Last July the trike received an electric assist motor courtesy of my friend (and trike co-builder) Juergen. The power came from three 12 volt, 7 amp-hour batteries, a standard kit used for e-assist bicycles. It certainly helped with the hills and bridges, along with helping me clear intersections more quickly (and safely), as getting going from a dead stop with a full load was always an effort. But the power band was very narrow, since of course the kit was designed to help a 30 or so pound bicycle, not a 100 lb. cargo trike. So the motor helped, but not a lot...
A few months ago Juergen suggested adding a 6-volt to the set-up, or even a fourth 12-volt. The controller is only rated for 36-volt, so if I went right to 48V I was cautioned against using full throttle on a regular basis. Juergen also said get a 12 amp-hour battery, because if I decide to stay at 48V then batteries of larger capacity would be even more helpful, and he could get another 3-pack of that size. So that's what I did, and for a little while I had a larger 12V (bought at Alexander Battery here in Ottawa) added to the existing 36V pack. The only hassle was that I only had the 36V charger, so each time I used the assist had to join the batteries together, then when it came time for recharging them I had to separate the 12V and put it on its own charger (same 6V-12V charger I use for the trike's 12V lighting system). This got a little tedious, and I was concerned that the constant plugging and unplugging might wear out the connectors (I've been using the trike a lot since I got hit by that taxi, as my cargo trailer was destroyed in the collision and I have not yet built its replacement, so anything that needs to be moved requires the trike).
So the decision was made to go to a more permanent 48V set-up, and last Saturday I acquired a Soneil 48V charger from Darryl at Econogics. Then on Monday Juergen and I got together and he supplied a new 36V 12 amp-hour pack and wired my 12V into it, fitting it all into an old metal toolbox for now.
The results are great, with a noticeable boost being given. With the cargo box empty the trike boots along nicely (if I'm feeing lazy). But mainly I'm using it to get up to speed more quickly, and not slow down so much when climbing. There's at least enough power now that when I'm at cruising speed I can boost that a bit more (the old set-up did not add to my top speed), but I don't usually do so unless in a hurry. The next step is to figure out how to mount a battery box under the cargo box so I can leave it there, and not take the pack inside each time I park the thing. The assist has become an integral part of the trike's functionality, making it much more pleasant when hauling any kind of weight around, not to mention showing up for those dress-up gigs with a little less sweat...