Can HV Battery Internal Resistance decline?

I don't know but the last few batteries I've looked at from 010 to 013 down to 04s seems that anytime you look at the battery you better move those covers across the nuts and plates and bus bars and have a look because they all of a sudden just bam get corroded in a 90-day period or something you go from no corrosion and then bam 4579 of the nuts are corroded banks three and six or whatever are showing no good whatever you get all the codes that show that and they'll correspond to the banks that the nuts are on and this happens just bam all of a sudden so it's like the corrosion resistance or whatever's not on the bus bars and nuts all of the sudden just takes hold or something

SM-A715F ?

 

Look at these few weeks ago copper colored and clean no leaks in car natt cover is whistle clean . ?? Car on ice only

SM-A715F ?

 

Time I replace bus bars possibly some cabling etc etc check all the sales replace four to six possibly I can get a complete brand new battery from Toyota with zero on it for like 1600 Dr is out w supply issues. The doctor sales look just like the ones on Alibaba around tubes replace your hole internals except for the computer different racking system it looks like etc but it all is made to fit in the original case I've been looking at these for a couple years but you can't order off Alibaba unless you're buying a shipping container full of stuff or close

SM-A715F ?

 

Last time I checked, temperature affects resistance- so I would expect seasonal shifts in ambient temps to reflect in IR readings.

Or another possibility is that the ecu reset somehow, as I recall that 19 milliohms is the default reading.

Posted via the PriusChat mobile app.

 

Yes resistance changes with temperature I even just read an article where Tesla cars get pretty terrible mileage and cold per se it's a big discussion about it over on teslarati. So I'm assuming in our low voltage Prius is as it may be resistance definitely will shift with temperature especially in the cold I think it's been stated before the folks can notice it that watch their batteries and apps a lot they will see it

SM-A715F ?

 

Yes, 19 is the default value if 12v power has been lost and restored. The displayed IR value will also change slightly with the temperature of the battery.

 

I have two years of data on my 2007 Prius with NewPriusBattery.com battery installed in July 2019. https://treecricket.com/vehiviz I pasted below Internal Resistance measurement dumps from short runs in each year.

Here is about a 20 minute dump from 2019.


Here is a bit over an hour dump from 2020

Here is about a 20 minute dump from 2021


As you can see, resistance varies during the drive as the conditions change.I haven't seen much difference due to temperature although most data is collected around 50s-90s farenheit.

New Prius Batteries might be slightly different than OEM batteries but not by much. The 0.019 ohms stated by others is not far off from the data here (from BAFX dongle and Torque Pro)

 

New is likely close to 19- maybe it was easier to code a default value vs having the data be "blank" until the ecu measured volts and amps then calculated actual IR.

Posted via the PriusChat mobile app.

 

Oh yeah. The cold 100 percent effects it. Havent you noticed how peppy your baby is 70 as opposed to even 40?