Friday, April 26, 2013

Install 2 AA batteries as shown

After finishing up this week at school I started installing the shiny new batteries in my car. The BMS boards went on without too much issue and the bus bars fit nicely with one exception: when the batteries are positioned end to end, the bus bars are a little bit too long. Luckily they are fairly easy to bend and I was able to avoid having to make new ones. Here's the first pack of batteries (35 of the 85 cells) in the back of the car with the BMS boards installed.



I briefly hooked up the 35 batteries in this box to my laptop and all of the BMS boards worked and reported that the batteries are within +/- 1mV of each other. This is great news as the pack won't need to spend very long balancing after the initial charge. I was just able to get started fitting BMS boards to the second pack before sunset, which I should be able to finish tomorrow.


Next step is to fit the second box under the car, connect all the cat5e cables for the BMS, connect the (comically) large power pole connectors between battery packs, and finish the 12V wiring to the BMS controller. Ideally I'll be finished by the end of the weekend, given the wrath of Murphy doesn't come into play to a huge degreee.
That's it until tomorrow, when hopefully I should be able to charge the batteries for the first time.

Tuesday, April 23, 2013

They're here!

The lithium batteries are here at last! Or more precisely the Lithium Yttrium Iron Phosphate batteries are here at last. After 500 miles and ten hours of driving (thanks Sean!) I am now in possession of 85 of the cells shown below, each one has a nominal voltage of 3.2 volts and a capacity of 60 amp hours. All three crates weigh a total of 527 pounds and the batteries themselves make up about 460 of that, with the rest being packaging, copper bus bars, nuts and bolts that are included.

 

Over the next week or so I'll be inventorying and checking all of the batteries, installing them in their boxes for the car, connecting the BMS to each cell, and wiring everything to the charger and controller in the car. I estimate there is about 10-12 hours worth of work to get the car moving and charging, assuming there's no serious snags. You can be sure I'll be spending every waking moment I can spare working on this though!

one of the three boxes opened




That's all for now. Oh and on a side note, I got a new vanity callsign! It's N6LAN, or Nolan with a 6. Nolan with a zero was taken. and Nolan with a 1 just sounded weird to me. Until next time, which should be soon, N6LAN clear.