Charging question

[cperky]

I have a 1994 honda trx250. With a new battery is will start using electric start but after a few uses I have to kick start is every time. Does it have an alternater like a car that should keep the battery charged?

Additional info: I can use my spot sprayer when the 4 wheeler is running so does this mean the alternater(if it has one) is working? I hook the sprayer directly to the battery posts with alligator clips.

Thanks,
Chris

 

[RonMar]

Got a volt meter? You need one to determine what the issue is. When running, you should get 14.5VDC +/- 0.5 VDC at the battery terminals. 15V and above will eventually boil off the electrolyte. Below 14V and the battery will not get a full charge. I am not sure of your exact configuration, but I would doubt you have a standalone alternator. The fact that it still has a kick starter makes me think this, and would indicate a low charge output system. What you most likley have are charge windings built into the stator assembly along with the windings that provides the electrical current for the CDI ignition module. These charge windings feed to a rectifyer/voltage regulator which delivers the 14.5VDC into the electrical system at the battery. This type system typically has lower electrical output due to the use of the fixed magnets on the rotor. Basically used to give some basic electrics to what was initially a non-electric design.

Depending on the rated charge system output, it might not be very happy with an add-on spray pump. IE: it is not designed to make up for that much electric current draw and the volt regulator is being given a real workout trying to keep up. It sees the spray pump as a near electrical short/bottomless pit that it can't fill with current. It could be that the sprayer work has limited the charge systems output capacity(damaged diodes in the rectifyer) and has reduced the systems ability to put current back into the battery after a engine startup. How long has the engine run between starts, or how long are these 5 starts spread over?

 

[cperky]

Ron,
Thanks for the input. The year on the op was incorrect it is actually a 1984 model. I will check the voltage output with a meter. The unit is only used a few times a year so there could be a week or two between starts. I'll post the readings later in the week when I get a chance to check it out. Do you know where the diodes are located?

Thanks
Chris

 

[RonMar]

Ron,
Thanks for the input. The year on the op was incorrect it is actually a 1984 model. I will check the voltage output with a meter. The unit is only used a few times a year so there could be a week or two between starts. I'll post the readings later in the week when I get a chance to check it out. Do you know where the diodes are located?

Thanks
Chris

The rectifyer and regulator are most likley all in a single sealed/potted unit in a aluminum heat sinc case that is mounted to the frame rail or a panel up under the tank. Probably with the ignition electronics. 1984 even pushes me more towards a low energy charging system. No one envisioned or marketed any of the ATV add-ons back then, and the manufacturers didn't make an electric systm that would generate much more than just enough energy to run the headlights and trickle charge the battery. You could also have an issue with the battery discharging, also from a wiring issue, which is causing the
failure to start after time. First thing you do when you get to it is measure the battery voltage before you turn anything on. After setting for a week, a fully charged battery should be around 12-12.5V. If the battery is lower than that, and you are getting the 14.5V when running and charging, perhaps something is wrong with the battery, or there is a slow discharge going on and robbing the battery of it's charge.

 

[cperky]

UPDATE!!

I went out and checked the battery with unit not running measured 6.7 volts D.C. then kick started her up and read 8.2 volts D.C. when I rev it up a little the voltage goes up to about 8.9 volts D.C.

Obviously the battery is down. Can I recharge the battery with a car battery charger? if so which setting 2amp or 6amp? I am thinking I need to get the battery up to normal to truely test the charging system, am I correct?

Chris

 

[RonMar]

UPDATE!!

I went out and checked the battery with unit not running measured 6.7 volts D.C. then kick started her up and read 8.2 volts D.C. when I rev it up a little the voltage goes up to about 8.9 volts D.C.

Obviously the battery is down. Can I recharge the battery with a car battery charger? if so which setting 2amp or 6amp? I am thinking I need to get the battery up to normal to truely test the charging system, am I correct?

Chris

You are correct, start with a fully charged battery. Yes, you can use a car battery charger, and the 2 amp setting would be the best unless you have a lower rate, as that is only probably about a 5-7 amp hour battery. Check the electrolyte level before you start charging. At a 2 amp rate, it will probably be charged in about 3 hours, or should be. Don't leave it on overnight, as that is way to high a rate for that size battery long term. After charging for a few hours, disconnect the battery and check the voltage. Then let it set for an hour and see how much it drops. If it sinks below 12V, it probably has internal shorts and needs to be replaced. If it settles in the mid to upper 12V range like it should, put it in your quad and start r up(use kickstart) and see what the charge voltage reaching the battery is then. Using the kickstart with a fully charged battery, it should almost immediatly climb into the mid 14V range at the battery terminals. Once you have that, start turning on the lights and accessories. With all the original equipment electrical loads on, it should not fall below 14V, or if it does, only at idle. Increasing RPM should put it back up over 14V with everything turned on. If it won't do it, you have stator or rectifyer/regulator issues.

Good luck.