What is a good way to charge a traction battery out of the vehicle?

A good idea regarding purchase of a used high voltage DC power supply. I would use the 0.5A constant current concept, with the voltage set to 235V.

Toyota recommends charging the traction battery at two-month intervals by making the vehicle READY for 30 minutes, when in storage.

 

I tried using a Electrophoresis power supply. They do not work as battery chargers. I am not an EE so the most technical explanation I can give is that the Electrophoresis power supply does not expect or accept 220V pushing back at it. The easiest way to charge the pack is to just put it in your car.

You most likely will never need another battery for this car. However Prius do tend to multiply in families so you might find a use for the spare battery. The one battery fault that can not be repaired is self discharge. It is also a very easy test to perform. Just let the spare battery sit. Any module that can hold 7 volts or better indefinitely is good. I have modules that sat for four years and held above seven volts. Any module that falls below 7 volts is junk not worth trying to revive. There is a little gray area between 6.5 and 7 volts.

If you really want to build an Ebay salvage parts 400 mA charger I can tell you how, but I feel that if you have to ask then you probably should not build one. And eventually someone who really should not build one will read the directions.

Brad

 

don't forget to check one them while charging, they can swell and expand making them worthless if over charged..Id just sell the battery if you don't need it..it will bring more than you paid on ebay

 

Ditto selling on Craiglist or eBay if charging turns out to be a pain. That's what I did recently--bought a salvaged battery and sold my old "core" after it sat on the bench for nearly a year as I looked for charging options and couldn't find one worthwhile to pursue (and I am an EE). You may have better luck than I, or have different criteria. I was not sorry to see it go and the cash was nice.

 

I would love to have a working Electrophoresis power supply. I bought a VWR 570 the same model you are using. It will power on and produce a nice steady current or voltage through a resistor. When I try to connect it to just one module the DC start button will not engage in either constant volts or amps. I have not tried it on a whole pack. The adjustment knob on my supply spins ten full revolutions. How many revolutions did it take to set the voltage at 214? Am I doing something wrong?

Thanks, Brad

 

If it doesn’t turn on because there is already voltage at the output (battery voltage) you just need one diode to fix it.

 

The diode did the trick! It helps to hold the start button for a few seconds while the power supply thinks things over. The power supply seems much happier and more cooperative at full pack voltage than just one module. I started charging a pack with the constant voltage setting close to 235 volts. The power supply will put out up to 2.5 amps and growls a bit at over two amps. As the battery voltage rose (the charger stayed pegged at 235 volts) the amps tapered down. When the power hit 300 mA I switched over to constant current to let the pack simmer for a few hours. Voltage peaked at 236 and then fell to 231. That works out to a delta peak of 30 mV per cell. In a total of eight hours I took a pack from about 60% SOC to full with a quick charge at the start and finishing with an easy 300 mA slow charge. Tomorrow this pack will be ready for individual discharges.

Thanks for the help,
Brad

 

Strawbrad, i recently got an EC570 and i soldered a diode (not sure of the rating but the guy i got it from says its over 400A) in the positive end of the cable that leads to the battery from the EC570 to prevent reverse current going into the EC. When the system is turned on without connection to the battery,it does not engage for either V or A. However, with a voltmeter connected to the ends of the cable, it engages. Subsequently, when it's connected to the battery using the cable with the diode in the positive side, it does not engage. Do i have to use a diode on both cables - positive and negative?

I checked the opposite ends of the cable while its connected to the battery terminals and there was no voltage coming from the battery so i really don't know why the EC will not engage. What do you think that i am missing?

I tried using the meter also just as in the picture to create some resistance but it still did not engage.\

Strawbrad, can you possible show me what your connection looks like?

 

Everything has been shrink wrapped inside the jumper cable. Not much to see now. The diode I used was rated for 400 volts and 5 amps. Is it possible you installed the diode backwards? The orange safety plug has a 125 amp fuse inside. I replaced it with a 2.5 amp fuse for bench testing work. Be careful testing high voltage .

To start the power supply set to constant current, turn the adjustment knob all the way to the left and then clockwise two revolutions, then hold the start button for up to ten seconds. It should start up at about 500 mA.

Brad

 

I would limit charging current to C/80 (about 75 ma). This is a rate that should allow oxygen reabsorption and you won't need a fan.

 

I don't see anything that i have done differently except for this. Do you mean when you are charging the battery using the EC, you use a plug which has its fuse replaced from a 125amp to a 2.5amp?

I try to pay attention and wear my glove while working on my battery, though i need to get better rated gloves ...working in it.

While holding on the start button on constant V for about 2 seconds, i hear this ticking sound as if the EC is rejecting the setup based on some parameters, which makes me let the button go. I have never tried holding it for more than 3 seconds while it ticks.

Did you have to use a meter for added resistance?

 

Yes, It's just another layer of protection. The fuse does nothing to prevent shock hazards. It can prevent melted jumpers and such if things go very wrong.

It makes some noise just before it starts up. It makes a different noise and then goes silent if it shuts down. Two or three seconds is not enough time for it to start up.

No, I did not have to use a meter.

Be Careful !

Brad

 

Thanks Strawbrad, i will.