I have a early 2001 (build date 06/00). It has 100K on it. I bought it broken, had to replace the HV ECU and a front wheel bearing. No codes or error light now. My biggest question is mileage. Weather is still cold, 20's and 30's. Sometimes 40's. I'm getting right around 40mpg. Most of my trip to work is interstate but I keep it at 55mph. Sound normal? Do have a scan gauge and I'm checking my low block. Almost always 5 and if not 5 its 10. I've also seen 2, 4, 9, and 19 very briefly. State of charge runs in the 60's most of the time. I've ran it down to 50 once using a very light foot on the gas in a shopping center. My pack showing its age? Could I get by replacing just block 5 and 10? Also will the Gen 1 with a good battery pack maintain 35 or 40mph on the flat with the engine off? At least till the state of charge drops? I've tried and can't hold mine without the ICE coming back on. Thanks! Gerry
The main thing to look for here is the voltage difference between the highest and lowest. If you can get that on your scan gauge, and then see if the divergence increases as SoC falls, you would have some indication of weakness in that block. A difference of more than 1.2V is a definite problem (generates a code?) while 0.2V or less indicates excellent health.
Looks like I can program in the highest and lowest voltage block readings. Will check that out! Thanks! Gerry
40 to 45 mpg is pretty normal with a Gen-1, in my experience. if it is really cold like you are saying, that could easily account for the 5 mpg difference. However, if that is the original battery you can be sure there is not much life left in it, so that could also be contributing.
I set up the scan gauge to show the high and low block voltage. Watched it driving to work. Biggest difference I saw was .5V. Both high and low don't update at the same time, one was just after the other. Most of the time they were .3V or closer together. I did see both voltages the same a few times. When I got to work and parked it, sitting with the car ready and the engine off it was only .2V difference. On the way home stopped at the store and ready with the engine off it was .3V difference. Do have to say I'm impressed, 38 modules, over 10 years old, still that close together in voltage. As for mileage, will see as the weather warms up! Thanks! Gerry
Seems like it is pretty normal, for a battery with that much age and wear. Just so you know, if that difference gets to around 1V, that usually means you have one module that is weaker than the other 37, to the point that one of the cells inside the weak module is close to 0V. If you see that, it would be possible to do a preventative reconditioning so that you don't have to replace the weak modules or the pack.
I've never had a Gen 1, but Toyota Prius: Consumer Reports might help. What tires are on the Prius now? About how long are your trips in miles and minutes? What are the outside temps like during your trips?
I still have my '02 Prius and in the temps and speed you're mentioning, 40mpg is what I've been getting during our cold weather months. Mileage will improve considerably with temps in the 50s and again better with temps in the 70s. Consider an engine block heater and/or some form of grill blocking to improve mileage at those lower temps. Also, I get my 30-35mph stealth mode most after driving for 15 minutes or so (I don't have the block heater), or coming off of the faster speeds and then coasting at the lower speeds. Only expect a couple of miles at a time on battery only, but also expect display mpg ratings of 60-100 mph in the 5 minute increment bars. I would wait until the outside temps are in the 50s and after the 1st 10-15 mins before expecting mileage improvement. BTW, my '04 Prius gets approx. the same mileage, and short trips/idling REALLY kill the avg mpg especially in colder temps you mention. The idling will stop a lot sooner with higher outside temps.
The previous owner put on 185/65 14 Cooper CS4 touring tire. I've had them at 40psi. The temps are going up, I'm up to 42 on this tank after a little over 200 miles. My drive to work is mostly interstate, 15 miles each way. I'm finding that I do better when I cut some of the interstate off and go through town! Thanks! Gerry
A block heater is on my list before next winter. I had a Ford Aspire and worked on Hypermiling it and could get in the low 40's with it in the summer time. I'm slowly learning on the Prius, I do have a few spots I can keep it in steath mode, just isn't easy! Thanks! Gerry
Filled the tank yesterday, drove it to work, took another trip today, mostly interstate. Temps in the 60's. I have 75 miles on the tank, average 47mpg. Thats closer to what I was expecting! Thanks again for all the replies! Gerry
