Dong Fang DF 250 RTB Bobber Information

[axa]

This one http://www.amazon.com/Shorai-Lithium...A2-BS12+Shorai

I noticed sometime back the DF regulator at idle was over 15v.
I wondered if this was a problem, and now wonder if it contributed to the shorter stock battery life.

Shorai specifically indicates to charge at "13.6V-14.4V".
How long have you had this battery?
Any ill effects so far?
Have you ever measured your magneto output?

[barnone]

Maybe 6 months. No ill effects that I know of and I have not measured the charging volts at higher RPM.

Three year warranty.

[axa]

ok well i jumped the gun and supposed my battery was bad... turns out im getting just 6.5v at the leads, have to test if its the stator or rectifier... im betting its the rectifier.

it never ends for me and this bike...

[axa]

ok well i jumped the gun and supposed my battery was bad... turns out im getting just 6.5v at the leads, have to test if its the stator or rectifier... im betting its the rectifier.

it never ends for me and this bike...

So i dont have a bad stator nor rectifier, with these disconnected from the rest of the bike, each stator coil puts out 15VAC on idle and something way higher, like 30 to 40 VAC with a blip of the throttle. Good.
And the rectifier puts out roughly 12 V on idle, but 13-14 V with some throttle. might be on the low side of things, but that's the problem...

As soon as I hook things back to the bike, keeping the battery disconnected, I immediately see roughly half the DCV on idle, decreasing with increasing rpm.
This is a serious problem...

Just as can be seen with the head light dimming fiasco, this +V node that runs to the fuse and on to the battery, this which is responsible for charging the battery suffers from this reduced voltage.

I suppose the only saving grace is while moving even with the lower VDC, the generator is still providing some current to the circuit so the battery is slower to discharge. And at idle the battery is apparently gaining back some of the lost charge lost while running.
But i say this is not an adequate charge at just around 12 v for that short a time.

There is something seriously wrong with this bikes wiring.
With brief study the manual wiring diagram it doesnt appear to be for this bike. I may be wrong about that but i couldn't make heads or tails of it.

Right now im suspecting there is a poorly placed component, maybe that diode in the box, but im not sure.
But i surmise that this problem not only causes the headlight dim but contributes to premature death of batteries.
I'll find and fix as soon as i find the time
bummer

[ben2go]

If the system is fine until the battery is connected,I'd say the battery has a bad plate(s) in it.Has the battery been tested?Have you cleaned the battery connections and the grounds on the engine/frame.I'm not sure where the ground wire runs to from the battery.

[barnone]

I agree with the bad battery diagnosis. Have the battery tested or get a new battery before you tear into the wiring. My 2010 Chinese battery went bad after a year and the new battery solved the problem.

[axa]

If the system is fine until the battery is connected,I'd say the battery has a bad plate(s) in it.Has the battery been tested?Have you cleaned the battery connections and the grounds on the engine/frame.I'm not sure where the ground wire runs to from the battery.

What I said was the system is fine until connected to the rest of the wiring WITHOUT the battery connected. Bad circuit

[ben2go]

What I said was the system is fine until connected to the rest of the wiring WITHOUT the battery connected. Bad circuit

Ive never tried running a bike without the battery connected.I'd say all the voltage is going away to run the CDI and lights since the battery isn't there to supply the electrical system.

[axa]

I agree with the bad battery diagnosis. Have the battery tested or get a new battery before you tear into the wiring. My 2010 Chinese battery went bad after a year and the new battery solved the problem.

I dont agree.
As mentioned, the generator is fine without the bike wiring.
The battery is fine when charged and used elsewhere.

Anyone care to disconnect their battery and with the bike running and confirm they get a dip in VDC across those terminals when rpms increase??

And even if this is confirmed, your battery might be fine for a while as i mention, it is getting somewhat of a charge at idle even though likely being somewhat drained while running.

Hopefully someone will tests VDC while running with the battery disconnected. (better off someone who didnt do the headlight mod as that may well be the culprit, really cant say at this point)

Or even pull the battery after a long ride, and see if your charge is roughly 12v rather than closer to 13 as it should be

[axa]

Ive never tried running a bike without the battery connected.I'd say all the voltage is going away to run the CDI and lights since the battery isn't there to supply the electrical system.

Vehicles are not designed to supply current (power) from the battery to the electrical system while running.
And rather, current is supplied from the highest potential. In this example, the highest voltage source (assuming there is no other voltage dividers in the circuit)
Just like an alternator in your car, the battery's sole purpose is to start the engine and then generator takes over sourcing current to the system as it has a slightly higher voltage than the battery (the higher potential voltage mentioned above)
And as a reciprocal function if for some reason the battery has a higher voltage, it will be what sources current until it dies down to meet the alternator/generator.
At which the generator takes over and then sources current to all less potential components (including the battery)

But as im saying we have here is a fresh battery first gets reduced to the idle voltage as it has to supply current, and instead of recharging to 13/14v with higher rpms, our bike for some reason reduces voltage with higher rpm, so rather it only gets re/charged to the idle ~12volts, which is not suffice as that is not what a battery should be charged or maintained at....

This evidence leads me to believe all of you are suffering through the same thing (unless the headlight mod some how disconnects the fault and fixed the problem)

Furthermore, even my higher compression engine will start with a battery potential (charge) of just below 12v, as i experimented with yesterday.
So I don't believe anyone can assume they DON'T have this reduced voltage problem but rather your battery is still new and strong.

And I dont yet believe we can assume if you did the headlight mod it relives the problem in the battery node (or rest of bike for that matter)

Ive read charging to an inadequate 12 volts or so will degrade the battery more quickly so we should all be concerned.