The Curious Case of Jehu's Sleeping Scooter Batteries - How To Wake Them Up

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The Curious Case of Jehu's Sleeping Scooter Batteries - How To Wake Them Up

It's a tale full of hope, lessons, struggles, and breakthroughs!

Jehu struggled at first, but with his signature spunk and get-it-done attitude, he found the way to awaken these beauties, and to victory!

Jehu has made videos about how to do it. Here's a step-by-step guide to awakening the scooter batteries BMS with a digital key.

First you will need to get the JAG35 scooter battery packs: 40 CELL NCR18650BD 18650 LITHIUM SCOOTER BATTERY PACK W/CASE



These scooter packs normally come with female connectors attached, so you will need to get the male connectors: MALE BATTERY CONNECTOR FOR SCOOTER BATTERIES OKAI ES200G

These are the male battery connectors you need for your OKAI ES200G scooter battery modules to connect to the programmed Arduino that "wake up" the scooter batteries. Each battery pack needs a male connector.

Any voltage below 30v at the Discharge port is an indication that the BMS is hibernation mode. The Internal BMS can be turned on by applying voltage to the charging port (smaller cable) The battery pack will remain in the "ON" state for as long as it has a voltage of 30v or above and without a load.  Applying a load will cause the battery to shut 'OFF" after 5 seconds then remain off for 60 seconds, ON for 5 seconds, OFF for 60 seconds for an indefinite amount of cycles. Using this Arduino Controller connected to the blue cable will instruct the BMS to remain ON for an indefinite amount of time.


This MicroController is used in conjunction with the Okai ES200G scooter Battery Packs. These battery packs require a status/unlock signal to their BLUE (Tx) wire with 9600 Baud serial: 0x3A, 0x13, 0x01, 0x16, 0x79
Then the battery replies with an extensive status report on the GREEN (Rx) wire. We are currently designing a device to display the status report from the battery,  but for now we can turn them on and use them to power many 36v devices.  The Arduino is pre-Programmed with the following code:

void setup() {
void loop() {
// 0x3A, 0x13, 0x01, 0x16, 0x79

You'll need 1 Arduino per scooter battery pack to keep it awake, or aACTIVATING DONGLE to activate x1, x2 or x4 scooter packs. For more than 4 scooter packs, you can DIY a solution to send the signal to multiple packs at once, like Jehu's prototype here: DIY Powerwall Design - PCB PowerStrip.




(Shhh, just between us, Jehu has been working on a DIY Powerwall version of the dongle. It isn't ready for production yet, but it will be soon. Stay updated by signing up for Jehu's early access updates to be among the first to know about new products and deals: )


To power your Arduino you have to use a DC-DC that makes the battery packs 42v down to at least 3.6VJehu recommends the JAG35 ACTIVATING DONGLE which includes a DC-DC, or you can buy it on it's own: DIGI-KEY STH0548S3V3.

Here's a simple diagram for reference.


Most of these battery packs are in hibernation mode, this means that even though the pack is resting at around 30v the output connector shows sometimes 1v to 15v. This means the MOSFETS in the BMS are off.

To use the battery you have to charge the battery pack to 42v. Once charged, some packs will automatically turn on, others will require you to bridge the negative pins on both connectors together using a jumper cable. Applying 42v to the small charging port will also take the battery out of hibernation. If you don’t have the small connector you will have to cut the original connector and solder in your own. XT60 connectors work great here.

Jehu explains more in this video:  Okai ES200G Battery Arduino Controller - DiY Powerwall Building


For more details, check out these videos where Jehu explains more on how to wake up the batteries:

The Best $125/Kwh DIY Powerwall On the Planet

How To make a 72V eBike battery capable of 1800W continuous

This should get you well on your way to "waking up" the scooter battery packs for your DIY power build.

Please share your comments with below, and remember to check out the deals in my store. Keep on building!

- Jehu


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1 comment

  • John OHalloran

    I received my 2 scooter packs this week, along with the 2x dongle. I also received the recommended charger from Amazon. Going to be testing the setup this weekend.

    I plan on using these in my new Shed/Workshop to run my lights and low voltage stuff to start.

    I plan on adding a couple of solar panels on the shed. I’m wondering if you have source for the plugs to go in the charger port, so I can separate the charge & load sides.


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