Scanguage command to turn on hv battery cooling fan

I know the battery fan can be controlled with Techstream. I'll see if I can dig out the control sequence used the next time I have the spare time.

 

I'm designing a control board that will turn on the fan with a price point around $30. Since I installed the prototype on my 2005, the battery temp has not been more than 104 degrees. I'm also designing a more complex board that you can connect your laptop to via USB to control and monitor the fan along with a few other things. Look for a post from me later on today with some pictures. If you haven't seen this thread, take a look:

Using the battery cooling fan to cool the car and the HV battery | PriusChat

I'm also going to include the temperature hack on this board as well.

 

The CAN message to set the Gen2 battery fan speed is

00 00 07 e3 30 81 00 0n .... where "n" is 0,1,2,3,4,5,6

The reply is

00 00 07 eb 70 81

An "n" of zero is apparently normal mode, where 1-6 are override to speeds 1 through 6.

I haven't tested this with a Scangauge yet, so there may be more to setting it all up. Even if it does work, I'd be cautious about setting the speed manually to anything less than 6 and just leaving it there. If you set it to something like 3, when the automatic process would call for a higher speed, then you could provoke undercooling.

I'll write a Scangauge procedure to implement these codes in a few days. It could also be implemented for ELM.

 

Thanks RobH! Knowing the command and response, I can help with the coding if you don't mind.

	Column 1	Column 2	Column 3	Column 4	Column 5	Column 6	Column 7
0	[TH]XGAUGE[/TH][TH]TXD[/TH][TH]RXF[/TH][TH]RXD[/TH][TH]MTH[/TH][TH]NAM[/TH][TH]Notes[/TH]
1	[TR][TD]Set Battery Cooling Fan Speed[/TD][TD]07E33081000n[/TD][TD]02EB24700581[/TD][TD]1901[/TD][TD]000100010000[/TD][TD1]SFS[/TD1][TD]where n is 0	1	2	3	4	5	6 (6 is max) shows ON when set[/TD][/TR]

	Column 1
0	[TH]Name[/TH][TH]ShortName[/TH][TH]ModeAndPID[/TH][TH]Equation[/TH][TH]Min Value[/TH][TH]Max Value[/TH][TH]Units[/TH][TH]Header[/TH]
1	[TR][TD]Set Battery Cooling Fan Speed[/TD][TD1]SFSn[/TD1][TD1]3081000n[/TD1][TD1]A[/TD1][TD1]0[/TD1][TD1]0[/TD1][TD1]No reply required[/TD1][TD1]7E3[/TD1][/TR]

Vincent

 

Awesome dude! I tried this on my way to work this morning and it works perfectly! Is it just me or has everyone missed this SC command up until now?

While this issue will solve the hot battery issue while driving but doesn't solve it after the car is off, which can be a real problem:

Update on battery blower control board - Wanting to include the kitchen sink | PriusChat

 

Adrian Black added this to his Gen III SGII spreadsheet a few months ago. I have tried it to set the fan speeds for testing fan voltage, etc. I have not tried to set it to a set fan speed mode and leave it there though. I am a little skeptical of trying that. Another member reported setting his at max speed, Mode 6, and leaving it there and keeping his battery temp in the 80 degree range.

 

Why are you skeptical? What's the downfall? The command only works when it's one of the four gauges monitored in real time on the SC. Once you put a different gauge on the SC, the fan reverts back to normal operation.

I'm willing to guess that ~99% of the people who want to use this command monitor battery temperature as part of their daily driving habit. If you're monitoring battery temperature and wanting to control the fan, it's because you don't want your battery to exceed a certain temperature and you are always cognizant of that.

I think this is a great addition to the SC commands. And, it will make my job easier in making a control board for when the car is off.

 

I am only skeptical of running it continuously and shortening the life of the fan. With the 6 speed settings it is obvious that the fan was not made to run at a high speed continuously. With temperatures in the 100F range today I may set the fan to run continuously and see if I can get the battery temps cooler.

 

A new fan can be bought for ~$100? (never priced a new one but used ones are ~$40 on E-bay). A new battery can be bought for ~$2500. I would consider this - Gen II's that run in the Southwestern US probably have the battery fans running more than 80% of the time. My battery is on its way out now and even when temps are 70 degrees, the fan will run hotter than 105 degrees. I need to keep the fan on to keep the battery temperature below 100 degrees.

