Upper two battery packs removed

The body is removed and now the battery packs can be disconnected. Every pack has two wires attached which connect all 4 packs in series.in total there are 100 cells (3,7V) which results in a voltage of 375V. .

DC voltage of battery packs

DC voltage of battery packs

After the wires and the fiber cables where removed I lifted the packs with a forklift. the motor is mounted on to the original Lotus (Toyota) gearbox. The motor is on the right side under the black round cover.

Battery packs removed

Battery packs removed


Recently the car wouldn’t start charging and Error Code 5 started showing up. It started intermittently and could be solved by unplugging and plugging the charge cable. Last week it wouldn’t charge at all. The cause of the problem is known, a kind of Pertinax (phenol formaldehyde) is used as isolator between the rotor and the flywheel, when Pertinax ages or gets damaged it gets hygroscopic. To replace te bad isolation the body shell and two battery packs need to be removed from the car.

Error code 5


Build a LOM interface

AC-Propulsion offers a LOM (Lithium Optical Monitor) diagnostic interface. This interface enables you to diagnose one or more LOM modules. I used this interface, which I borrowed, when I replaced a bad cell from the battery pack (see my other post).

AC-Propulsion LOM interface

Original AC-Propulsion LOM interface

The original interface is based on a CP2102 USB to serial chip, one Single Bilateral Analog Switch and a few transistors and resistors. The blue and black plastic connectors are from Industrial Fiber Optics (IF-E96E and IF-D91). I draw the schematic based on the original Interface and replaced the SMD components with normal sized components. I couldn’t find the DIL version of the SMD bidirectional binary switch (SN74LVC1G66DBVR) so I used the 4066 a Quad Bilateral Analog Switch. To prevent problems with the CP2102 chip I ordered a standard Micro USB to UART TTL Module 6Pin Serial Converter.

Lom interface v1.0

LOM interface v1.0