I’ve got an annoying battery issue which I thought I had solved.

Posted by jgcoutts on Sep 02, 2023; 1:03am
URL: http://vintage-and-classic-hondas.81.s1.nabble.com/I-ve-got-an-annoying-battery-issue-which-I-thought-I-had-solved-tp4064823.html

During my C115 (identical electrics to the C110 with winkers) restoration I installed a new battery which a couple weeks later I discovered had 5.8volts next to no amps.  I finished the restoration and installed a new battery with a cutoff switch on the negative side used every time the bike is parked and thinking it must have been some drain on the battery when ignition off.

That has worked great(or so it seemed) for a couple months but having left the bike sit for a week I discovered it has happened again. Running the headlight was barely there and then not and the horn was pathetic unless reving and then not as well. Winkers are fine, as was brake light, warning lights and taillight.

The winkers and brake light run off the secondary’s AC rectified the the DC is regulated through the battery.  The horn, headlights, taillight and speedo light all run off the the secondary’s AC output.

Has anyone experienced this and know what is killing my batteries?

I have replaced the selenium rectifier with a new silicon one, converted all lights, except the taillight and speedo light, to LED(DC for winkers (with an electronic flasher), brake and warning lights and AC/DC for headlight) but that shouldn’t and can’t be the cause because this first happened with incandescent.