John and I have been working hard on making modifications to the core EV Dashboard system to allow an integration to the Hardy Flex BMS.
This discussion thread is intended to describe the integration issues and system development progress.
As of Jan 28, we've taken our first highway trip with the EVD and Hardy BMS!
while not a monumentus ocassion, it does prove out a couple of things:
1) The bluetooth communications is (at least for this EV) is EV tolerant. All the communications are logged, and a cursary review says that there were no missed messages or CRC errors. This is excellent news.
2) The Hardy BMS can be recoded to be stimulated remotely and have a separate User Interface. This was a challenge.
3) The EVD Display rocks. I've not seen anything as user friendly, simple, yet complete in an EV before.
- The Display Rocks
- BT comms in an EV seems to be rock solid.
- Software infrastructure is nicely laid out for integration with several types of BMSs.
Power: The IOGear BT has is powered by the BMS. The IOGear has a power fluxuation from 2 to 250 ma. about every 1.5 seconds. (I don't understand enuf about BT to know why, but it probably doesn't matter. )The power
surges are causing mis-readings on the current sensor -- both the current sensor and AtoD PIC need a stable power source. The internals of the BMS have two different power sources, may need to strengthen the main
power source or switch the current sensor to the aux source. I think this is solveable.
Price: The display is about $100 and the IOgear BT (is about as cheap as they come ) is about $70. Would be nice to find an RS-232 to BT solution for cheaper. This will set a 48 cell BMS in the $1000- $1200 range. But you get
a nice GPS with it too.
Software: Still need more work on the Software in the area of battery display, user alerts, and configuation settings.