Idle in the back of the truck for 35 minutes while we were in route to our riding destination. I usually drive the speed limit of 55 miles an hour. Pretty sure that an air cooled bike in the back of an open truck is getting plenty of air to cool it.

[r_dawg1021]

My bad. It just seemed like the aerodynamics of the truck\cab would push the air around the bed causing it to be out of the open wind. It still not good to let anything idle at a steady RPM for 35 minutes that's all I am saying.