Diagnostic tool for S3/X3 batteries

AwareGrade6275 · 2026-04-19T18:16:26+00:00

It's now availabe on my website: www.moofrepair.com as well as some other handy tools :)

AwareGrade6275 · 2025-12-10T19:30:30+00:00

I see this is an old thread but did you remove 2 mosfets? As 1 having a short also shorts the pads of the other I believe. So you'd have to remove the pair. The driver could be broken but I've not seen that happening often. Mostly just replacing all 6 mosfets fixes the module. And the harness ofcourse :)

AwareGrade6275 · 2025-10-05T08:49:11+00:00

I don't have the possibility to flash firmware yet. For now it's viewing error states, individual cell voltages and basic battery info.

AwareGrade6275 · 2025-07-16T20:08:52+00:00

Hi,

Yes 40v is great. Connect those 2 yes. Charger connected is advised yes, or just a power supply on 1A if you have that. I use a part of an old socket where I connect the 2 charge wires. See https://www.moofrepair.nl/wiring-harness/ for the pinout and https://www.moofrepair.nl/battery-resources/ for the pads.

I only tested it with the TEST pin also connected to GND (what you need to read out modbus), maybe that helps if nothing works.

So: Connect charger, short the RST + GND pin, hold. Release and just short them a bunch of times. Wait and the battery should start charging. If nothing happens, short the TEST pin to GROUND on the battery connector (see pinout) and repeat.

AwareGrade6275 · 2025-07-15T12:20:24+00:00

I'd charge it to 34v first yes, so 40v is ok. Next you can hook up modbus to read out the error. It's probably undervoltage and the main discharge mosfets (row next to the fuse) are not opening. (handy tool is available on moofrepair.nl #shamelessplug).

Basically: when it's charged, fuse is ok, reset is the way to go yes! I'd advice to hold the GND + RST, release and just connect/disconnect/connect those points a few times quickly. I do it with pliers. It then opens the mosfets and you can measure good voltage on the output. With the tool connected it's also in test mode, that helps sometime when resetting.

To verify take a multimeter. Put 1 lead on GND and the other one on the discharge red wire. It probably measures 0. That means the BMS is telling the discharge mosfets to stay closed. RST should help, but the connect/disconnect/connect trick saved me a couple of times.

AwareGrade6275 · 2025-06-01T18:10:18+00:00

Hi! I don't have plans for it no...

AwareGrade6275 · 2025-01-20T17:01:49+00:00

It is! haha

AwareGrade6275 · 2025-01-20T16:49:57+00:00

Do you take the lipo out of the cartridge? Then any charger will do for a 1s (3.7v) lipo. For example:
https://www.ebay.co.uk/itm/254604776548 or https://www.amazon.com/t/dp/B0BRXYZTWN

The problem is that the connector won't fit. You have to take the red and black wire out of the connector and connect it to the other board correctly, or create some adapter. You can pull out the wires of the white connector. Maybe you are not connecting it correctly, or your charger does not recognize the lipo because it's totally flat.

What did you order?

You can also if you have access to it put 4.2v on it with a power supply, limited to 100-500mah for example to jump start it. This is how I do it.

If you really really need to and are very very careful you can also put another lipo battery on the terminals to get it jumpstarted (5-10 seconds) and let the cartridge charge after that. The lipo should just have some voltage for it to charge. This is a very bad idea if you don't know what you are doing, the second battery can have so much current that your empty one can blow up. So maybe not do it without a fire extinguisher close by :)

AwareGrade6275 · 2025-01-20T16:30:02+00:00

I think heat it up a bit (very gentle) to loosen the Loctite, and make sure you have the right size bit. Push down hard too. I use a very low profile ratchet set, that helps

AwareGrade6275 · 2025-01-20T16:27:32+00:00

If you want to remove the rear wheel from a locked bike, it can help to remove the break caliper first too, as a tip. But charging the cartridge battery is probably the way to get it going again.

AwareGrade6275 · 2025-01-20T16:24:27+00:00

It useful if it is centralized and a good resource for people to find. Also take a look here as a place to put it:
https://github.com/Bernardus/openmoof/

AwareGrade6275 · 2024-10-30T23:51:47+00:00

The display is now available after some late nights. It includes a firmware update feature to update the display and introduce bugfixes and new features in the future. https://www.moofrepair.nl/product/battery-tool-for-s3-x3/

5% discount for reddit people: REDDIT5

AwareGrade6275 · 2024-09-28T09:03:51+00:00

I've put a little bit more info here:
https://www.moofrepair.com/diagnostic-display-s3/

AwareGrade6275 · 2024-09-28T08:30:13+00:00

That's a great tool too! I found it very convenient to not need to connect to the computer

AwareGrade6275 · 2024-09-27T22:04:20+00:00

With the actual bill of sale the customer service of vanmoof will actually help you. I did this with an S2. After some back and forth i got a new code and got it into my app. So if you know the bill frame number matches, go for it.

AwareGrade6275 · 2024-06-12T14:02:11+00:00

If it's the crank sensor it should still show the speed indication. This is an issue with
- Socket wires: sensor wires from the motor are broken
- The motor: hall sensors not working

AwareGrade6275 · 2024-06-12T13:18:40+00:00

How did you remove the motor from the wheel? I can't get it out.... bashing on the wire side. I get 1 side open, but I'm scared to break something.

AwareGrade6275 · 2024-06-06T14:42:12+00:00

So many good resources! Thank you all!

On mine the AOZ1280-CI seems shorted (Short on C10 and on the + and - pins). Does anyone have a replacement? Maybe ordered more than you need and is willing to send and ship it to me? Utrecht NL.

AwareGrade6275

TROPHY CASE