[Cheatzy] active device to cheat the original BMS with higher capacity batteries

As already announced here , I have completed the test with the cheating device and therefore I want to propose it to your attention.
Cheatzy is an active device, based on a 16-bit ADC (analog to digital converter) and a DAC (digital to analog converter), both controlled by a CPU, which cheats the original BMS of the Twizy, by manipulating the current value provided by the battery current sensor.
You know that when you convert the battery to new cells, usually with a higher capacity, and your hold battery had a reduced SOH, you will face the so-called "reserve canister effect", i.e. you will reach 0% SOC before the battery is really empty, and turning the Twizy off and on, you will gain some extra SOC. This happens a few times, until the battery is really discharged.
This effect isn't so nice, because at these low SOC percentage, the Twizy has a reduced power and driving it in this condition isn't so fun.

Cheatzy is designed to avoid this effect.

Since it is an active device, the real current consumption is constantly monitored, so, for safety, if it reaches a limit value for a certain time, the real current value will be sent to the BMS, so that the BMS can react by activating the warnings and overcurrent protections of the system.
You can also decide wether to enable or not cheating even during charging/reku, in order to preserve your SOH from unmotivated / premature degradation.
The cheating factor is fully customizable, simply by moving the dip-switches on the device, in order to adapt it to the SOH of your BMS.
Once opened the battery, the installation is plug & play: unplug the current sensor connector and connect Cheatzy.

I would be happy if someone else could test the device.
I have the components to build 5 more units.
Since I consider them as "test units", I ask 80 euros + shipping costs each, with a return policy condition: if you are not satisfied with the device I'll refund you.

That's it, and please remind it's an hobby project, so if you join it you do it at your own risk, because I take no responsability for damage or other issues arising from its use.

Thanks to Berthold and euver for the original idea of working on the current sensor to cheat the BMS, to Snorre for testing the very first prototype which gave uncertain results and for the enlightening insights to improve its functioning, and to Miata for lending me his 39% SOHed BMS, subjected to my extreme tests.

Some photos of the device:
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Aktuell nutze ich ja den Bypass um den Reservekanister Effekt zu reduzieren. Leider ist, wenn das BMS eine niedrige SOH gespeichert hat, der Effekt immernoch da. Würde daher für hartnäckige Fälle gern mal dein Gerät ausprobieren.

Die Alternative wäre ja das neue BMS, welches Plug and Play passt, aber ein Vielfaches kostet

Jack-Lee schrieb: Würde daher für hartnäckige Fälle gern mal dein Gerät ausprobieren.

It's no clear to me: do you want one?

Yes, i would test one.

Basic instructions for setting the cheating factor.
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If you are unsure about the exact capacity of the new battery, I suggest to round up a little more.

Still can i get one?
Jan 12th, i bought used 2020 Twizy that only ODO 540km, now 700km
I am considering the battery cell change to Calb 218Ah
Could you ship to S Korea? Please let me know

Yes, shipping to South Korea is possible.

Great!, What kinds of payment comfortable for you?
Please let me know.

I’m happy to announce I'm developing a future alternative version of the Cheatzy, with Bluetooth connection capabilities and additional features.
It will be possible to perform adjustuments on cheating factor values without having to worry about opening the battery case, if needed.
In order to do so, I coded a new mobile Android application, composed by two main pages: one is used for data input and output
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and the second one for BT settings and cheating factor automatic calculation.
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You will be able to read parameters and also overwrite them connecting via Bluetooth to a suitable already-paired Cheatzy device (can store up to five Cheatzy if you have more than one).
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Last but not least with this Cheatzy version, you will be able (if you want) to use a different current sensor instead of the original one.
Specifing parameters of the new current sensor in the “Sensor settings” tab, Cheatzy will make it compatible with the original BMS.
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This is an useful function if you want to replace a broken original sensor with a cheaper and more available one.

Hello Delvecchio,

I love this idea!
Why didn't anyone think of this before?

I'm currently developing my setup and would like to create a battery kit using a Cheatzy.
www.twizy-forum.de/Alternativ-Akku/92110-eine-andere-batteriekonfiguration#268475
Could you sell me one, please?

Sure.
During Easter, De Paul shared here his positive experience with this device, but unfortunatly the post got lost for a forum hacking attempt.