grid charger/balancer

[Mr. Mik]

Originally Posted by Hybrid-Battery-Repair

I'm not sure you realize how bad some of these packs are. One cell? Try a dozen scattered through a typical P1447 pack.

I'm talking from the perspective of an owner-operator with a relatively good working battery that then develops a fault. The main function of a grid-EQ charger is to keep a good battery healthy - and to a lesser degree, salvage or prop up borderline batteries.

I'm working on NHW10 Prius cars (same cells but double as many and different BMS) which seem to treat the battery more gently than the Insight, but my battery sample size is too small to be certain about this. I have found one battery with around 1/3rd poor sticks, but the other 5 batteries seem to consist of 99% good cells (i.e. between 1 and 3 poor cells in the 240 cell pack).

[dgraham0731]

I've been reading and searching all over for info about the grid charger/rebalancer. i found this website that sells a 180v DC .2 amp box. I'm wondering if anyone thinks this could be used as a charger for the ima pack? i know nothing about the packs, so any info would be great. Thanks.


Acopian Power Supply Model U180Y20

[retepsnikrep]

That is unregulated so will try to deliver a high current when first connected to a discharged battery which will probably blow the fuse very quickly. If you added a regulator to limit current to ~200ma you might get away with it. However it's dumb with no safety features, much better to get Mike's charge IMHO.

[satchel]

Originally Posted by Hybrid-Battery-Repair

Sorry, you can't have a blue pack. Production are (what else?) green.

Oh dad gummit! I thought they went good with the Monte Carlo.

Have a pic of the green? I like green too.

[Mike Dabrowski 2000]

dgraham0731,
yes it can work, but you would need a big power resistor to limit the worse case current to less than the .2A the thing is rated for.
If the pack was at 140V, and the power supply at 180V, you will need a 10 Watt 200 ohm resistor in series, to limit the current to the .2A. The resistor will get hot, and as the battery charged, the current would drop, lengthening the charge time substantially.
This setup180V with 200 ohm resistor, with an empty pack, it could take 2-4 days to charge and balance once.

The major advantage of the Constant Current LPC-20-350, is that it will put out 350ma till the battery is charged, and will adjust its output voltage automatically as the pack charges and raises in voltage.
I looked at a lot of other ways to do this before settling on the approach I used.
This approach gives good reliability, as all supplies are opperating well within their power band,is scaleable and is reasonable in cost.
Any isolated 48V power supply with the ability to output 400MA and any CC led supply with 350ma and wide CC voltage range will work.
No safeties means just that.
My charger will take the better safe than sorry position,and will watch overall pack temperature gain, PTC (individual cell getting hot) fault detection.
Hope this helps people better understand how this works.
Basic 350ma charger
http://99mpg.com/Data/resources/down...balancer_2.pdf

[dgraham0731]

Mike,

Thanks for the reply. I got the 2001 Insight about a month ago and have just started reading this forum.

Are you still taking deposits for the overnight charger?

If so, can I pay you by paypal and e-mail you a scanned copy of the liability waiver or would a check and hard copy be better?

Thank You,

Dave

[Mike Dabrowski 2000]

I have 53 people signed up, and will be building 100 chargers, so I will be accepting deposits until the backorders are shipped, then I will just sell them as we will have captured the cost and will have firm pricing.
I need the signed hard copy of the forms, as I will include a copy of the signed document in a pouch under the charger.
Update:
I again told the backyard inventor people that I was not interested, so I can fully concentrate on the chargers.

[3-Wheeler]

The BCM is now powered up during grid charging, and seems to work great.

The red/black wires are used to supply 12 volt DC power to the BCM when the car is off.



And here is a DC connector mounted on the outside of the IPU.



And here is the second diode that Peter recommended. After adding the diode, the current stabilizes at 0.38 amps and stays there unlike the previous action reported with only one diode present.



One other observation after using the system for several days...

When first turning on the ignition key in the morning, the SOC registers the old level for a few seconds, then moves up to the new level slowly over the span of 10 seconds or so.

Jim.

[Eli]

Ahhh....

0.38A seems a little more like it.

[thedhgroup]

I'm building my own 350ma charger and will use it on my recently acquired insight as soon as the constant current supply arrives (i already have the constant voltage ones). My question though is with a spare pack that came with the vehicle. I measured the voltage at the points where it is suggested the charger be attached. I read 0v and to test the meter I measured 12v across a car battery so I know my meter works. Chances are the spare pack is toast since it has sat for over 2 years.

So if I try to charge this thing, shall I just start with the CC supply and when no current flows put a CV supply in series until I get up to 3 CV supplies and 1CC supply in series??

My thinking is that if the CC supply regulates its output by adjusting voltage it can't adjust itself low enough for a pack starting at zero if I put them all in series from the beginning. The CV supplies will be in a constant state of error protection.

Can I start the process by hooking a good old fashioned 12v battery charger to wake this thing up? Charging at 350ma is gonna take weeks.