BCM Gauge V2 Batery Data Display & Control

[retepsnikrep]

I think it's time to start discussion of V2 of the BCM gauge. This is the new thread for it. My proposal for the new gauge is to retain all the present features, but add a few new nice ones.

It won't be much more difficult to assemble or install. It will only have half a dozen extra components and a few more connectors. It will be able to use the current pic 12F683 (possibly with the current software) or the new enhanced pic 12F1840 with double the memory and the extra software functions. It will use the same 16x2 serial lcd.

The new proposed functions/connections will be.

1) 12v relay driver output connector.
2) Battery fan output connector. (Possibly)
3) Combined lcd/switch output connector.
3a) Reduced resistor count for switch so it does not need the seperate pcb.
4) BCM power output connector. So BCM and Gauge can be powered during charging.
5) 12V input connector. For 12v wall wart supply during charging.


6) BATTSCI output connector.

No 6 is the main one! And if you havent guessed the significance of it already, it means the board will have an extra rs485 comms chip and be able to perform the full BCM interceptor functions. It will sit in between the BCM and MCM, and rather than just listening to the data, it will have the ability to manipulate it to our advantage.

How you ask, well.

It can enable/disable assist or regen. (Like the clutch switch function, but also applicable to CVT cars)
It can request regen. Like low soc forced charging
It can overide temp, soc, volts, current etc etc
It can overide IMA codes

For those with parallel packs it could fake the soc to maintain IMA performance until a true low cell indication is recd so you never see the 3 bar bug again. I'm sure more is yet to be discovered within the BCM data but it needs members help to do this.

Any comments and or feature requests please post on this thread.

Here is a quick look at BCM Gauge V2 schematic. Please point out any glaring errors!!

www.solarvan.co.uk/Gauge/BCMGaugeV2.jpg

FYI Peter

PS It will be available worldwide.

[Eli]

Peter, I will happily send you one of these samples of the PIC12F1840. I think it would be highly advantageous to use this PIC in future small projects like the BCM Gauge V2, as it seems memory constraints are a huge hold back.

[retepsnikrep]

I'm looking for an exclusive US/Canada distributor for the pcb boards for this project. I will supply them in bulk say 20-30 to you, and you then send them out to purchasers. I will pay the distributor $10 per pcb they send out. Local postage comes out of your $10. It's too expensive and time consuming to send them out individually from over here PM me if you have a good post history on here and wish to be the distributor.

Like Mike I don't want to get stuck with a lot of pcb's so I won't be ordering any until I get at least a minimum 30 confirmed payments and orders. Price will be ~$50 for the pcb and software will be via download. Postage etc is $10 on top of that. You will need the pic programmer. There will be no kits or pre-programmed pics unless the US distributor decides to offer that service. Estimated parts cost ~$10 excluding 16x2 serial lcd which a lot will have anyway.

Yes it's more expensive than V1, but it has more functions and the price helps to fund my further research into both the MK1 Insight and MK1 Civic, which i am looking at the moment.

If you want to pre-order one send me $60 if you live in the US/Canada which includes distribution and postage. If you live anywhere else send me £36.00 which also includes postage etc. paypal only to peter@solarvan.gotadsl.co.uk

Note I won't order any pcb's until we pass the 30 pcb confirmed order mark. Payments are non refundable unless I cancel the project due to lack of interest/orders in which case I will refund you. If we haven't passed the minimum order level within 6 months I'll cancel it. Peter

[madmanmostafa]

If yours can do all that you say it can, like override IMA codes, then I'm in. Also, I could be a west coast distributor, but we can talk about that. I have lots of space out here as wel.

Also, by override, you mean that if it's not regenning because it's out of balance, you can Force a regen, and Continually force it to regen (similar to MIMA) to rebalance the pack without having to stop and plug it in?

[Eli]

Unfortunately, you can't really balance the pack with the car's electronics.

[retepsnikrep]

Correct you can force it to regen so you could possibly force it to balance.

With the cars electronics you can force it to assist/regen as we know, with the new BCM gauge you can overide any factors you want. So it would be possible to continue to regen at low current ignoring the soc and voltage.

So i disgree with Eli it may be possible to balance the pack by overiding the BCM.

[madmanmostafa]

Originally Posted by retepsnikrep

Correct you can force it to regen so you could possibly force it to balance.

With the cars electronics you can force it to assist/regen as we know, with the new BCM gauge you can overide any factors you want. So it would be possible to continue to regen at low current ignoring the soc and voltage.

So i disgree with Eli it may be possible to balance the pack by overiding the BCM.

That's pretty amazing. What about using this BCM Gauge with a MIMA system? Would it possibly interfere with any of the original IMA functions if you force a regen?

[retepsnikrep]

The beauty of Mikes MIMA and my current IMA Control is that it can't overide the BCM safeties, so you can use it with impunity pretty much, and exercise the pack up and down within the bcm limits.

However the new BCM gauge can overide any BCM data or IMA codes, so can take the BCM and battery outside it's comfort zone.

For instance the BCM data could be altered to report a slightly lower voltage or soc. This would enable charging to continue past the normal limits. Temperature and ptc strip data can still be analysed/used though to prevent meltdown. Theoretically if you continue to charge the pack then yes it would start to balance once the first cell is full. If you limited the charge to ~350ma then you would have to drive around for a very long time to balance the pack. If you charged at a higher rate say 3.5A then it might only take an hour or so to balance them, but the cells would disipate a lot of heat. So fan would need to be on full at all time during such a balance drive.

It's much more effcient to do a balance charge with an external charger like Mike's forthcoming highly developed unit which I recommend to anyone serious about keeping there car on the road long term.

The software for the new BCM gauge will simply be a development of the current code with extra sections for overriding the BCM data. I'll prevent people going to far and ensure that the temp/ptc data has the final say.

[madmanmostafa]

I imagine putting them on a 3.5A charge would put a serious load on the car.

I'm just wondering if say I'm on a trip, the IMA light comes on, the battery stops charging/giving assist, I could Force it using your gauge to charge anyway? If that's the case, that's incredible!

I'm actually putting together the funds for a grid charger.

Regarding it charging at 3.5A and getting hot, that was actually my next question. Which brings me to my final question. You said you download the software. Does that mean you will be updating the software? And when you update, do you need to take the device out of the car? I'm curious if you could leave the thing in the car and hook it up to the computer and run diagnostic software. It could be a fantastic way to accurately log routes, charge rates, etc, using a GPS and logging software to maximize gas economy. It would also help with recognizing trends in failing devices.

[retepsnikrep]

You need to take the time to read the first BCM gauge thread.

3.5A is not a serious load

You could possibly force it to charge depends which IMA code is present. If it's battery/cell overheating obviously that would be a bad idea.