85 Big Red Not Charging

[Thundervee]

I charged the battery yesterday and then started the bike, checked it at the terminals with a volt meter and got 12.8v , what is the next thing to check to diagnose this instead of just throwing parts at it? Thanks for the help
http://uploads.tapatalk-cdn.com/20160119/466aaee2f0853826c9c7f4fd539b0781.jpg

[mendoAu]

12.8 should be just fine....what's the problem?

[shovelryder]

Was that measured at dead idle or at a bit of rev? 12.8 sounds low to me.

[Thundervee]

Yeah, 12.8 was at a slight better than dead idol, I know it's not charging because I have to charge the battery every so often after using the bike.

[shovelryder]

Have you tried increasing rpm while looking at the meter?

[Thundervee]

Have you tried increasing rpm while looking at the meter?
Yep. It makes no difference.

[shovelryder]

If try a new battery before tearing into the system. May be shorted plates dragging it down.

[Thundervee]

I'm sure it's not charging, I was just trying to find out the best route to go for diagnosing the charging system, in other words, if I can test the rectifier with a volt meter and does that even play a part in the charging system? This is the second battery that I've put in in the last two years, I charge this one every now and then to keep it going, I bought the bike 2 years ago for 100.00, I put a carb on it and have been using it since.

[Thundervee]

Nevermind, I finally found a thread explaining how to test these things. I search before this post but nothing showed, I Google searched and a thread popped up. Stupid tapatalk[emoji57]

[86125m]

Yes the easiest way to test if the system is charging is to turn on the headlight and see when you rev the engine if the headlight gets brighter as the revs get higher. and bam you now the system is charging. It is more than likely just a bad battery I put one of these brands of batteries in my 200m and it seems to work great. http://www.ebay.com/itm/YTX12-BS-ATV-Battery-for-Honda-250cc-ATC250ES-Big-Red-1987-/291280282395?hash=item43d1a8631b:g:8vUAAOSwYHxWJ1t b&vxp=mtr

[Thundervee]

Ok. Thanks dudes

[wellys88]

whats the rear fenders of

[Thundervee]

They came off a 200. They were on it when I bought it

[ps2fixer]

Since everyone has targeted the battery, I'm going to mention the opposite, possible wiring, stator (charge coil), or maybe a fuse (i'd have to look at the wire diagram). Before replacing the battery with no proof test to make sure you are puting out power from the engine.

Simple/quick test is to remove the battery, turn the lights on. If they come on, your lighting circuit is getting power, and the engine is putting out power. Second test I'd do is check for volatage at the battery terminal hookups (still with the battery out) to make sure the power is reaching the battery. If it is getting power there, then one of two things, bad battery, or the voltage isn't high enough for some reason to actually charge it. From a background in cars, when the battery is charging, it should be getting 13v or more upto around 15v on newer cars. I suspect 3 wheelers would rise to around 13.5v rev'ed up and close to 13v at idle (never tested so numbers can be off a bit).

Let us know the status of the tests I mentioned above and I'll keep an eye out for a reply.

By the way, if you can charge the battery with a battery charger, the 3 wheeler should charge it as well but at a slower rate. Even if the battery has a higher than normal internal drain, if you ride it every day for long enough time to recharge it, it shouldn't die or need to be charged.

Good luck