What is the 'Bcm Replacer' and why do I need it?
A good question and one that is quite tricky to answer.
If your happy with the old Nimh battery tech, and the way the OEM Bcm manages the pack and reports information etc, then you don't need a 'Bcm Replacer'.. The OEM Bcm does a pretty good job of looking after stock packs, and has been proven over nearly 20 years.
If you are not happy with the above, like lots of information, have some good technical skills, and want to consider alternative battery chemistries, bigger batteries, higher voltage batteries etc, then the OEM Bcm is not ideal. It's not configurable by us the end users, and it's inner workings in parts are still shrouded in mystery. It's very limited in its ability to directly deal with larger capacity packs and or higher/lower voltages... It's reporting and monitoring capabilities are very limited, restricting information about our battery and IMA system condition..
Enter the 'Bcm Replacer' an OEM Bcm replacement, designed by long term Insight owners and enthusiasts RetepSnikrep & BullDog for the benefit of our cars, us the owners and drivers, and the wider Insight community..
If you have been following this thread you will know the 'Bcm Replacer' can mimic the functions of the OEM Bcm and has extensive reporting and control functionality. Including a video screen and keypad etc. It can interface with a commercial Lithium Orion2 Bms, and allow installation and monitoring of larger, higher voltage Lithium battery packs. It can also provide basic tap voltage deviation monitoring for batteries that don't have an independent Bms. It has a number of safety mechanisms and can compare and check information to report problems promptly to the driver.
It replaces the earlier 'Bcm Interceptor' when using Lithium packs and gives much greater functionality.
In short the 'Bcm Replacer' is a bridge or stepping stone between our old Nimh battery technology and the new world of Lithium and beyond. It will help to keep our cars on the road, and gives us flexibility in our battery choices. It removes the monkey on our back that has kept us in the past and mainly shackled to Nimh packs..
If you want to participate or just lurk that's great, enjoy the ride.
The project would not have been possible without help and knowledge from many owners and enthusiasts on here over the years.
So our grateful thanks goes to them, they know who they are.
Of course if we hadn't had the internet and this forum, none of this would have happened, and we would never had heard of each other. We would in all likelihood be limping along individually with our cars and the quirky problems they present.
RetepSnikrep & BullDog
The above was added to bring the first post uptodate, the original first post is below.
I've started this thread to document/discuss a fake/alternative BCM project to allow different battery chemistries in the Insight MK1 whilst eliminating the three bar soc bug, and allowing the gauge cluster to operate correctly.
This project will draw heavily on what we have learnt in the BCM/MCM analysis thread. https://www.insightcentral.net/forum...m-signals.html
I would like to design something that sits between the BCM & MCM intercepting the data from the BCM, modifying it with our own batteries current soc/temp etc before sending it on to the MCM.
Knowing me it will be based on 2 Picaxe chips probably 28X2 with 2 rs485 interface channels.
One rs485 chip and 28X2 listening to the BATSCII bus from the BCM.
One rs485 chip and 28X2 transmitting on the BATSCII bus to the MCM.
I think we should retain the old BCM and just intercept the signals between it and the MCM on the BATTSCI bus, modifying them as reqd. This would potentially be quite simple, allowing use of the stock BCM for the current, temp, voltage data gathering it does now.
No fancy connector problems. Hmm!?
Should it include a cut down version of my BMS to manage the new battery?
Should it include the suplementary dash display to give the user the extra battery data?
Please chip in with ideas etc.