Sparrow / NmG
Greg Williams, converted his Sparrow.
* 52 CALB 60 AH * 24 under the seat * 28 under the hood * 169 V nominal * 10 kWh nominal * Zivan charger
I have 52 CALB 60 AH cells from Manzanita in Kingston, WA. I sent my Zivan to Elcon for modification for the Lithiums. I cut no fiberglass for the batteries and all my cells are upright and on one single level. I didn't want to stack cells like the Optimas. The Zivan fits in the same location as before but I need to rebuild the mounting bracket.
Before I installed the cells, I lined them all up on my workbench to equalize the voltages. They came with a data sheet on the whole set with individual battery voltages listed. Pretty cool. I numbered all the cells so I can keep track of them. To strap them all together electrically, I used a couple rolls of plumbing solder with a wrap around each battery bolt screwed in part way. To my way of thinking, this acted as a sort of a fuse for each cell. I hooked up my Variac power supply and put a three hour charge current into the batteries whenever I walked into my shop. This went on for a month while life went on doing other things. My Variac limits at 20 amp so there was only a small current going into each cell in parallel. When I finally disconnected them for installation, the voltages were almost all identical. It surprised me that there was a couple hundredths of a volt difference in a few. Close enough, though.
I did not de-fang my Sparrow yet but I did change out lights to LEDs, put a switch on the headlight for daytime, install Myer's lighted mirrors and change out the burnt heater hoses for aviation SCAT tubing. There was a fair amount of cleaning and adjustments in my 14 year old sparrow. It has about 11K miles and the original owner said he was on his second set of Optimas when I got it last year.
Next step is to improve my battery straps, build the charger mounting bracket and start driving it around. I have room up front for any sort of BMS but I have not decided what to buy yet. They all seem real expensive. Of course, the cells were very expensive too.
Now that I know the rest of the Sparrow runs well, I am ready to pull all the battery straps off and do the following: install better lock washers, put No-Ox on each connector, install a fuse in both compartments, install some sort of strap/containment structure around my cells, put a plexiglass cover over the front batteries, install connectors and wires for whatever BMS I end up using.
The Sparrow 202 arriving to the shop
Cells under the seat
Cells under the hood