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Adding an active balancer as well … it works in conjunction with the ant BMS to balance the pack quicker. Balances at a rate of 1100 mA. www.vextrek.com

UPDATE: Recent changes to the 72V Vextrek pack include the active balancer referenced above as well as the use of .17 mm thick copper for the parallel/series connections. The thicker copper (.25mm thick) previously used was “overkill” given the maximum current of this pack would only be 450A. We...

Adding an active balancer as well … it works in conjunction with the ant BMS to balance the pack quicker. Balances at a rate of 1100 mA. www.vextrek.com

excellent. Can definitely use that. I can see how it would make the connections much easier. Thank you.

Interesting idea. Will look into it. Thanks!

We have made a few packs of various sizes. Basically, all are rectangular in shape but we can make it any voltage or aHr capacity needed.

The Vextrek prototype lithium ion pack for dirt bikes is almost ready! Our goal was to “GO BIG” on everything. This is a 72V 50aHr (20S/12P) pack of Molicel P42 cells connected with .25mm thick copper. Since cooper is 4x more conductive than nickel, this pack can easily handle high current. As...

Pack is connected with .25 mm thick pure copper sheets for the series and parallel connections and thicker copper for the terminal connections. Recently added BMS wires and looking for any other suggestions that can make this pack better. Thanks. https://fb.watch/gSSUy5nUy3/?mibextid=qC1gEa

Prototype Lithium Pack Update: Next step for the custom built 80V/52aHr lithium ion pack for Shandoka Electric Motorcycles will be “bench testing” followed by actual road testing. Initial diagnostic tests show that this is a well balanced lithium pack Vextrek. The difference between the highest...

No problem. Ordered the cell holders direct from AliExpress. Took about a month to arrive but pleased with the product. Here is the link … https://a.aliexpress.com/_mOjNMYa

Generally speaking, the more cells in parallel the less impact a dead cell will have on that particular grouping. Tesla packs rarely are impacted by a dead sale because they have so many in parallel… 74 in parallel on the earlier cars if my memory serves me correctly. When you have smaller...

That’s a pretty cool design. If I’m seeing at correct it basically is a “Copper bridge” to the center of the cell. Only downside would be copper that wide would not act as an “individual cell-level fuse” because it can conduct so much current. As long as it’s .4 mm or less in thickness, the...

Thanks. Description applies to the go kart battery we are currently using as well as an electric motorcycle battery we are finishing now. Have not made one for an ALTA but would love to do it soon.

We use a Sunstone Pulse Arc welder (P250i) to connect the Molicel P26A cells with .25mm thick cooper sheets. The pack performs very well with no heat issues. Using a di-lithium BMS with 10 thermistors and we routinely pull 600A of current. Disclaimer: Pack does not utilize cell-level fusing so...

Close up shot of the spot welds using .25mm thick pure copper on the Molicel P26A cells. We have a pulse arc welder which allows us to weld copper consistency.

Back-to-Back 1/4 mile passes at the Carolina Dragway. Tentative plan is to be at the Lamar County Speedway on June 11 and the Atlanta Motorsports Park in late June or early July. Target Performance Level: TAG Senior Series

Update:110 mph in the 1/4 mile and 87 mph in the 1/8 mile. Still working on ways to improve the 60ft times but we are pleased with the results. The Vextrek lithium battery performed well and all other drivetrain “vital signs” were good. Made about nine passes at the Carolina Dragstrip in the...

About to track test this new battery. Have 10 thermistors (5 on each module) so will be monitoring heat closely. Will report back. 👍

No heat issues with the previous pack (20S/21P) but that was using Samsung 25 cells and pulling 500A max. Plan to test this new pack extensively on a go kart in early March and will report the results. Each of the modules have 5 separate thermistors placed around the pack and the SOC gauge we...

This is our new 100 Volt lithium ion battery pack for the next electric go kart project. The two modules shown below will be connected in series to obtain a nominal voltage of 100V and the pack has 46 aHrs of energy storage capacity. The soft drink was included for relative size comparisons. We...