Hi all.
I have a problem with the charging system on my XTZ660 Tenere, the battery has gone dead a few times now after about 1 week from being fully charged.
So I decided to get the multimeter out to do some tests.

The DC Voltage output is 12.20V from idle to 3000 rpm, If I rev it up to 5000 rpm it increases to about 12.70V then drops to 12.30V again. At 3500 rpm it slowly increases to around 13.50V, if I rev it up again to 4000 - 5000 rpm it drops to around 12.30V again.
The manual tells me it should be 14V at 5000 rpm, so I guess some thing is wrong. right?

I have done more tests, such as having the battery load tested at a bettery shop..... it checked out fine, it is a good battery too, a DEKA power sports AGM.

Had the stator tested and it checked out fine, all 3 phases putting out 0.3 ohms.

I checked the AC output of the stator too, unfortunately I did this wrong by not unplugging the connection to the regulator/rectifier, but my readings were 10 - 11 volts at 5000 rpm. (I realized this was wrong after i had removed the stator, so i can't check the proper way just yet).
I also tried a backyard test by connecting wires from a 100 w spot light in to all three phases, it lit up bright and even across all three phases.

All wire plugs/connections have been checked and appear to be in good condition.

So after all this i bought a new regulator/rectifier, thinking this must be the problem. I got an Electrex one.
I plugged that in, and nothing changed.

I have now taken the the stator out too have a look for any signs of being burnt out, it looks fine.

Anybody have any ideas as to what the problem is??,
i'm stumped cause everything has checked out in good order.

thanks

When I had a XTZ 660 the positive battery terminal would foul for the lack of a better word when I was riding it through rough and tough stuff. I would have to unscrew it clean it up and hey presto I had a working battery again.

Not saying yours is the same but beyond that had you checked and cleaned all the earth points ?

I had similar symptoms with my 3TB, and it was the reg/rec. The way it increases voltage up to a point and then drops back down again suggests that it is the regulation of the voltage that is the problem, not the generator itself. I know you have fitted a new one, but could you borrow a known good one just to check? It certainly sounds like a reg/rec to me. And they are a known weak point with thse bikes.

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2006 XT660R daily ride, 1994 XT600E about to be reborn, Blog: http://goingfastgettingnowhere.blogspot.com/