# Anyone have experience w/ Peter Perkins BMS?



## Overlander23 (Jun 15, 2009)

Subject asks it all...

The BMS description and info can be found here: http://www.batteryvehiclesociety.org.uk/forums/viewtopic.php?t=1245<br

The design uses per cell MCUs which communicate with a master. I was wondering how it was doing in the real-world, ie with electrical noise, etc...

What are the chances of the design killing a cell, inadvertently. And do the individual MCUs get their power from the cells, or from a master source? If not the later, can it be modified to draw a logic source from an external supply, so as not to tax the cells all the time?

Thanks for any help!


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## MN Driver (Sep 29, 2009)

I've read through the information on that BMS and seen his videos of the display showing the Ah count, temperature, SOC, amps going in and out, difference between cells, individual cell voltages, etc. that it shows along with the wireless setup where he can see watch the progress of the battery pack charging from inside the house too. It's a pretty sweet setup and if you know how to source components at good prices, it would be a pretty sweet piece of instrumentation to have. It takes care of issues such as spaghetti wiring a pack with HV since it uses serial communication instead to communicate all of the data around. You could ask Peter Perkins these questions or post them in the thread you referenced. He hasn't had any issues with his BMS for the three battery packs he has built it for. Reading through his thread will tell you how it communicates and how it receives its power and how much power the BMS consumes.


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## illuminateddan (Dec 19, 2009)

Hi,

I'm currently using his slave modules (the single unit per cell type) for my BMS but I'm designing my own controller based around an Arduino mega. The slave boards are great, I managed to get 45 boards printed for about $400 AUD, and then the component can be sourced cheaply via digikey, farnell and rs and of course ebay. 
I know that he had a few noise issues on the serial bus but he fixed these up with a varistor across his serial bus and a pull down resistor. I'm a big fan of the slaves and am currently modifying the code to make them do more (a slave serial bus as well as a master bus). The picaxe chips are super easy to program and are far easier to get involved with than straight pic chips. 
If you're up for the effort and the learning curve, this is a super system and is really well documented on the BVS forum, although you really should spend the time and read through all the posts (200 pages ish!!) to get the most. Half the time you can just skim it and read only peters posts.

Hope this helps,

Dan


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## Overlander23 (Jun 15, 2009)

Thanks for the responses... I'm currently muddling my way through the multitude of posts.

I notice that two versions of lave exist, one that is a per cell slave, and a larger multi-slave board. Do these essentially operate the same? Or can one of the solutions work with a common power bus so that the slaves are not draining all the time power the slave MCUs?


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## illuminateddan (Dec 19, 2009)

The two systems are essentially the same but the central organised unit has all the slave modules in one place and then runs wires to each cell. The data buses are the only common bus on these units.

The slaves cannot be powered by common power because of the way they work (which is using a voltage reference diode connected to the processors ADC, and deducing the supply voltage from the ADC reading of a known voltage.)

The power drain per cell slave is very very small, in the range of micro amps when the cell is in standby.


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