Thursday, November 10, 2016

We're Lovin' LEAF

Lovin' Life with LEAF salvage, that is.  The two collision-salvage battery packs arrived this week, as did the prototype Wolftronix LEAF Pack Sniffer.  This amazing little device turns on the BMS and reports back the pack voltage, average cell V, # of bars of remaining capacity, identifies the high and low voltage cells, and then scrolls through all the individual cell voltages.  One of the packs was sitting at 396V with four bars of capacity, the other at 383V and 10 bars of capacity.  Voltage as a state of charge indicator is mainly valid at the upper and lower end, and these packs were built two years apart.  I think they will balance out nicely, as individual cells voltages were tight after months of sleep, with only 6 thousandths of a volt difference between the highest and lowest cell.  Most were within 3 thou..  Here's a video of the sniffer in action!
Leaf Pack Sniffin'

The packs arrived on a rollback wrecker, so without a forklift we very carefully set the back edge of the pallets on the ground and then drove out from under them!


It may seem scary to sic a student with an air chisel on a highly charged battery pack, but research revealed the safety of this technique, as the sealed surface to be separated is outside of a one-inch protective lip of steel (and by another air gap and metal module covers on the inside) meaning one would have to overshoot the target by quite a distance and cut through multiple layers of steel after the target of a single layer of sealant! The air chisel made short, but very noisy work of this job, much to the students' delight!  The students quickly learned to distinguish by both sound and feel whether the chisel was hitting sealant or steel!

1 comment:

David Meyer said...

Hi Jay,

Following your build here and on SEVA mail as your Ranger project is likely to be the model for me to follow when I convert my Nissan 720 pickup to 'lectric. I'm a complete novice at this so when I do decide to get started I hope I can lean on you and these classes for some help.

First of all, I had already decided before I saw the start of your build that I wanted to use two salvaged LEAF packs to get greater range than I currently have in my leaf. Also, I figure my truck is a) lightweight enough to be able to take the added weight of two packs and b) sturdy enough to handle the additional weight.

Like you mentioned, I too would like to be able to build the truck in a way that I can still continue to use the bed of the truck for hauling stuff. My idea has been to lay the batteries in a pancake style under the bed, if possible. I also don't mine sacrificing some of the space in the bed, near the cab, if necessary.

On to my questions: Where did you get the LEAF battery packs and what did they cost? Are you using the original Ranger EV motor and controls? If I want to use mostly all systems from the LEAF (motor, electronics, wiring, battery pack) can using the larger battery pack (2 into 1) make for a more powerful output? I would prefer to design a system that prioritizes power over range, but I'd still like to have a 100-mile range possible when driven conservatively.

Feel free to write me back at if you'd rather have this conversation be less public. Thank you!

- Dave Meyer