grid charger/balancer

[Mike Dabrowski 2000]

Happy New Year!
The power supplies showed up yesterday, so I will be building up a test system soon.
I got a couple of extra 48V supplies with the idea of making the supply also charge Prius packs, as part of the Prius based booster system I am designing.

[TRI]

Happy New Year!

I like the idea of having the fan running. Does it run all the time while charging or is it controlled by a thermal resistor? I don't know how the IMA system controls it or by how many thermal resistors at which locations. I would feel saver in the long-run if the fan is only running when it has to. For those wanting to charge it nightly it could result in an much earlier fan wear out (bearing). Or am I completely wrong?

[Mike Dabrowski 2000]

The fan will run during the charge, but at reduced speed, so the wear will be minimal.

[Hybrid-Battery-Repair]

Originally Posted by Mike Dabrowski 2000

I have been experimenting with a two step charging system that would allow a full charge on an empty pack in 5-7 hours while still allowing a 350ma finishing charge.

Granted I'm not the average user, but couldn't you make one that charges significantly faster? For example, 6 amps primary charge would draw about 1100 watts and take about an hour to get to your secondary step.

I currently charge batteries before they ship by using ten chargers at their max of 6 amps for 12 cells each (and their power supplies draw a max of 110 watts each). It takes about an hour from empty with an average pack to reach delta V and then I have them set to apply a 350 Mah trickle charge for one hour after that to make up for any variations between the chargers.

With the fan on, the cells stay cool.

In fact, with the fan running at 9V or more they will stay cool if discharged at 30 amps.

Two hours - I can have it in a crate in time to make my UPS pickup.
Five-Seven hours - I can't.





You might find this interesting:

I'm getting one of these made for me right now.



It is a tester that tests charge and discharge performance and internal resistance at up to 50A for a twelve cell stick pair (Gen II batteries).

Here are two shots of how these commercial units are made:

http://hybrid-battery-repair.com/bt2.jpg

http://hybrid-battery-repair.com/bt3.jpg

[retepsnikrep]

Bloody hell Ron that looks expensive.

So it is a charger and discharger for upto twelve cells sticks.

How many channels does it have? Will you be using it on MK1 packs?

Do you have any technical information on it?

[RobertSmalls]

Another advantage of a thermally controlled fan: It can allow you to start with a warm battery. My battery delivers terrible performance (max. charge rate and capacity) when it's very cold. With a 6.5A charger, I could turn on the charger when I wake up, and have a hot, full battery on the morning commute. Anything slower than that, and a timer could be used for a similar effect.

[Hybrid-Battery-Repair]

Originally Posted by retepsnikrep

Bloody hell Ron that looks expensive.

That one is an 8 channel unit and costs $15,000 plus freight from Asia. It consumes up to 8,000 watts (and can dissipate 8,000 as well). I can't afford to buy it or upgrade my electrical service for it, so I'm getting a single channel model.

Originally Posted by retepsnikrep

So it is a charger and discharger for upto twelve cells sticks.

How many channels does it have? Will you be using it on MK1 packs?

Do you have any technical information on it?

It is up to 20 volts at up to 50 amps. My single channel unit will be in a 4U case and will charge-discharge-IR test a good quality Gen I stick in about 30 minutes with a cooldown period in between or 15 minutes without cooldown. (A GenII stick would take 45 or 30 minutes.) My current discharge-only testing takes about 15 minutes per stick without charge testing. Also, the IR testing should do away with my one week self-discharge testing and shave a week or more off a repair.

Better tools make a better quality repair. Now I have to see if I need to test at multiple amperages. I know that I can find defects at 30 and 50 amps that I can't find at 10, but the inverse may also be true.

But, I still need to recondition prior to testing, and (Mike are you listening?) I still need to charge up the pack just prior to shipping.

[Mike Dabrowski 2000]

The typical ball bearing fan like the one in our battery packs is typically rated for 60,000-100,000 hours. That's 7-10 years of running 24-7 at full power. Fan life is not an issue.

Ron,
Contact me if you want to discuss a custom charger, the concept of using multiple supplies can be expanded to provide just about any combination of constant current and high rate charging.

This new design is to produce a low priced charger that can charge a depleted pack to full overnight, without any danger of overcharging.

[TRI]

I'm watching out for a secure male/female connector set, 250V, 4-pole or more, with a cap on it, attachable only one way. 4-pole because I want to carry the 170V and 12V in the same connector. The female will be put on the charger-side, the male side on the battery-side where I want to have a cap on it as I don't like the idea of having battery voltage lying around open in the trunk. Does anyone know of one. I've been searching for quite long in the electronic parts catalog but couldn't find the right thing.
Or would you better go with two separate plugs?

[mrbigh]

Originally Posted by TRI

I'm watching out for a secure male/female connector set, 250V, 4-pole or more, with a cap on it, attachable only one way. 4-pole because I want to carry the 170V and 12V in the same connector. The female will be put on the charger-side, the male side on the battery-side where I want to have a cap on it as I don't like the idea of having battery voltage lying around open in the trunk. Does anyone know of one. I've been searching for quite long in the electronic parts catalog but couldn't find the right thing.
Or would you better go with two separate plugs?

Go for two Anderson connectors of diffferent colors, simple a reliable.