Checking Your Battery Level

(The Flashlight Method)

Pokie November 2001

Ok, so BMW made it a bit of a pain to get to the battery.  Yes, the fuel tank, seat and side covers will have to come off (please see my “Tank Off” artical).  That said, the electrolyte level in your battery would still need to be checked at least once a year (more if you have been experiencing electrical difficulties).  The following was noted as I was doing the job using the tools I prefer.

I like to use ” drive tools for this job, 10mm socket and a 3” extension on a ” ratchet are perfect.  Use this set-up to disconnect the ground or negative wire from the battery (I usually store the nut and bolt in the terminal on the end of the wire so-as not to get lost). While you are on this side of the bike, go ahead and slide the breather elbow out of the battery and let it just dangle there (Don’t pull the breather tube out of the loops on the frame as it can be a little fussy to get back in).

Now remove the nut and bolt from the positive terminal (again, store the nut and bolt in the end of the wire).  Unhook the rubber battery strap and tuck it out of the way.  The battery is now ready to be lifted out.

To check the electrolyte level, set the battery down on a flat, reasonably level surface.  This is going to sound a little bit funny but bear with me…  Like in the photo, take a flashlight and shine it through the back of the battery.  While shining the flashlight through, rock the battery back and forth (front to back) to see the level (you may have to try different positions for the flashlight until you are comfortable with the view).  Keep your battery topped up to the “Upper Level” mark on the battery and no more.  If you do overfill your battery, the “over” amount will slowly find it’s way into the overflow tube and drip onto the floor under your bike.

Shine the light through your battery to see the level.  I find rocking the battery back and forth helpful to see the level.

When refitting your battery, always attach the positive lead first (the red one).  This will reduce any chance of having a shocking experience.

Topping Up

Things to keep in mind;

Battery acid is NASTY stuff.  Wear eye and skin protection and don’t drip any on your clothes!  If, by chance you get some battery acid on your skin, wash it off IMMEDIATELY.  If battery acid gets splashed into your eyes, rinse your eyes with LARGE amounts of water (a hospital emergency room visit may be in order).  If you get battery acid on your clothes, holes will appear in the fabric after washing.  A little safety practice now is worth more than a whole lot of being sorry later.

If your battery needs to be topped up, use only distilled water.  DO NOT OVERFILL your battery!  Overfilling your battery causes two problems, firstly the leaking of battery fluid out the overflow tube.  Secondly, overfilling your battery causes the electrolyte to thin out, weakening your battery.  If you think you can rectify thinned electrolyte by adding more battery acid, think again, it doesn’t work.  Forgetting about your battery or putting off it's service can be very costly.  Take for example, if the electrolite level drops below the plates, no amount of adding acid (straight or diluted) will save your battery.

With that out of the way, I use a small hydrometer not only to test the charge level of my battery, but to top it up as well.  A small ATV or motorcycle hydrometer is available at most any auto supply store. If you need to add a lot of distilled water, you can obtain a small funnel at the grocery store.  To add water to your battery, you need to remove the caps.  If your battery is stock, the caps are compression fit.  Just pop them out with a pair of pliers or a small screwdriver (keep in mind that when the caps “pop” out, they may flick a drip of acid at you).

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Copyright 2009 Pokie Parmidge