Nits: What is the mapping of the Pilot signal back to the charger. I suspect a controller handles the Time Of Day charging logic which means there should be a communication link to the charger. The BMS needs a communication link for TechStream to report the battery voltage and status. "Presence" should also be included. These control circuits are important but not addressed. Bob Wilson
I haven’t yet located the follow-on talking about the battery modules themselves; perhaps it hasn’t been published to YouTube yet...
2. I pretty much don't also know if tech stream would be able to access live data of the battery module voltages as in packs with MINH in some Prius gen2..
This video was uploaded on July 6 so the next one should follow soon. He produces excellent videos doesn't he.
The Weber State battery video about Prius Prime says two things that I think may be wrong: 1. Says that while charging the traction battery, the 12 volt battery is also being charged. 2. Says that by default the A/C compressor turns on to make cool air to cool the battery when the battery needs cooling during charging. Can anybody verify these statements?
I can’t personally confirm whether or not it charges the 12V, but by the reasoning stated (need it to run the cooling fans and climate control), that would certainly make a lot of sense. IIRC, he was not certain when he said that, by default, it does run the A/C to regulate battery temperature during charging. My interpretation is that he was referring to the Traction-Battery Cooler prompt, which, for some mysterious reason defaults to “no” rather than “yes.”
It is the prompt’s default to “no” that makes me think the default is no cooling. If cooling is good for the battery, I would expect the default would be to cool, unless the owner has a reason to prevent the cooling. When I check the voltage of my Prime’s 12 volt battery at the battery terminals under the hood, the readings are: Car off 12.45 volts. Car charging 12.62 volts. Car in Ready (on) 13.62 volts. In my Plug-in Prius the Ready and charging volts were the same, so I believed charging the traction battery charged the 12 volt battery. With the Prime, there is a one volt difference between charging and “car in Ready”. But there is a 0.17 volt difference between car off and car charging. Is it possible that different chargers, using different voltages, are used depending on whether the car is charging or in Ready?
As far as I can recall at least, even here in the Austin (TX) summer, I can’t recall it actually using the air conditioner while charging. I gather then that that’s more like “OK, I’ll use it if I have to,” as opposed to “I’m for-sure going to run the A/C.” It may not charge the 12V battery much if it’s just running the cooling fans and not the A/C.
Thanks for alerting us to that video. If you can remember, alert us to when "Part 2" comes out -- I'd love to see the next promised part, when he takes the battery unit apart...
I watched the whole thing. He does a nice job and explains things very well in the video. Will people be replacing individual cells in the Lithium batteries in the future? He doesn't advise it in the video.
I haven’t had a chance to watch but the first few minutes of this second one (yet!), but I think he said that the cells are all in series? That might necessitate being able to replace them individually. I’m guessing more likely in modules, though.
I learned a lot from watching this. First, the battery pack is really well engineered. Second, don't ever drive your Prius into water. I suspect a lot of bad things could happen before that 250 Amp fuse opened.
His/their videos about the mechanics are awesome too: Gen-1&2: Gen-4: Gen-3: I put the Gen-4 drive system video before Gen-3 above because, if you watch just two of these, I’d suggest it instead. However, if you want to watch all three, then I’d suggest watching then Prius generation order.
My stepdaughter originally bought a Prius C, but one sad evening while she slept, only a few months after she bought it, it got totaled in a flood. The good news, however, is that she got a regular gen-4 to replace it (better car!). The first video makes me wonder what’s below the battery? Perhaps I’m simply misjudging heights, but it doesn’t look like it takes up the entire height of the area behind the seat.
