How is grid charging different than driving?

[Cobb]

I think the confusion lies in the use of a charger from the grid.

Is it to fully charge the pack vs balance it? I cant see any harm in doing a full charge and then stopping. Balancing does generate heat and requires cooling or it could swell, vent, loose electrolyte, catch fire, fill car with smoke, etc, etc, etc.

I charge my pack daily to almost 100% with my phev kit. I balance it with a gird charger every 90 days or so.

Sent from my Autoguide iPod touch app

[planete]

Originally Posted by thedhgroup

What exactly "is not good"? Is it the possible heat? Do the cells swell and or let off gas or something or is it a chemical reaction thing? If it is a heat thing, what would happen if we used 100ma instead of 350ma? I know it would take forever but...

Here is my plan. Currently I charge at 750ma (twice a day when over 40 degrees F.) but I have a timer that shuts it off after 3 hours. Seems to trigger a positive recal quite nicely. Sometimes 3 hours is not quick enough for me. Sometimes I only stop for an hour. I'd like to build a 2amp charger that runs up to 1.5 hours, replace the stock fan with something that actually moves air and then a 100ma charger would run indefinitely if bat temps are at or below 90 degrees. (anybody else wanting to do the same thing should take heed from the experts, I'm not one, I generally just push buttons until I get something to work)

Heck, I brought my pack back from near dead so I don't care if I fry it. I have a new one waiting to take its place. Today I was feeling frisky so I did lots of full assist runs, killed my MPG but the pack held up down to 3 bars without a neg recal. I've been charging twice a day for 6 months if over 40 degrees. Under 40 degrees I don't get a positive recal so I gave up trying.

What exactly did you do to bring your car back from near dead? Also, how long has your car been near dead?

Michael

[thedhgroup]

Originally Posted by planete

What exactly did you do to bring your car back from near dead? Also, how long has your car been near dead?

Michael

If the SOC were at 19 bars any assist around 10 seconds would trigger a negative recal. I'm thinking that if I would have gone much longer like that the IMA light would have come on. After the first time I balanced it I saw much better performance. After my 7th balance I could get tons of assist and I don't get negative recals anymore. So I think my pack was severely out of balance. Now I just bulk charge and I try to get in a balance every 3 weeks or so.

[planete]

Originally Posted by thedhgroup

If the SOC were at 19 bars any assist around 10 seconds would trigger a negative recal. I'm thinking that if I would have gone much longer like that the IMA light would have come on. After the first time I balanced it I saw much better performance. After my 7th balance I could get tons of assist and I don't get negative recals anymore. So I think my pack was severely out of balance. Now I just bulk charge and I try to get in a balance every 3 weeks or so.

Thanks for the info. My IMA light was on for 3 days before I removed the negative wire from the 12 volt/ replaced the wire and reved the engine to 3500 rpms a few times. the IMA light is off for now. Wonder if grid balance or charger would postpone my bb investment?

[thedhgroup]

Originally Posted by planete

Thanks for the info. My IMA light was on for 3 days before I removed the negative wire from the 12 volt/ replaced the wire and reved the engine to 3500 rpms a few times. the IMA light is off for now. Wonder if grid balance or charger would postpone my bb investment?

I think I and many others believe that if Honda would have designed a way for technicians to balance charge our cars once or twice a year, many of us would have gotten many more miles or years out of our packs. Now it is up to us.

The investment for a charger needs to be made sooner or later. You need one if you want to keep either your old pack for a while longer or to keep a new pack healthy. You don't need one if you intend to sell your car soon.

[Rush]

I'm not sure how to tell a Neg recal from a Pos recal - can someone explain?

[Eli]

A negative recal is when the pack goes from say, 10 bars to empty.

A positive recal is the opposite - the pack will go from 10 bars to full.

It's easiest to see when the "bar swing" is large like that, but with the OBDIIC&C Gauge you will see that the car negative and positive recals all the time, I call these "benign recalibrations".

For example, from 28% to 25% on the bottom end and from 72% to 75%(or 81% depending on your BCM revision) on the top end. If your pack is healthy.

If your pack isn't so healthy, you can see positive recalibrations in the 60% SoC range, which is 18 or 19 bars - difficult to detect from the dash cluster alone.