Using a Battery

Using a Battery

The following information is provided to document an approach I tried to remedy hard starting.  But the more I learned about the OSSA's EFI, the more it became apparent this was the wrong approach.  These bikes will start on a single kick (often after sitting all winter) when everything is working properly.  

One of the first things I did after buying my TR280i was to replace the capacitor with a sealed lead-acid (SLA) battery for testing.  The battery was a bit big to fit in place of the capacitor but seemed to improve starting and showed I was on the right track.  My next move was to zip-tie two 6-volt SLA batteries to the frame (one on each side).  The batteries were wired in series to yield a 12-volt battery. 

I used lead-acid batteries because they are capable of being charged by a conventional charging system.  But they interfered with the fit of the rear fender.

Eventually, I installed a lithium iron phosphate (LiFePO4) battery atop the impact pad on the handlebars.  I connected this through a momentary-contact starter button (from Yamaha TT-R125) on the right-side handlebar so I could apply power to the system prior to starting.  Although LiFePO4 batteries like Shorai are engineered to replace lead-acid batteries on motorcycles, I was a bit concerned about my stab-in-the-dark choice of cells.  I worried about the possibility that overcharging the battery could cause a fire or explosion, so I did not let the OSSA's electrical system charge the battery.  Periodically I would remove the battery from the bike and charge it at a controlled rate.  Eventually, I gained enough confidence with my battery pack, that I installed a diode in parallel with the momentary contact button.  When the button was pressed, the battery would discharge into the OSSA's electrical system.  With the button released, the electrical system charged the battery.  I left the capacitor installed.  I used this method until I bought a TR250i with the Easy-Start.  That bike was easier to start than my 280, and I assumed the Easy-Start had something to do with it so I purchased another Easy-Start.  But I do not think the Easy-Start is any better than the LiFePO4 battery for starting.

My LiFePO4 battery was constructed from four IRF18650 cells (rated 1100 mAh) connected in series.

I have come to believe that the particular map installed has a big effect on starting and whether running the fuel pump via a 12-volt battery is beneficial or not.  

Anecdotal evidence seems to suggest that the Explorer map is receptive to using a battery.