Ok I got an 01 prius about a month ago, love it, in great shape. has 151000 miles on it currently. I hardly ever see the battery meter move. car is showing 45 mpg, first fillup was 53.76 mpg, second fillup was 41.85 mpg but it was run hard and had a/c on. I had taken the hv battery and cleaned off all corrosion, and applied battery terminal protector on bussbars, cables, battery terminals, and put it back together. My voltages ranged from towards the outside of the pack 7.68v, and towards the inside 7.57v. The voltage at the battery ( the 2 terminals where the back seat is) when the engine shut off was 289v the peak voltage when the engine was on was 298v . After cleaning the battery, the voltage when the engine shut off was 313 with a peak of 333v. So my question is I read about battery maintenance/ equalization via PDF i uploaded below. But I dont have the equipment to charge this battery. I can get it discharged like they tell on page 3 of the PDF but how can I keep the engine running to equalize like they tell you to do on pages 6-7. I do have a super brain 977 and can charge 2 batteries at once and discharge one at a time. I want to keep my battery healthy and believe it is still in great operating condition. thank you for your input and advice. Scott
It appears that your battery is working great, and I think you should leave it alone now, just drive the car.
Your Prius is designed to keep the HV battery well cared for. As long as your car is working good and getting good mpgs (which it is), your HSD system will keep the battery charged at the correct levels and protect it. I would do just like Patrick says. There's really no reason to read into anything unless you're getting a DTC. Sometimes the best intentions can cause the most problems.
The best way to keep the battery in top shape is to keep it a cool as practical: park in shady areas during summer - you don't want the trunk and cabin pre-heating the traction battery. avoid 'heat pumping' - charging the battery is exothermic, generates heat, so things like (1) forced charging (holding the brake with holding down the accelerator), or (2) a hot of high-speeds, 60+ mph on the ascent, steep 8% grade, +500 ft. hills, should be avoided because on the climb it can discharge the traction battery. If you see the traction battery go down while ascending a hill, slow down on the upgrade. I love to follow heavy trucks in a truck climbing lane. On the descent, control your speed using "B" to minimize the risk of overcharging and 'heat pumping' the traction battery. BTW, I'm talking 500 ft or higher hills. If you can get some Prius instrumentation, the traction battery has four thermostat readings. One is the ambient air inlet and the other three are the ones to watch for overheating. FYI, try not to spray a hard force, water jet in the side, air-inlet. Enjoy! Bob Wilson
Thank you guys for your input. It is appreciated. I am one that likes to keep up on maintenance. And that Battery is no exception, that's why I want you guys opinion first
It depends upon what you goals: driving and field diagnosis ($150) - ScanGauge II with up to 30 XGAUGES defined to read out engine, hybrid, battery codes and subcodes (15). I would also add lowest and highest battery pair voltages and numbers (4); MG1 and MG2 temperature (2); minimum/maximum battery temperature (2) and; battery temperatures (4). While driving, I would use the ICE rpm, gallons/hr, and ICE temperature because these are useful during warm-up and driving. I would also check minimum voltage module ID which should change from time-to-time in a healthy battery. Once the car is warmed up, I would switch to ICE rpm, MG1 temp, MG2 temp, and minimum voltage, battery module pair. However, you could switch them up as your interest in different subsystems increases. diagnosis, repair, and engineering studies ($500) - AutoEnginuity with your PC, order the Toyota option. The PC makes it too bulky to use as a driving instrument (although the smartphone option might work.) The big thing is you can do battery, transmission and engine studies to look for subtle trends or detailed faults. The field of OBD scanners continues to change and there are others. However, it hasn't been clear that they are as affordable and flexible. These I have tested and own along with the old Graham miniscanner. Bob Wilson
