Guys, I recently accuired a 2004 Toyota Prius with 200k on the clock. I have a few questions that hopefully can be answered to aid this project. #1. The current ICE threw a rod through the block. (Can ANY ICE from 2004-2009 drop right in? I mean no new harnesses, new computers, bs like that. What years will drop in.) #2 It is possible the HV battery is bad. I plan on replacing individual cells after testing. Is it possible to charge one cell at a time? 7.2v. #3 I believe I maybe be in a bad situation with a HV discharged and sitting for 2-3 months which will not allow the ICE to start. I have yet to find a charging solution other than the ICE when its running. So once the ICE has been replaced how do I start the ICE without a brand new charged HV battery?
There still can be enough charge left after 2-3 months to crank the engine. Even 6 months might be OK.
You cannot charge one cell at a time, only 6 cells in one module (7.2 volts) can be charged since individual cell connections are not available on the outside of the module. The modules can be "and should be" charged and balanced using a Suppermate DC6 charger or similar, but this is a long winded process "expect 28 days with 1 charger" The engine from any gen2 Prius of any year 2004/2009 will drop strait in. There has been one report on here of a battery starting a car after being stood over 2 years, six months is not a problem. John (Britprius) What is your level of electrical skills. John (Britprius)
John, I miss spoke when I said one cell, I meant one module. I will take a look into that charger. The time the car has sat may not be the problem, rather the fact she thought the battery was going bad because the car became very sluggish before the ICE threw the rod. Hopefully she was just experiencing reduced ICE power and the batteries are fine. Thanks for the help.
John, If this was directed towards me.. John (Britprius) What is your level of electrical skills. John (Britprius) I am very good with electical circuits and computer components. I have some good tools (oscilloscope Fluke 190, few ac/dc power supplies and surplus of electronic components). Looking forward to the challenge!
With a reasonable level of electrical skills a basic charger can be built for very little outlay to charge the battery as one unit "if HV battery is to low to start the car, but is otherwise believed to be sound". If you find you need to do this I can talk you through it. John (Britprius)
John, Can you elaborate on the charging of the HV battery? I was going to buy one of these to speed up process. Thunder T6 Multi-LiPo Battery Charger (4X 6-Cell) Professional Balance Charger/DisCharger w/ LCD Display
John was talking about a 200+ volt charger to charge the whole HV battery at once. You not only want to charge each module (the unit you reference can do 4 modules at a time), you want to balance them. You need to clamp each module as pressure can build up during the process and cause the sides to bulge out. Don't clamp them in a group unless you clamp a group of eight and work on every other one to avoid over heating the modules being charged. Put each module through 3 discharge/charge cycles, the capacity will increase on each pass with diminishing gains. This takes over a day to complete the set of 4 modules due to the power limit (5 watts) during the discharge cycle. Make certain to set reasonable charging/discharging levels (the defaults are not bad for NiMh in my unit, a similar but single module unit, but I limit charging to 7500 mah for safety). After letting each module rest for a day or so you can discharge those that have a higher voltage a bit to get them all to the same level of charge before reassembling your HV battery. It is a good idea to use a large 12v marine battery and a battery charger (or a large UPS) as the power source as a loss of power during the process looses the stored data about your modules. JeffD
Jeff, Let me explain the situation a little better since there is some backround. I bought the prius with a blown ICE. The day I got the car the HV battery was showing a single red bar in the charge status. I pushed the power button twice and the dam thing started up the ICE. Exactly 30 days later, charge status shows an empty battery outline and now I cant start the new ICE to charge. I get a Red triangle and No Ready light. So what is my best option to just give it enough power to crank the ICE without spending a month charging and balancing batteries. At this point I have no power at the battery leads at the inverter lugs. I assume thats due to the lack of ready light on dash. This is a far stretch, could I not just attach a 12 volt optima in series with the HV to get the Voltage above the "threshold" allowing it to start one time? This is of course assuming the low voltage is holding out the contactor in the battery pack. Thanks
John is probably giving you instructions on how to put a charge into your battery to get you going. Given the work that you have already done on your Prius, I would consider doing a rebalancing of all 28 modules to insure that you won't have to go back into it in a few months. If you can rebalance 4 at a time, the task will take a little over a week in elapsed time. JeffD
