TS 150 battery won't hold charge

[Andybantam71]

Hello all, I have a 77 TS150 that the battery is losing charge when running, I am only getting 5 volts at approx. 2000rpm(the battery was charged and checked out ok). The bike has a original style regulator(metal domed cover) so I am thinking it's either the regulator the coil or the commutator? any help or suggestions would be greatly appreciated. Many thanks, Andy.

[DAVID THOMPSON]

charge battery and measure battery and check to see if it drops without being hooked up
to bike

[Andybantam71]

Hi Dave, thanks for your reply. The battery holds a charge when not on the bike, I've got a output from the coil and the dynamo checks out ok. If I turn any lighting on even including the brake light it kills the engine. Regards Andy.

[DAVID THOMPSON]

try a different battery or load test the current one some times battery will show 6 or 12 volts
but will not deliver any current flow

[Andybantam71]

Hi, thanks again but the battery checks out ok. Regards Andy.

[Puffs]

Hi Andy,

I have no experience with the TS150, but I expect the electrics to be similar to the ETZ & other bikes of the era.

If the battery won't hold charge, as is the title of your thread, then either the battery is no good & needs replacing, or, if it only drains when hooked up in the bike, there is something in the bike draining it, even with the ignition & all lights switched off. That shouldn't be. You can confirm with a multimeter if that is the case, and also diagnose where that leak is.

But you also say "I am only getting 5 volts at approx. 2000rpm" and that sounds more like a charge problem. Carbon brushes OK? Check the output of your generator, and verify the rectifier (if it has that?) & regulator work OK. Maybe look in a manual.

Good luck!

[Andybantam71]

Hi, thanks for your reply. I've ordered a coil, regulator, condenser and carbon bushes so I'll see how I get on. Regards Andy.

[Puffs]

Hi Andy,
an ignition coil & condenser are not likely to help in a charge problem, but brushes or the regulator may solve it.
For charge issues, best verify the resistivity of the stator & rotor coils with values from a manual.

But if your battery drains when it is in the bike, with the ignition off, but not if you have disconnected it, you have a leak somewhere. Current flows when & where it shouldn't. Then you need to find that & fix it, because it is probably the cause of your problems. If you have a leak, I doubt if any of the stuff you ordered will help.

Good luck!