grid charger/balancer

[Mike Dabrowski 2000]

The problem with "other vehicles" is that I don't have service information to develop the best connection hardware to interface with the pack fans and temp detectors. That will come later.
The present chassis layout will allow 1-4 of the 48V base supplies, so 360V will be out of range, but the US gen 2 Prius should charge correctly with the 4-48V supplies and the two CC supplies.
Guess you will need to make a grid charger extender module with 2 more of the 48V supplies for your first gen packs.

[Cobb]

I echo Jim's comment.

If you get the basic charger design, Ill help with connecting it to the i2.

Originally Posted by Mike Dabrowski 2000

Thanks for the kind words.
I am back on the grid charger project, and hope to be able to capture the parts and labor cost soon, so I can set some prices.
I am still looking for the best bulkhead connector to make the 6 connections that I require for the system.

[Mike Dabrowski 2000]

I will need help determining the best interface from owners of the I2, and the civics, as well as the second gen Prius, once the system is ready.

I settled on the Amp Tyco CPC (Circular Plastic Connectors).
206705-1 Tyco Electronics / AMP Standard Circular Connectors
I will use the size 13- 9 pin standard bulkhead, with mating plug terminated with a strain relief.
The bulkhead connector can have a protective cover, to cover the bulkhead connector when not in use.
Ordered enough for 50 chargers.

[nursemike]

Originally Posted by Hybrid-Battery-Repair

This sounds more like a downward recal to me. It sounds more like the BCM detecting that the indicated 40% is actually closer to 0% and then recalibrating the bottom of the SOC gauge. Is it repeatable? Can you do it twice in rapid succession, or does it not do it again for a few days?

It's possible that you force-discharging your pack is triggering these due to different cell performance at different pack temperatures. The way to tell would be to reset your IMA and do a battery relearn. Then see if the car acts any differently (the battery charge seems to last longer before depletion, etc).

By "resetting" the IMA do you mean throwing the master breaker switch on the front of the IMA pack?

[nursemike]

Originally Posted by Mike Dabrowski 2000

I will need help determining the best interface from owners of the I2, and the civics, as well as the second gen Prius, once the system is ready.

I settled on the Amp Tyco CPC (Circular Plastic Connectors).
206705-1 Tyco Electronics / AMP Standard Circular Connectors
I will use the size 13- 9 pin standard bulkhead, with mating plug terminated with a strain relief.
The bulkhead connector can have a protective cover, to cover the bulkhead connector when not in use.
Ordered enough for 50 chargers.

Would something like this:

1N000-RMX-030

work?

Found the part # at Bernardi parts

Find Honda Parts and Honda Accessories by Car Model - Bernardi Honda Parts and Accessories

A new IMA harness is $$, perhaps salvage parts are available?

[satchel]

Originally Posted by nursemike

work?

$135 versus $2?? I'd say no.

The relearn is accomplished by disconnecting the 12V battery negative, not flipping the IMA shutoff switch.

[nursemike]

I more expected that the connectors might be of use from a salvaged IMA battery, etc. A new one clearly was way too much money, especially since almost all of it would be scrapped. I'm just thinking about simple, (relatively) safe connection options.

I d/c'd the 12volt battery for a couple of hours a couple of weeks ago, will no improvement in IMA performance. Oh well...

[Mike Dabrowski 2000]

The CPC connectors will do the job nicely. The 9 conductors will allow PTC monitoring,dual charge rates, precision voltage measurements, fan control. The small PC board with + terminal connector, fuse,precision resistor, two diodes, will be very safe, so I am happy with everything about that connector, except for the $20 price tag. I will include the screw on cap for the connector for whe n it is not being used.

I had to make up some fan connector shells, order more tyco receptacles, and make more of the pins, so the fan connection will be a plug in on the insight version.

Need to get a couple of other projects off the bench before I tackle the controller/LCD display.

[uhtrinity]

I want to add some more information related to the chargers output voltage. This will apply to the 'dumb' chargers like the Meanwell based units.

So far I have set up two cars with dual battery packs and dual chargers. My car charges fine and has a reasonably safe charging profile. However my friends Insight has had some charging issues, mainly battery over heating.

My charger is set to 170.5 volts (post diode at the battery terminal) and has a profile of bringing the battery from 140 volts to 169.5 volts in roughly 8 - 10 hours. This is with a 130 - 140 watt draw at the outlet. When out of sunlight it will then drop to 30 - 50 watts and maintain this charge level until the battery pack heats up and the pack voltage level starts to drop. This allows a ~14 - 18 hour charge on a normal summer evening and morning. Charging in full sunlight is not recommended.

My friends charger was set to 171 volts. This minor difference made it so his charger never dropped charge level and resulted in battery temps of up to 60C or 140F and it would happen often unless unplugged within 8 - 10 hours. Even sooner if the batteries hadn't been drained enough. We have since dropped his charger voltage to 170 volts and he now sees the dip to 30 - 50 watts along with normal ambient battery temps.

Since the Meanwell Chargers will supply full current (350ma per unit) to within 0.5 volts of the battery pack I recommend caution if leaving the charger unattended. The safest course of action is to lower the voltage (post isolating diode) to 170 - 170.5 volts.


edit: I want to add that since I started using this method my batteries have been at 168 - 170 volts every morning and get a 'key on for 2 minute positive recal" 100% of the time. Balancing should still be taking place on those morning when the charger is 'accidentally' left on until midday.

[Mike Dabrowski 2000]

Interesting Mark, If I remember correctly your chargers are higher current than the 350ma and 1A chargers I will be making?

I have had 350ma on a pack for over 2 days with 12V fan running, with only a 3-4 degree temp rise above ambient.
The pack was in thermal zone at over 170V for the last half day of that test.

For everyday charging,I agree that having the charger run out of volts near the full point should be better than balancing each day.
To assure full balancing, all cells must be full and converting the full 350ma into heat, so I will set the max V to several volts over the max that can be reached just to guarantee that all cells get filled.
Since this is easily adjustable, maybe we raise the V to 175 for the occasional balancing, and leave it at 169-170 the rest of the time.
Of course this max V is a temperature dependent variable, so maybe the pack temp should determine this max V?
I am just getting into the final smart grid charger control system design so lets figure out what features we want to include. The Microcontroller will be reflashable and socketed like MIMA, so we can keep improving the control strategy as we learn more.
I plan on being able to turn off the 1A and also the 350ma charge by computer control, so the hardware max V can be set to 175V, and the charger will simply shut off when a programmable target voltage is reached, the charger times out, the MAX AH is reached, or the PTC strip indicates a hot cell.