SEVC
  • HOME
  • MR2EV
  • Emax
  • ELISEV
  • Links
  • Contact
  • HOME
  • MR2EV
  • Emax
  • ELISEV
  • Links
  • Contact

Interim Battery Pack (Mixed Thundersky and Nissan Leaf) 

25/11/2016

0 Comments

 
Picture
I have been driving MR02EV for about 4 years using a battery pack consisting of 56 Thundersky lithium-ion cells totalling 201.6 Volts and 12kWwh; it has served me pretty well. Initially my driving was in city traffic 0 – 60 kph so performance was not an issue and the 70 kilometre range was more than adequate.

However, the MES motor and inverter are rated to 400 Volts so an upgrade was always on the agenda and when I started a new job in 2016 the profile of my daily commute changed, so it was time. Whilst the distance was almost identically, the new trip was along urban and flowing roads, generally 60 – 90kph, meaning vehicle performance became an issue and range was impacted.

Since Thundersky's were no longer available it was not a simple case of purchasing more cells, I would have to carefully match them with another brand, or replace the lot.

I chose to replace the Thundersky pack because a friend was able to use the old cells in his home solar battery bank and Nissan Leaf batteries became available. But, due to cash flow considerations I had to purchase the Leaf modules in two batches. So for several months I had 56 Thundersky cells in the car and 14 Leaf modules on the bench, but when a number of the Thundersky cells dramatically lost capacity I started to think …. why not use both, what could possibly go wrong?

Fortunately, both batter types are 60aha and nothing did go wrong when I put 36 Thundersky and 14 Leaf batteries in series. Although the BMS did have a hard time managing the charge cycle, particularly balancing. The mixed pack totalled; 244 Volts and 14.7 kWh.
Picture
The Front Pack - Leaf
Picture
The Rear Pack - Thundersky
I would not recommend building a pack from dissimilar batteries, but it did work, and was interesting to watch on the BMS display when the pack was under load. The Thundersky cells sagged, whilst the Leaf modules remained pretty stiff.
Picture
Interesting graph. Fully charged Leaf Modules, with partly charged Leaf Modules, with the old Thundersky's.
0 Comments



Leave a Reply.

    Michael Day

    I have a Degree in Electrical Engineering from the University of Technology Sydney and am employed in Broadcast Television Industry. My hobby is the (continuing) modification of MR02EV. I am also the National Treasurer of the Australian Electric Vehicle Association.

    Archives

    October 2018
    April 2018
    October 2017
    March 2017
    January 2017
    December 2016
    November 2016
    September 2016
    August 2016
    June 2016
    May 2016
    April 2016
    March 2016
    February 2016
    January 2016

    Categories

    All
    12 Volt Systems
    Batteries
    Battery Managment
    Brakes
    Charger
    General Components
    Inverter
    Motor
    Transmission
    Vehicle

    RSS Feed

Proudly powered by Weebly