some basic battery questions, please help.

Hi all,

I have some basic battery questions and I would if you guys will be kind enough to help me with.

I have a 1999 R1 and got it back in 2009 and never changed the battery myself and it is a weekend, dry weather, show off bike LOL. So, I don’t really use it very much and last time I uesd was in mid Oct and last week I tried to take it out to ride and as you would expect it struggled to start and eventually the battery ran out and it won’t start.

Now, I am facing a bit of a decision make situation, I can get a car battery and inverter and keep it charging in the garage (because there’s no power source in the garage) or just put a new batter in instead (because I don’t know how long the battery been in the bike and maybe the condition is so poor that it simply won’t hold charge).

What would you do? I can’t afford to do both ( change the battery and get car battery and inverter).how long a battery usually least before I really should change it?


First thing I would do is check the electrolyte level and condition - depending on the outcome I would then consider toping up the electrolyte and charging it.

If you don’t have an electrolyte tester, electrolyte or battery charger then it might just be easier to buy a brand new fully charged battery.

If this is just a show off weekend bike then you might want to remove the battery and keep it in the house on an optimiser instead of going to the hassle of getting a car battery, an inverter and you’ll have the hassle of having to charge the car battery every so often. :slight_smile:

or maybe something else so somewhere on the battery will be a date and a few simple tests will reveal the condition of the battery.

A car battery, voltage inverter and battery charger won’t solve your problem. A 12v solar battery charger might once you’ve diagnosed why the battery is flat and rectified any faults. An automotive multimeter might be a good investment :wink:

Test the battery standby voltage, if necessary charge and retest.
Test the battery voltage under load (cranking amperes).
Test the charging system.
Test the standby current drain.

I’d suspect the battery because its over 5 years old and only used/charged occasionally but don’t just replace it without working through a proper diagnostic test sequence, you could be swapping out a perfectly serviceable battery.

thanks for the replays. i was thinking to take the battery out and change it over night but i was a bit worry about it will mess up my alarm if it detect there no power for a long period of time. would be a real problem or i am just scare for no good reason?

Best to check your alarm manual. My car alarm has a backup battery which gives off chirps for 4-5 hours when it loses 12v power.

if your alarm is declared on your insurance, it’ll probably invalidate your policy if you remove the battery every night.

It would be tricky for the insurance company to notice and then demonstrate that the battery had been removed, though.

Did you ever get the bike started? If so, we can make some fairly educated guesses as to what’s wrong on the basis of what the battery went on to do.

It happens from time to time because I only use it very occasionally (give you an idea how little I use it between my last and this year MOT, I only clocked 400 miles) and everytime when I couldn’t start cos the battery was flat I could always jump start it if I have someone to help me so I like to think the alternator is working fine.

Therefore, I really think it is a simply old poor condition battery that doesn’t hold charge very well but I can be wrong of course. Since , we are on the old battery subject, what is the best bike battery? I was told YUASA is the one to go for. Any views on that?

Alarms will drain the battery if the bike isn’t used. Those sensors need electricity. On my GSX it takes about three weeks, although mine isn’t a factory fitted alarm, perhaps those are more efficient. I keep the bike plugged in to an optimate when not in use. I also have a DRZ, which doesn’t have an alarm, and that can go for much longer without being plugged in.

Have you thought about a solar trickle charger? Something like this:


Yeah, if you’ve got an alarm fitted and when the bike runs the battery behaves itself then it’s probably just the alarm flattening the battery. For the sake of the battery’s health it’s worth working round that, if you can’t get near a mains supply it’d be worth getting hold of a larger battery (like a car or bike one) and leaving that plugged into the bike, taking it off to recharge it overnight every so often.

Ok, I have decided I will get a car battery and DC converter to keep my R1 battery stay charging over the winter but my question is which Watts I need for the converter. There’s a lot from 150w to 2000w.

I have done a bit research but I still don’t understand which Watts converter I need.

Any clever people here can help?


Ohms Law is your friend

Watts/Volts=amps a dead 80 amp hour battery overnight :frowning:

This should do what you need:

Can buy from eBay here: