battery drain on a 02 Artic Cat 300 ATV

Bought this ATV at an auction. It had a car battery on the rear rack with a set of jumper cables connected to the main battery. I had let it sit for about a week and the car battery went dead. Did it go dead because it was connected to a dead battery?

I put a 12 volt clearance light in line with the negative cable. It did not light with the ignition switch off or on, but did light when I turned the lights on. Would this indicate that I do not have an electrical problem, other than needing to replace the main battery?
Thank you
SDE

A good battery will go dead over time trying to share it's charge with one with a bad cell. The '02 is old enough to have gone through two-three batteries.

The ATV batteries you get nowdays only last about a year or 2 at the most. I have a 350 and I was changing batteries in it almost every year. I made a larger bracket for the battery and put a lawn mower battery in it. It is going on 3 years now and still going strong and it does not cost 60.00 to 90.00 to replace.

I have the 250 version of that wheeler and even with a new battery if you don't drive it every month or charge it the battery runs down dead enough to short out cells. Its ruined a couple of batteries in the short time I've had it.

Those batteries just go bad if not used regularly. I just get used to pull starting it.

Disconnect your battery and hook up a battery charger as a power source. Make sure everything on your ATV is off. Now turn on the battery charger to see if it shows a current flow on the meter. If it does you have a current draw draining your battery. Now the question is, What's causing the drain...

A light bulb is NOT a very good indicator of low voltage drains. It takes several amps to light a light bulb. Voltages of much less are enough to drain a battery.

Then you have no idea if the car battery or the ATV battery are any good to start with. Unhook them both and slow charge them. IF they will take charge that is half the battle. When/if you get them charged let them set for at least 24 hours unhooked from anything. Check the voltage and see what they still have. It should be well over 12 volts setting under no load. An even better test is a load test then. IF you have a tester than use it if not hook the battery up and start the ATV or even a car. Have your volt meter hooked up while you do this. The voltage should not drop below much below 10 volts while under starting load.

Now if the battery checks out good then put your volt meter in the negative cable side and see if it reads anything with everything shut off. It should not on that older machine. Some newer ones do draw a little bit for some of the electronics but not that older one.

If you show having a drain then unhook things until you find what is causing the drain. It could be a bad voltage regulator to a bad switch. IF you can't find it easily then and do not want to bother to find it, just disconnect the battery when your not using it. If you use it a lot then install a disconnect switch. If you do not then just unhook the battery cable when it is not in use.

I have an old gas power air compressor that has the starter/generator setup on it. It will slowly drain a battery. It only gets used maybe one every other month. I just unhook the cables on it. It is not worth the cost of a new regulator for the little time it gets used.

We get 5-7 years from batteries, and they are cheap ones, from L&M or walmart! But they are in Honda's and we use them regularly.

JDseller,
If your gas powered air compressor is draining the battery I would just put an off-on switch on the wire leading to the "A" terminal on the starter-generator. I think flipping a switch would be easier and less dangerous than unhooking your battery each time and the switch would keep the battery from going dead plus it's cheaper than a regulator. Basically that's all the reverse current relay in the regulator does anyway is just open the circuit if it's adjusted properly and the spring isn't broke or lost its tension. Just my thoughts & 2 cents.

that particular machine is pretty bad at eating voltage regulators. maybe have someone local that knows what to look for check it out.

I have had the ATV battery on the charger (2 amp) for two days now. I am going to leave it on a while longer and then see if it goes dead by itself. The side panels had been removed from the machine and that is why I think there may be an electrical drain, that the P.O. was looking for.
Thank you Everyone
SDE