Advice needed on battery etc

Afternoon all.

Quick question, last few days my bike has been a little slow to start, it does start but does the chug chug chug start whereas it usually starts smoothly.

2013 Hornet, good service history, replaced battery and regulator / rectifier 2 years ago. I commute daily 10 miles each way. I did have 7 weeks backpacking in December so bike was sitting there, but amazingly it started first time on my return.

Just wondering what I need to do / look out for? I am pretty clueless about this sort of stuff. Am I looking at my battery failing, should I check spark plugs etc? I would rather pre-empt than get stuck at work having to get a call out.


No doubt someone will be over soon to explain to use a multimeter and that it’s a must… If you know how to use one and understand what it tells you, and are willing to spend the time to find out what the right measurements are, go for it.

I take a different approach. Battery dies, I replace battery… if it burns through two different batteries, take it to someone who knows.

Mine did the same thing, started fine after period of being unmoved, then wouldn’t.

In my case I had a Motobatt battery with too few cold cranking amps… Bought an original one, problem solved.

I also bough a cheap charger to keep battery charged when I knew wouldn’t use it for long period, or wanted to charge it after a long time off. That was a pain in the ass as on the adventure batteries are a ballache to remove and I couldn’t keep it charged with the battery in place

Your journey time isn’t long enough to recharge the battery. Suggest you hook it up to trickle charger each weekend.


NT will be along soon. Hes your man when it comes to batteries!

That’s a very good point…

I would have thought 35 minutes each way at between 20-40 mph would be sufficient? I really don’t want to be pulling out the battery every weekend if I can help it.

10 miles was fine to charge the battery on my hornet ('09).
I would go on a good ride out anyway, if it doesnt settle then on the battery optimiser for a weekend.
next step would be to replace the battery before looking at anything drastic like spark plugs

It’s not unknown for a two year old battery to need replacing. Charge it fully with a proper battery charger and keep an eye on it.

I’ve had various experiences. The first battery in my 748 lasted well over ten years and it was abused: the bike would be parked unused for long periods and sometimes it would chug just enough to fire, sometimes it would be completely dead. I would take it out and recharge it. It put up heroically with this abuse. I eventually replaced the poor thing and treated the new one to an Optimate. Two years later it was dead and needed replacing.

You don’t have to pull the battery out when using a trickle charger.

I don’t think 10 miles is enough for many batteries and certainly not older ones. It’s only my advice to help you out.

I think it’s the answer to your problem and costing £25.

Cheers, I do appreciate the advice. Unfortunately having my bike parked on a road means taking the battery out to trickle charge in my flat. (I do have a charger, it is just the effort annoys me.)

I think a cruise down to Yeovil this weekend should let me know if it is the distance issue.


Cheers RS. The ride out would be my preference every time :grin:

Well you could just replace the battery except it may be that the battery is fine, it may be that some other fault is causing the battery to prematurely fail. You need to prove what is causing the battery’s loss of charge?

Check the battery’s initial level of charge with the ignition and all electrical circuits switched off the battery voltage should be greater than 12.4v, if below 12.4v then fully charge the battery. Calculate the number of hours to fully charge a flat battery by dividing the battery’s Amp hour (Ah) rating by the battery charger’s charging Amp rating and adding 10%. The slower you charge it the better. With a fully charged battery and multimeter in hand you can then test the battery.

Check voltage drop with the engine off, ignition on and all lights on expect between 12.5v to 12.8v slowly dropping to no less than 11.8v, if there is a fast drop to 11v suspect the battery.

Check electrical loading with the engine at 1,500 RPM and all electrics switched on expect the initial level of charge + 0.5v or greater.

Check cold cranking while cranking the engine on the starter motor expect battery voltage to remain above 9.5v.

Check standby current drain this varies from vehicle to vehicle so check the vehicle manufacturers specification for your model, typically drain will be something less than 0.5mA but with some vehicles can be as high as 2mA.

If the battery proves serviceable check the charging system. With the headlamp on high beam and the engine running at 5,000 RPM battery voltage between 13.2v – 14.2v is OK, if it is less than 13v suspect a stator fault, if it is more than 15.5v suspect a regulator/rectifier fault.

You got that all clear RS?

That is very comprehensive and useful! Thanks all. I think I have a new weekend project, multimeter ordered.

Really appreciate the level of help everyone.

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