Lightweight Battery (2 of 2)

(part two of a two part article)

Fitting the Speedcell Battery

Remove the seat: Unlock the the rear seat pad, remove the two bolts that hold on the seat, then remove the seat. This gives you access to the rear bolts that fix the gas tank. Remove the seat by sliding it back and up. Check the owners manual for more information and diagrams on removing the seat.

Be careful not to damage the rubber grommet which holds up the tail light assembly. Put a dab of Vaseline (petroleum jelly) or suitable grease on the inside of this grommet. This will help you replace the seat without damaging the grommet. When replacing the seat I also like to put a drop of Loctite on the bolts holding it down. These bolts have a tendency to come undone due to vibration.

Click to enlarge

Undo the gas tank: Remove the four bolts that hold down the gas tank (two front and two rear). Now lift up the front of the tank to give you access to the battery. Be careful not to pull the fuel lines and fuel pump wiring harness too tight. Support the tank in this position with a suitable piece of wood. If you have something the right size it can be slotted under the tank in such a way as to support it in a stable way.

The alternative is to disconnect the fuel line (undo the bayonet connection), remove the fuel breather hose, disconnect the wiring harness to the fuel pump and then completely remove the tank. I did not do this because I had trouble getting the fuel line disconnected and I did not want to damage the bayonet connector. This is probably just me not knowing how to do it properly.

I have a philosophy related to motorcycle maintenance. If it requires more force that you'd expect to undo a part then you are doing it the wrong way. Stop and think again. This rule only applies to modern motorcycles :-).

Remove the old battery: Black = negative, red = positive. Always undo the negative battery terminal first! This is because the negative terminal is connected to the metal parts of your motorcycle, making them all negative (also known as "earth"). If you undo the positive terminal before removing the earth, then you could short-circuit the battery by touching any metal part of the motorcycle with your metal spanner. You do not want to do this! Once the negative terminal is undone, it is safe to put a spanner (or screwdriver) on the positive terminal.

Looking down. Note all the extra space. Click to enlarge.

Fit the Speedcell battery: Do not remove the plastic cover on the new battery's negative cable just yet. This is to prevent the two leads coming together and shorting the battery (bad).

The new battery fits snugly into the existing battery box. I fitted a strip of rubber adhesive padding between the metal bracket at the front of the battery box and the new battery (see right-most red circle in image above). This makes the fit tighter and prevents the battery from rubbing directly against metal.

I used two fairly heavy duty cable ties to secure the new battery. One at each end of the battery (see photo). These simply go under the metal battery box and over the new battery. I wrapped a smaller cable tie around these two to stop them from being able to slip apart (this is not shown in the photo). You might want to wrap a third cable tie around the middle of the battery for extra security.

Remove the black cable that used to connect to the negative terminal of the old battery. The new battery's negative lead will bolt directly to where the other end of this cable connects to the frame (top red circle in the image above). But don't connect the negative battery lead yet as this will earth the whole bike. Use the rubber protective caps from either end of this old cable to fit over the two red and black (positive and negative) leads of the new battery.

Now bolt the battery's positive (red) lead to the two cables that used to connect to the old battery's positive terminal. I used the old battery's terminal bolt for this. Now cover the exposed metal where these wires are bolted together with the black rubber protective cups. I used a small cable tie to secure the positive lead to one of the cable ties that hold down the battery. Position the lead so that the join is not able to contact with any metal part of your VUN. See bottom red circle in the image above.

Now it is safe to remove the protective plastic cover on the Speedcell's negative (black) lead. Bold this lead into the position where the old negative cable used to connect to the frame and place the protective black cap over it (see top red circle above).

Test that the battery is securely positioned and that the positive terminal is not exposed to any metal parts of your motorcycle.

Now you can replace the tank and seat.

Testing the new battery

My Speedcell battery arrived in the mail fully charged. If your's is not charged then you will need to do this first. With the new battery fitted my VUN started right away. I have been using the VUN fitted with the new battery for a few weeks now and I can say that it works fantastically well. I have had absolutely no problems and the bike always starts strongly.

It is probably an illusion due to the fact that I just got back from a long trip with a heavy tank bag attached, but the VUN does feel lighter. Whether or not I can really 'feel' the difference, the VUN is 3KG lighter than before. I am very happy with this change and I can't wait to take the next steps towards a lighter VUN.