Battery issues

[rabn]

Hi All

 

I’m a learner, so apologies if this is 101 stuff…

 

My bike died on the road recently - I'd stopped at traffic lights and when I dropped into 1st gear it cut out and wouldn’t restart. Got breakdown recovery and turned out it was a bad battery (wouldn’t hold charge). I then got a new battery installed by my local garage and all seemed well. However, 5 days later I stopped for a break and couldn’t restart - managed to bump start and get it home and measured the battery which only showed 11.5V. Have recharged and all works fine again, but worried the battery isn’t recharging properly while riding? Since getting the new battery - and unusually - I’ve been riding 3-4 hours per day at VERY slow speeds in bad traffic around town (practicing for my upcoming Mod 2 test) - could this be the cause of the issue - I’m simply not going fast enough to recharge the battery properly? Or does it sound like something wrong with the electrics - a bad stator etc?

 

Many thanks for any pointers…

[billy sugger]

Faulty regulator/rectifier, so bike not charging the battery 

[Mississippi Bullfrog]

Have you got a multimeter? If so set it to reads volts DC and check the voltage on the battery with the engine running. You ought to be getting above 13.5v.

 

Small bikes with small batteries can struggle if you're running slow with lights and indicators on a lot. 

[rabn]

Thanks - charged up the battery last night and it's holding charge @13.3V so looks plenty healthy enough - @Mississippi Bullfrog will try measuring with the bike running. Took it to the garage this morning and they said the charging circuit was A-OK, possibly a faulty third-party USB charger (switched) was draining the battery in the meantime. And yep, headlight's on all the time on this bike so maybe that's draining the battery while doing all this current super-slow riding. Guess I'll just have to keep an eye on the battery over the next week or so and not stray too far from home until I'm confident it's OK. I'm a learner and this bike's been 100% reliable since buying last year - not a great feeling riding a bike you're worried might junk out at any time - on the bright side, at least I know how to jump start the thing now! Thanks again.