The Do's and Don'ts of Grid Charging...

[bigjim56]

Ok, I spent all day gutting an old PC case and installing all of the necessary parts & wiring for my first grid charger. Thanks to Mike Drabowski for the schematic and to Ablinkin for the Jameco Electronics parts link. All that's left to do is run by Radio Shack for the fuse links, then O'Reilley for the Dorman part #85412 for the hook up directly to the Hybrid battery.

Now comes my concern...ya' see back in my old Maintenance days, when it came to my electrical work, well, my nickname was Sparky......I did a lot of other things very well, but electrical @#$%^&*!!!......WTF!

I'm gettin' better though, I looked and studied the schematic for days before the parts arrived. I think it's all correct, I did continuity tests on the grounds, terminal to terminal etc.

So, from all of the reading of the threads from here I've written down some pointers already...

1) Make sure you flip the breaker "off", "then it's really a question of piggyback spade connector (Dorman) and a ring terminal."

2) Use the battery fan (RS-25-12 of grid charger) to rid battery of built up heat from the topped off cells.

3) Expect the SOC to do a recal when first using car after a grid charge...due to the voltage being different than when it was last shut off.

Now, for everyone else's feedback please. If I missed anything, please mention it, so we (I) can have a teachable guide to go by. What sort of voltages should I be looking for and where should the measurements be taken. I've got an old Micronta from my Maint. days (no, it did'nt melt...I've replaced a few fuses though...).

I did a search of this title and could'nt find much, it kept guiding me back to the grid charger construction threads, so I know this will help others as well.

Thanks,

bigjim56

[Eli]

Sounds good overall.

Depending on your BCM revision and some other factors, the car may or may not do a positive recal after grid charging. Some BCMs will do a positive recal after 2 minutes of key-on at 168V, some require much higher of 174V and some may not do it at all.

Measure voltage at the same places that you hook the grid charger. Measure the voltage of the grid charger after the diode(s).

[Ablinkin]

The voltages on my pack were running about 156-160 before I used the grid charger. The highest peak voltage I saw after 24 hours of charging was 175 and varied between 173-175 on the later charges. Mine hasn't gone through any more recals after the initial grid charge and has been great since.

One thing that really should be stressed is to fuse both negative and positive leads entering the metal case near their connection points. I know I've mentioned it before but I almost had a vehicle burn up due to the positive lead passing through the firewall unprotected. Company truck and poor installation.

[bigjim56]

Thanks guys for the inputs, I will take measurements before, during and after the initial charging, which I plan to do about a 16 hour charge on the first run, wait a week, then hit it again. I'll keep a log to see how the charge of pack is doing...I would think it would be increasing, seeing as though the weaker cells are being brought up to the level of the stronger ones through the grid charging. Once a high enough initial pack voltage is reached, I can back off the grid charging to once every month or two.

Not quite through my FIRST FULL TANK and I'm at 440 miles w/about 1/3 of a tank left. I love this car! I stop the filling at an even 10.0 gallons, so it's easy to estimate the mpg's. 44 mpg so far,...hoping to reach 60!

Now off to Radio Shack and O'Reilly's...

Sparky......over and out...

bigjim56

[Eli]

The Insight's tank is 10.6 gallons. Just fill it all the way up, then record how much you put in next time and calculate your MPG. I keep tabs on both FCD MPG and actual MPG.

[bigjim56]

Went to O'Reilly's...then Radio Shack...then a different O'Reilly's...then on to Lowe's and was unable to find the 1 Watt white LED 350ma fuse or a 200VDC 1A.

Are the ac/dc fuses interchangeable?...I got some 1A dc fuses for the fast blow. I've did a quick search on google/ebay/etc. The only link that was helpful was the 99mpg.com/projectcars/mimapackwhack/ link that showed Mike making a ohm resister type bypass attached to a white block...he said it was due to having blown a few of the 1A fuses due to initial hook up voltage surge. Is that what I have to do? Buy a resistor and cook up my own, or are there some of these on the shelf somewhere's?

I would trust the shelf unit personally...

10.6 gallon tank...thanks Eli...I'm now to 499.6 miles, w/5 bars of fuel left......it's looking like the trip mpg calc. is pretty accurate...it's reading 60.6 mpg and slowly increasing.

Thanks,

bigjim56

[Eli]

AC fuses are NOT interchangeable with DC fuses. High voltage DC fuses are special and able to squelch a DC arc. This isn't necessary with AC since it cycles to 0V at a certain frequency.

You're not going to be able to find anything like that at stores like Radio Shack or Lowes. You'll have to order them online.

The link you posted is a replacement for the 1W LED, as he was blowing the LEDs out with the initial current inrush. Replace the 1W LED with this schematic, which should be available at Radioshack:



The FCD overall is very accurate.

[bigjim56]

Thanks for the reply Eli, it's a big help. I'll get the necessary parts from Radio Shack this week and make my own 1W LED fuse link, the 200 VDC 1A I'll google search and order on line.

I guess I was suspect of the FCD because I lumped it with the SOC which is inherrantly innacurate because of the 20% top/bottom ignorance of battery's actual charge, plus the dash lights are commonly referred to as "idiot lights".

Ablinkin - I understand the need for fusing by the metal casing wireways - "chaffing" has brought down airliners and fighter jets, I don't want it burning down my house...

Thanks,

bigjim56

[bigjim56]

Ok, I need help here. I've been working soldering the 1W led 350ma(s) together and installing the in line fuses, I thought I'd give ity a try, so after rechecking all of the hook ups/grounds/neutrals/etc. I plugged it in...nothing.

Replaced fuse, plugged in again...another blown fuse...

I keep blowing the 1A fast blow fuse that comes off the ac line voltage in, I replaced it, plugged in again ...same thing. Glad I bought a lot of those fuses.

Seems to me as though a 1A fuse is an awfully low cap for incoming voltage to a recharging grid, but I chose not to bypass it to prevent further damage downline. I'm giving up for the night, or I'm gonna have diodes and fuses dancing in my dreams.

The grid charger is on a bench, nothing else plugged into/from it. Is this ok? I was gonna check the outgoing voltage - 350ma to the pack, and the 12V outlet to the battery fan, but with the fuse blowing I can't check *hit!

Appreciate any help...

bigjim56

[ghammerly]

I built this charger too and and had the same problem when plugin the power chord to 110v. I think the transformers suck up a bit more than 1A when powering up.
I switched to a 5A fast blow for the live 110v input and that worked. Maybe a 2A fuse would be enough but didn't try.
No problems with the 1A DC fuse.
As far as I know fuses don't care what kind of current they get. (ac/dc)