Hi guys,

the CBR125R in question had a battery fitted when we purchased it, but it went dead after a few days. I checked the terminals with a voltmeter after bumping it and it showed just over 14 volts, so I went and purchased a new battery for it from Halfords (Sorry!)

The battery I purchased was the same one that was in the bike. It is a HB4L-B (45amp, 4ah, 12v)

However, when I removed the old battery it shows an activation date on the side of 07/2017 (about 6 months old) but decided any battery can die, and replaced it anyway. Obviously, as I am typing here, this did not solve the issue and the battery still dies.

It is only being ridden every other day, but surely this would be enough to keep it topped up? So today, I once again checked the voltage when running and it came in at just over 14 volts. I then removed the stator case (and nearly poohed myself when oil flooded out) and checked all the coils and continuity in there. It all checked out fine with no earth to the 3 yellow leads and 6 ohm resistance between each one, suggesting to me that it is all fine. all of the connectors looked in perfect health with no corrosion.

I am a little lost as to what to try next. Are there any common faults or is it a case of trying each item individually now? How would I know if they are draining the battery? There are no heated grips or any mods on the bike at the moment (except after market led indicators on the front)

Any help would be appreciated,

Howard

 

Have a look at this Howard, and test the Reg/Rec

 

ahh, a good old flow diagram for fault finding. I will give it a go. See sometimes all you have to do is ask. Thanks a lot, I'll let you know how i get on!

 

Since the battery is new (X2) and the charging voltages are good, it would suggest that there is something drawing power when it sits assuming the battery is really dead.

How do you know it's dead? Perhaps it's a starting system problem. Bump starting bypasses the starter also...

 

as soon as the battery is charged and put back on the bike it fires up, so I have to assume its a power issue and not a starter one

 

Maybe parasitic drain Howard have a look here

 

Checked the parasitic drain (thanks guys) and found no current leaking from the bike at all. This morning I went out and listened to him trying to start it and it would seem that in the cold, and it is cold, the battery does not have enough vavavoom (tm Renault) to crank the bike long enough to start. It starts fine once warm, so is that a case of more ampere hours or amps needed to turn it for a longer period?

Does anyone know what the largest battery battery is that can fit in the bike. The battery in there is sold as a scooter battery, and perhaps I should be getting something bigger as long as the physical dimensions fit ok.

 

Hi Howard , which 125 do you have , is it carbed or injected model

 

carbed

 

choke operating at the carbs ? Worth a peek