[gab29]

hello this is my first post and hoping i didn't miss a thread where this was previously covered.



so before this past weekend my 89 twdub would electric start just fine, the lights would not flicker when i rev it up, if it is in neutral with a turn signal on the neutral light would not flicker, everthing was running good. but now after i ride it for the weekend or whatever the battery is drained. per example i had a 100% charge before the weekend. i went to go ride some trails all weekend, performed flawlessly. So today i went to start it the electric start wouldnt work and all of the symptoms described earlier happened. i put the battery back on the noco charger, floater and it indicated being at 50-75%. can anyone tell what is going on? do i need a new rectifier or i dont even know. any help is help.



thank you all for your time i love this forum, found some cool stuff on it.

 

[assquatch20]

If it's not a gel battery, make sure the water levels are right and only top them off with distilled water. A sudden change would indicate either something grounding out badly or the battery is going. It could be worse, but check your battery out fully first.

 

[jpuck]

had this happen once and battery was low on fluid.

 

[n2o2diver]

Check all the battery cables for corrosion. Top up the battery and charge it. If it does it again measure the battery voltage while this bike is running, should be about 13-14 volts. If that is ok then the battery is going bad. If that is not ok then you have a problem with the bikes charging system.

Mine was similar last year and it was the battery.

 

[gab29]

so i forgot to mention that this was a new battery just got it before the weekend trip, charged it full and off we went.



i just checked it now after it has been on the charger. it said its full and everything is working normal. and if anything the battery fluid was above the full/top line.

checked the volts. not started the bike had 12.9 volts and at an idle with pretty much no warm up (dont know if it matters) it had 12.3-12.4.



so is this pretty indicative of the charging system? if so how and what do i need to fix it?

 

[frog13]

Out of curiosity,what brand of battery did you put in?.

 

[retmotor]

Let's back up a bit.



Why did you have to replace your battery?



Is that your bike in your avatar running two headlights? If so, do you know for a fact that running those headlights does not overtax your charging system?

 

[Dubster]

Like n2o2diver said you should get about 13.7 to 14 and a bit with the engine revved up not at idle.

If that is your bike in your avatar with the two headlights and assuming they are both 55 watts that right there is probably your problem.

The charging system on the TW isn't strong enough to run much more than the bike without discharging the battery.



Looks like you posted while I was typing retmoter.I bet that is the problem..my speed on the keyboard leaves a bit to be desired.

 

[flingwing1969]

had this happen once and battery was low on fluid.

When it's low, it's slow to charge and sometimes won't do a complete charge. I have a 24v manlift with four six-volt deep-charge batteries that I charge once a week - it's good for the batteries to keep them up. A couple of weeks ago it charged for eight hours and still was not fully charged, finally completing the charge at 11 hours. The next weekend when I went to do the maintenance charge, I checked and found the level was down on every cell - my bad - I topped each one with distilled water and plugged her it; she was fully charged in an hour and a half and was down half of what it was the week before before I charge it today.

 

[chevy_lifted_4x4]

so i forgot to mention that this was a new battery just got it before the weekend trip, charged it full and off we went.



i just checked it now after it has been on the charger. it said its full and everything is working normal. and if anything the battery fluid was above the full/top line.

checked the volts. not started the bike had 12.9 volts and at an idle with pretty much no warm up (dont know if it matters) it had 12.3-12.4.



so is this pretty indicative of the charging system? if so how and what do i need to fix it?

My 87 had similar problems. I wasn't getting the battery to charge when running at all. I thought I had a bad regulator/rectifier. When I took apart the 4 connection harness, it had a lot of build up/corrosion on the connections. I cleaned them up and it worked great.

- I had another problem recently where my battery wouldn't charge up to 100%. While running I was only getting around 12.8 volts. It took me forever to find out that the brake light switch on the handlebars had come loose. The brake light being on all the time wouldn't allow it charge completely. I fixed the switch and I had about 13.6 volts when running.

 

[retmotor]

Like n2o2diver said you should get about 13.7 to 14 and a bit with the engine revved up not at idle.

If that is your bike in your avatar with the two headlights and assuming they are both 55 watts that right there is probably your problem.

The charging system on the TW isn't strong enough to run much more than the bike without discharging the battery.



Looks like you posted while I was typing retmoter.I bet that is the problem...

Great minds...