 

Has anyone else tried levels 1-4? Levels 5 and 6 work fine with the SC for me (I get the word "ON" and the fan comes on) but the fan doesn't work in levels 1-4.

 

Good point on the price of a battery fan versus the HV battery. Even at 100F now the battery fan control does a decent job of keeping the battery temps in control until I start doing a lot of start/stop driving with a lot of regen and restarts. Even now the battery modes are in the 1-3 range. I am not seeing any 4-6 mode ranges yet. If I start seeing the speeds get up in the 5-6 range or the battery temps get too high without dropping once I get to steady-state driving I may look at setting the speeds manually.

I tried all of the levels 1-6 when I was testing. I remember having to change back to 0 and then try again a couple of times to get it to set some of the modes correctly.

 

I think this may have been a flaw when Toyota was designing the OEM battery fan operation. It may be the case where under normal operation the battery fan will cool the HV battery when the battery is new. However, as the battery ages, it gets hotter and stays hotter longer.

In other words, Toyota designed the fan to come on when the battery is at temperature X (calcuating A/C usage, cabin temp, OAT, etc) and through their testing they noticed that the battery temperature will be reduced or stay at temperature X. Maybe they didn't incorporate calculations for an older battery. I can say with 100% certainty that if I leave the cooling of the battery to the OEM battery control fan, it will get hot and stay hot. My CCL will be reduced to <20A and my engine will run almost 100% of the time.

Like I said, everything is working as intended in my car. The problem is my aging battery (2005 with 173K miles). I see a significant difference between the way my car operates this summer compared to last summer. Between June 2011 and today I put 45K miles on my car. I have 30 Gen II cells sitting in my bedroom and I will start balancing them next week. With one charger, it will take ~45 days or so to get them all balanced. I'm really curious to see how the OEM battery fan control will work when I compare the 8 year old 173K mile cells I have in there now to the 6 year old 60K mile cells I will be balancing. My guess is that the battery won't get as hot.

*This post is strictly my opinion as I have not seen a software specification for the OEM battery fan control operation*

 

It will be interesting to see how the newer batteries do as far as temp versus your existing ones. Keep us posted.

 

Do you mean the display showed "ON" and the fan didn't spin or it showed "OFF"?

Here is another Xgauge to show the fan speed:

	Column 1	Column 2
0	[TH]XGAUGE[/TH][TH]TXD[/TH][TH]RXF[/TH][TH]RXD[/TH][TH]MTH[/TH][TH]NAM[/TH][TH]Notes[/TH]
1	[TR][TD]COOLING FAN SPD[/TD][TD]07E321CF[/TD][TD]010702EB0321[/TD][TD]3808[/TD][TD]000100010000[/TD][TD1]BFM[/TD1][TD]Stopped: 0	Low to high speed actuation: 1 to 6[/TD][/TR]

Vincent

Edit: You need SGII firmware ver. 4 and above to run this.

 

I have 4.06. When I tried 1-4, the fan never spun and the SC never showed the word "ON." When I go to speeds five and six, the word "ON" comes on within a second or two followed by the fan, spools up slowly about 8-10 seconds later.

 

Just got my HV battery fan speed working with my Dionomite Mega. It was not quite the same as shown by RobH above. Using the above info I could not get it to work. So I used my Duinomite Mega to spy on my VCI chinese clone mongoose cable using Techstream software. See photos.

The PID I found to work is

7E3 04 30 81 06 0n ...................... n - 1 to 6 (fan speed setting)

The return frame is

7EB 02 70 81

The interesting part is when using this PID is that if you stop sending the PID the HV battery fan turns off regardless. So if you assume that you only have to send the PID once you are wrong. It has to be sent periodically about every half second (timing guestimation).

My Duinomite Mega Canview V4 equivalent Project | Page 6 | PriusChat

 

I can certainly see the need to modify cooling when the car is shut down sitting in the heat. However, when I operate my vehicle, I run the air conditioning, believing that even if I can manage without the cool air, it is needed for intake to the battery fan. If 75 to 80 degree air is going into the battery, shouldn't that be sufficient for all operational cooling needs, even with an old battery (which mine MORE than qualifies as - 195K miles and 8 years)?

 

The HV battery fan modification is meant for a Prius with a aftermarket PHEV kit installed. A normal Prius does not need a HV battery fan modification regardless of how old the battery is.

 

The J2534 data that I recorded filters out what I guess is a length byte (04/02 in these sequences). J2534 combines multiframe data into a single sequence.