Decoding CAN messages 0x348 & 0x3C8 as described by pEEF

Many, many thanks! Here's a link to a Google translated version:
Google Translate

I'll dig into this document today - can't wait

Update: I couldn't wait and started reading this at work. Yuck - Google translate messes up quite a lot of stuff with bit masks etc. But, hey, Google's French is better than mine. And kinetik's English is way better still

 

Just found this thread.....Yay.

 

Different model year...

 

You dont have canview installed?
Because then you now about the ice spinning

-Htc Tapatalk

 

I own an 2005 Prius with an Enginer that I'd like to frankenstein with about 8kwh more battery and EV-mode spoofing. Is there an executive summary anywhere of what's scattered throughout these threads? I don't want to re-invent if the knowledge is out there.

Thanks,
-Bruce

 

So... maybe I can kick this off:

The "Big Rocks" for this project:

- Remove the OEM battery, it's just going to confuse everything and it's too small
- Interupt 0x348 and 0x3C8 messages going to the ICU ECU and hijack the engine run modes in favor of the "stealth" EV.

Battery:
- Build a battery ECU (Arduino+Can-Bus Shield) that can send the information the rest of the car (mostly HV ECU) wants.
- Build a 192-volt 7kwh battery pack from 40Ah LiFePO4
- Make a PFC charger, I like EMW project.
- Connect the 48-volt Enginer (4kw) batteries in series with the one above
- Install regulators
Total cost: ~5k + old Enginer (boat anchor from my perspective)

I'm confident I know how to get all that done, but I'm concerned about fail safes, over-speed, over/under-temp, etc?

BTW; I'm a big fan of simplicity, I don't need/want any kind of display. This is my wife's car, if she has to touch a button or it goes into error-state, this is a total failure. Ideally, I should program the ECUs to fail gracefully into whichever mode makes most sense without feedback.

Anyone, help?!

 

Hi Bruce,

You can check out this thread as well: YAPiP - recreating pEEf's approach | PriusChat

I believe your approach will work with a couple of exceptions - it won't allow highway speeds in EV only mode and it may still burn gas. The HV ECU will switch on the ICE to keep the speeds of MG1 & MG2 within operating range. If that doesn't matter to you then I think you have the right approach. You may still burn some gas though because of engine warmup.

The trick for EV only and highway speeds (MG2 apparently has enough grunt to push the Prius at ~70mph) is to split the ECM (also known as the ICE ECU) onto it's own separate bus. To do that, seeing as you're replacing the battery ECU, it makes sense to make the bECU do the job of acting as a bridge. With the ice ECU on it's own bus you can intercept messages between HV ECU and ICE ECU and control the warm up and engine rotation speed. That way you can stop using any gas if you know your trip distance is less than your current EV range capability.

As far as your budget goes - I agree with it. I'm guessing $5K to $6K for my project. A couple of things:

1) If you go with the two buses then you'll need a device that supports 2 separate CAN ports. At one point my brother was going to design one of those for the Arduino platform. However, I decided to go with an Atmel DEV board that has everything and the kitchen sink on it. I agree that the final solution should be "so easy my granny can use it" (no offense to the technically savvy grandmas out there!). However, during the research & development it's a cool tool to have at my disposal. Especially now that I've got it working! ;-)

2) I think your pack voltage is too low. I'm planning on a 72 cell x 40Ah LiFePO4 pack.

3) What are the regulators for? Are they because of your lower pack voltage?

4) You don't mention it but if you want a "plug and forget" system then you'll need a BMS for that pack as well.

Read through the thread I posted above and let me know what you think. I'm especially interested in your point of view about "simple usage". The conundrum is when the trip is short and moderate accel (sure it can get to 70mph but how well will it merge?) then I want EV only. If it's faster or longer then I'll need ICE. Here comes the conundrum - when do I "automagically" tell the ICE to warm up?

All the best.
John H.

 

First... awesome post! Exactly what I needed.

Ahh, but remember I'm savaging the Enginer 48v pack, so in series, I'll get 240v nom, 260v max. The 4kwh Enginer is 83ah, I'll be leaving some colombs on them, but they are available.

top balancing shunts, standard stuff

Here where my thoughts. Most importantly, I don't want to "out think it" especially on my first try. I want a simple trigger, when you really need engine power, fire up the ICE. The stock Prius is hair triggered to ICE mode at about half throttle, it takes a Sunday driver (no offense to any Sunday drivers out there) to keep it EV. If I can, I'd like to make ICE mode work like the old "kick-down", you gotta floor it at 90% throttle for it to kick on, then once you're back into EV mode power requirements for a few seconds, kick it off again. Basically so long as there's electricity, assume I want to maximize EV .

From 100% SoC - 30% (MaxEV)
30% - 15% (MaxEV -> Legacy hybrid mode)
15% - 0% (Let the HV ECU call all the shots)

Does that make sense?

 

Yes, I have RFE. One idea is to leave the BMS and charger on and wire it on the AC side with the big charger for the main pack. I'd need 4-wire 240 (gotta have a common leg)... Most public chargers are 3-wire 240, so that makes a mess. The alternative is to wire the big charger to the whole 240v and somehow get shunts on those leads coming to the BMS (they are really small, so they would have to be small shunts). or... tare it appart.

Now if internally they are wired in 2-strings, then I can re-wire and double the voltage and get 96v-42ah, Which means I need fewer external batteries, which is awesome! Do yo know anything about that?

-Bruce

 

AT32UC3C-EK... $300!
Atmel Store / Atmel AT32UC3C-EK



So tell me, what's your brother up to?

 

In your YAPiP thread, you mensioned voltage. Also pEEF talked about them too (I can find the reference, but he's prolific). If I recall correctly, 260V is a magic number for Prius, if you go over that, it was behaving "jumpy". now the funny thing about LiFePO4 charge profiles, they have a wicked knee. And they need about 3.6v to balance well (you gotta get them volts up there), but that surface charge is _TINY_. They drop to 3.3v on the very first serious load. For example... My BMW is 44-3.2v TS. vNom: 144v, vEndOfCharge: 162v. On the very first corner after I pull out, it drops down to 145v and it doesn't go back up.

So if you really want to be tricky, you could play games with back-shunting bellow 260v, but really, charge is charge and it what's a few volts at 200 something? Target 260v end of charge or about 72 cells (see exact cell profiles), that should be right.

-Bruce

 

Ahhh (right back at ya) - I missed the putting them in series.

Yes, that makes sense - however, my concern is that if I go with the "kick-down" approach then I'll need a pre-warmed engine. I don't want to be abusing a cold engine with a request for lots of HP (plus it's already got 200K miles on it!) So, my conundrum is when to do the warmup. If I do warmup every time then I waste gas and get the worst emissions for no improvement. The easiest solution is a choice at start-up ask the driver:

"short trip" [EV Only]
"short trip + ice boosted acceleration" [EV normally, warm up ICE and provide ICE power when throttle > 90%]
"long trip" [EV usage per your above breakdown, warmup ICE, ICE provided power when throttle > 90%]

It will probably be better to use "load" rather than "throttle position" - or perhaps the two in combination.

 

You can pm - he's DaveAK on this forum.

However, let's just pretend that you need the horsepower of a Arduino Mega and that a two can solution is $100. You're now up to half the price of that kit. And that kit has a whole lot of other goodies on it . Once I get it all working how I want it (OK, *if*) then I might try and layout a board with just the pieces I need (i.e. no screen, just the CAN ports etc.). Then I can use that dev board for my next nefarious project (whatever that may be!)

 

Feed it in slowly, and maybe the kick down should be triggered lower, say 80%.