What is the temperature range for HV Battery

For your question there is an answer from Hybrid Assistant: The same as every hsd: up to 36°C is ok, from 36 to 46 the fan is activated by the car and the recharge/ discharge threshold are progressively decreased. Above 46 the recharge is very very low until disabling of the battery usage.

 

How can I check the temperture level for the HV Battriy for my prius 2008?

 

welcome!
scan gauge

 

or Torque Pro.

 

Update: still happening! Not very often through. I can still reproduce it by driving 25 mins home from work at freeway speeds (65mph), park for a bit, then drive down the big hill for a run in the flats.

I got the Dr Prius app that connects to my Carista OBD2 port and have been monitoring the batter temps. From the very short research I have done it seems like my battery temp is higher then usual.

Weather here is cool today, about 70 avg across my timeline.

Home from work, middle battery temp (temp 2 in my screen shots) is about 108. Drive to my running spot and park, battery gets up to 110.5 (mostly downhill, 2 miles max).

Park for 1.5 hours, battery temp is up to 126 from just sitting and it’s getting cooler out!

I just checked the fan filter and it was really clean. So my battery temp went from 110 to 126, after sitting for 1.5 hours in cool weather. What gives?!

First screen shot is when I parked before running, second is when I got in the car after 1.5 hour run. Pretty sure the high batter temp is my problem

 

The screenshots show a bit of imbalance but within specs, but it is clear your battery is not cooling adequately. How is the cabin temperature? Up in the 100ºF's+? If your cabin is cool and you have the A/C on keeping it at the mid to late 70's, I'd be looking at the cooling fan and making sure it was clean and functioning. If your car is heating up to extremely hot temps, I'd be looking at some way of mitigating that. For example, by parking in the shade, cracking the window a fraction, and using window shades.

BTW, your car is a Gen 3, you might better advice posting int the Gen 3 forums. Just because they look alike, doesn't mean they are the same.

 

Cabin is cool and fan does turn on by itself. Ac almost always on

Thanks for the heads up, did a google search and ended up here didn’t notice it wasn’t gen 3. Thanks!


iPhone ?

 

I'm curious as to why every screen capture shows SOC in the high 70s?

Are your temp problems only occurring after the long downhill?

I'm thinking those temps may be due to the significant regen you're putting into the battery to the point of 77% SOC, and then just turning the car off to go take a run. The heat put into the battery is not going to be immediately seen by the thermisters. The Gen 3s have the thermisters mounted on the tops of three modules. One on the driver side, one in the middle and one on the passenger side tucked into small recesses in the modules. Cabin air is blown into the bottom of the battery, up between the modules and then out the exhaust duct. You're throwing a lot of regen into the modules, creating internal heat, then turning the fan off before it can really cool them down again. As it sits, the heat in the center is just radiating outward toward the sensors. The center of the module pack is always the warmest, just nature of the beast. Still, I don't those temps are high enough to even kick the fan into speed #6.

There's always other possibilities:

1. Is the air supply vent clear of interference?
2. Has the fan blown dust/dirt/dog fur/debris/small children into the bottom plenum where it may be clogging passages between batteries?

 

Yes that was after the 1.5ish miles downhill, battery status showed 1 blip shy of full at that point and sometimes down that hill it’s always full.

It only seems to happen after a downhill drive (I live up the hill, everywhere is downhill) so makes sense that the battery is warming up and then doesn’t have time to cool down with the fan.

Ive checked the filter religiously and it’s never dirty, I have an appointment with a service advisor at Toyota tomorrow so I’ll see what they say. Then I’ll tear up the back seat/ boot to get to the fan and see if I can find anything.

Maybe it’s normal behavior? Just started happening since I moved atop the giant hill.


iPhone ?

 

Its called heat soak. The inside battery's are pretty hot and when you shut the car off the fan stops so its just basically baking in the battery box. And all the modules heat contribute to a higher temp till they eventually cool down.

Toyota probably tinkered with an idea of leaving the hybrid fan on for an interval after shut off for hybrid battery cool down after shut down but that's hard on the little 12 volt battery. It would have greatly increased the hybrid battery's life though instead of letting it bake. Maybe they do that on a G3 and beyond?
Lots of cars leave the rad fan on for a while after shut down to cool the engine.

heat soak Same thing happens to the inverter coolant on a G2. It runs 75 degrees cooler than the engine coolant during op but after shut down since the rad and the inverter coolant are in the same metal box the rad it quickly absorbs the engine temp and gets real hot after shut down.

Toyota fixed that on the G3 and beyond with a separate rad for the inverter coolant no more engine heat soak.

 

I have a Scangauge II. I’ve been monitoring BF2 (Battery Fan #2) and BT2
(Battery Temperature #2).

Outside Temperature has not been that hot
70s -80s.

BF2 at 4 and BT2 at 114-117.

Granted my Prius has over 200k miles.

Noticing Hybrid battery has been hotter , doesn’t seem to be cooling down much and the fan running at 4 which is on the high end.

Have no idea what is going on. Any insight on the matter is greatly appreciated. Thanks.

 

Is this a lot of stop-and-go, running AC? Or easy highway driving? Have you checked the fan for lint build-up?

FWIW: with SG I was seeing 35C (95F), cool evening, car fully warmed, on 80 km/h (50 mph) limit, quiet highway. Fan speed 1 or 2.

 

Fan was just cleaned by Toyota service. I did drive the freeway later that night for about 25 miles. temperature down to 60-65.

the fan and hybrid battery temperature did drop all the way down to BFM 0, BTM 91 degrees.

with constant cool airflow at freeway speeds, glad this part was as expected.

driving around town was my problem. Even at cooler outside temperatures, the battery was constantly at BFM 4 BTM 114-117 degrees. It’s like the hybrid battery compartment is constantly hot and not dissipating the heat when not getting the rush of cool air at freeway speeds.

 

I'm wondering now about how does a Prius Hybrid System respond to a situation where the interior temp of the car is at, or exceeds, HV Battery operating temp BEFORE you even start the car?

 

Ive been watching Dr Prius app and connecting it before I fully start the Prius. I've seen several times on a 100f day that the battery temps were 130f before the car was started. I think 130ish was as high as I've seen it so far but it's not uncommon for interiors to get well over 150f. At 130f I didn't really notice any difference in how the car was driving. I turned the AC on high and had Dr Prius running the hybrid fan on high and it got down to around 115 after about 15 minutes. I wish I could program the hybrid fan to just run on high all the time. I'm sure it would be very beneficial to have dark tint to help the interior not get so hot. Cracking the windows also helps, but sometimes I forget to do that.