Battery charges… just not enough

Battery was checked at the start of August, said good. I need to get a more recent test, I had a battery tester but it doesn't have a setting for the low capacity of a motorcycle battery. MOSFET from RoadsterCycle just shipped, so I'll throw that on the bike when it gets here, and if that doesn't fix it, I'll drop the battery from my Ninja (known good) in the Honda to see if that fixes the problem. If it does, new battery, if it doesn't, new stator.

 

What ? - Fit a new R/R to an unknown battery!
Who cares what the ex owner said about the battery back in August.
GET THE BATTERY PROPERLY TESTED before fitting a nice new R/R otherwise you may end up stuffing the new R/R!

 

i recently tried a $30 chinese r/r from amazon on my vtr250 r/r failed after just 65 miles !!!!!!!!!!!!!!

are these things built by prison labor of recycled electronic waste.........or what ?

 

looks just like the crap chinese junk that failed on my bike after just 65 miles !

there's never a brand name or id number on these low-quality duds.

 

Actually, my results have been pretty consistent. During roughly the same time frame I had a Rick's MOSFET in another VFR and put about 18,000 miles in. Unfortunately, I don't have that one anymore.

 

IT WORKS!!!
My package from Roadster Cycle came in last night. Installed the R/R, and took the battery to AutoZone while I had it out, test came back perfect. Hooked the battery up to my shiny new MOSFET, started it up, let it warm up and gave it some juice, and look!

14.3 volts!! Haven't gotten the chance to ride it yet because it was POURING when I came home yesterday, but I'll probably be riding later today and I will let you all know what the results are, but it's looking good!

 

Great news. Enjoy riding.

 

Hmm.
So, after having the RC R/R on the bike for a bit, I’m back. So, when my engine is cold the battery charges fine, and when I’m riding and the radiator fans are OFF, the battery reaches 13.2-14.2V just fine. But my radiator fans KILL the battery (down to as low as 12.1-12.3 while riding or idling), so much so that even after riding for like an hour, if I stall it trying to get it in my garage, the battery gives out trying to start it. There’s no way it’s the R/R because I just replaced it with the Roadster Cycle one, it can’t be the wiring because I used the upgraded harness included with the RC R/R, so my two culprits are the battery and the stator. When I went through “The Drill”, all my stator tests seemed to be fine. But, when I tested my battery, everything came back okay. I have no clue how old this battery is, as the previous owner was the one who installed it. I’m considering switching to a lithium battery in hopes that maybe I could get more battery capacity (more buffer for the radiator fans to run, then shut off and let the charging system recharge the battery, plus lower weight is always cool), but don’t want to drop the money on one if it’s going to have less capacity than a lead acid. (I believe I saw in a FortNine video that Li-Ion motorcycle batteries tend to have less actual capacity than listed on the label— I could be wrong.) Thoughts? Any extra tests I should do? Is it finally time for a blood sacrifice to the VFR gods?

 

When you did the drill you need to do it when the engine is cold and hot. Take it out for a good long ride and test it when you get back. If you did it that way then never mind.
Could be a connection somewhere that isn't too good and when hot isn't passing enough go juice.

 

First thought is the fan running too much ?

Have seen aftermarket fan switches on Amazon and elsewhere which switch at 85degC and are meant for cars. VFR should be fitted with a 100degC switch.

Start bike and leave it idling, note temperature at which fan kicks in.

To find out how good your battery is buy a "ZB2L3 Li-ion Lithium Lead-acid Battery Capacity Meter Discharge Tester Analyser" from fleaBay it will measure the actual Ah capacity of your battery.

 

Radiator fans, as in more than one? I know this might just be a typo but you mention "fans" more than once. There should only be one fan, it's on the left radiator. The right radiator doesn't have one, or at least it shouldn't.

 

Order placed, see you in March
I’ll test what temp the fan kicks on when I next get the chance. Hopefully by the end of the day I’ll get some time.

iirc when I did the drill it was just cold. I might have done it hot at some point, I don’t remember details. I’ll do both when I get the chance, for clarity sake.

You’re absolutely right, I’m just used to saying “fans” for some reason. Force of habit

 

I'd recommend checking the ground spider taped into the main harness in the regulator area..... then the chassis ground on the right side of the frame.

 

Apologies yes only one fan.

 

My apologies, I didn't even see your post. I was replying to connah. I should have used the quote function.

 

Forgive my lack of knowledge but… what exactly is a ground spider? (Pictures help lots, if you can find any)