Sunday, October 14, 2007

Update to the battery pack upgrade

Back in May I upgraded the trike's electric assist battery pack to 48 volts from 36V.
This has made a nice difference in the effectiveness of the assist motor, but the one drawback has been how the pack sits in the trike. Juergen and I had quickly installed the pack in the nearest handy container, an old metal toolbox. This meant that the box had to be put in the cargo box of the trike, opened up, and the cable plugged in. It also meant that the pack had to come with me whenever I left the trike unattended for any length of time, since a loose toolbox just kind of says "steal me".

Here's the bare pack:

So I needed a better arrangement, and that was for a sealed box that could stay with the trike. The easiest and most out of the way place to put it would have been along the front end of the cargo box, but since the pack is kind of heavy I wanted it by the right rear wheel, to balance out the weight of the assist motor built into the left rear wheel (the trike when empty can lift a rear wheel on sharp turns, so now both rear wheels have some weight and this no longer happens). So while aesthetically this isn't the best spot it certainly works from a practical point.

My choice of material for the box was corrugated plastic, aka coroplast. If one has to use petroleum for anything then coroplast and duct tape gets my vote! ;) And both worked well for this application:

After cutting and assembling two holes were drilled through the bottom of the box as well as the cargo box floor and bolted in place:

Then, after the pack was fitted inside, I drilled two more holes, one for the power cable, and one for the recharge cable. They came out underneath like this (the small black box is the controller):

Juergen gave me a handy key-operated on/off switch that I wired into the end of the box. This disconnects the pack from the controller while in recharge mode, and to also prevent any minor power drain while parked:

Now that I was no longer taking the battery pack inside to charge it, I had to add an extension to the charger's cable out to the trikeport (the charger can still be removed from where it sits and brought with me if I'm on a longer trip and have to recharge before coming home). So one length of cable comes out into the trikeport and ends in a plug, and that gets plugged into the jack of another cable that I clamped under the seat and ran back under the cargo box to connect with the pack:

Note in the bottom of the photo the bottle for the recently installed Air Zound horn. It's a nice loud beastie that rattles me a bit any time I use it, but it's far more useful in traffic than the squeeze horn it replaced. Here's its business end:

And as is often the case with my projects, Jett supervises:He also thinks the empty trikeport is a good spot to hang out.

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