Owl, this is exactly how my car acted after charging my battery for the first time. You will probably have a recal next time you drive it. Then another the next time you drive it. And then more and more. Since your battery was much worse than mine, hopefully it doesn't return all the way to doing recals as often as it was. Mine did, but that's about 3 per day. Usually one first thing in the morning before I get a block from home. One again if it's parked for an hour or so. And maybe another one if I drive up a medium size grade where it uses IMA for 10 seconds or so. Maybe it'll recal after I get up to highway speed mergining onto the "freeway" (as they like to call them here). I've connected wires to my battery like Ross did so I can connect my charger every day. I charge it for 20 minutes or so at 1 amp then knock it down to 300mA for how ever long it takes me to decide to go somewhere. I don't see any recals when I do that. I drove it 180 miles yesterday. 90 miles to see my family then the car sat all day. Then I drove home the other 90 miles. There is a hill I must get over to get there and I didin't get a recal going to my family gathering, but on the way home I did get one recal after I crested the hill. This is a big grade that is probably 5 miles long one way and 2 miles the other. It's not especially steep, but it's long. I'm happy with those results. The IMA battery charged up quick while traversing down the hill so I didn't loose any fuel effeciency. Good luck with it and please keep us in the loop on the progress you're having.

 

Owl: Thanks for sharing your experiences as well. Hope someone can drive your car at least once every 30 days (says to do that in my owners manual) to keep the battery topped up.
Cheers
Mike

 

All good stuff Owl! I hope things continue as they are. I do believe you get a benefit from occasional "top-offs" to re-ballance the battery. You'll likely have to do it again this summer when you return... then you can really put it to the test.

Regards all!

Ross

 

Question for rossfree, jeep_daddy and/or any other person that has been following this thread:

The two wires (with diodes) that are attached to the IMA battery for connection to the home made 350 mAmp trickle charger.....

When the two wires are attached to the IMA battery in the fashion described earlier in this thread, are the ends "live" or does the diode set-up (and one way valve action of same) create a situation where there is no voltage potential that can be measured at the 'loose ends' of those two wires?

Reason I ask: Once my warranty period is up (and even if I get a new IMA battery) I am going to set up the trickle charger mentioned earlier in this thread.

I would like to do it the following way: Have the trickle charger built into the car and always connected to the IMA (via the discussed wire/diode set-up). I would route the 120 volt "plug wire" in such a fashion so as it would terminate in front of the lower front grille, much like a block heater plug. When I would use the charger, I would simply plug the car in like a block heater.

Comments? Dangers? Is my concept possible? Would I employ in-line fuses as well as the diodes for another layer of safety? If so, what kind of fuse for the IMA voltages (and trickle charger amps) involved?

Thanks

Cheers

Mike

 

Every time you do this 'plug-in' trickle charge to the attached battery, you would have to pull the 12V battery cable also, or you risk seriously overcharging the IMA battery. So this would only make sense if you did it once in a while to recondition the battery.

With NiMH batteries, you can't rely on voltage to tell the charge level. It has to be done by measuring current in, and current out.

So the HCH would not know the charge level unless you pull the battery and it does a re-cal to determine charge level.

With Lithium ION its much easier to do 'plug-in' since the charge level can be determined by voltage alone.

All of the Honda trickle charger articles I've read require you to pull a fuse or battery cable before you do the trickle charge, so I believe the above is the reason why

 

Diodes allow flow one way. It will allow flow to the pack. I would personally treat them as live wires myself. I hate electricity! H

 

Hunter & Harold, thanks.

Discussion:
OK, I understand the concept to isolate the normal 12V battery to cause a re-cal upon next re-start. It really does seem rather rudimentary how the SOC system works in this car....

I thought that at 350 mAmps, the individual stacks would charge to the point they begin to dissipate heat and as long as one manages the heat (i.e. such a low amperage in) that there would be no issue to seriously overcharge this battery pack. Am I mis-informed on this issue?

This would be my aim, a once a month re-condition if you will. Since it seems that one must isolate the 12 volt battery, then one might as well have the 'plug' (I would use a standard Honda connector between the recharger and the battery pack) for the two non OEM wires somewhere such that its length is short (for safety) but still accessible.

Where have others stowed the actual connection point?

Agreed. So I am looking to make my two non-OEM wires, with a Honda connector on the end, short enough for simple, safe storage. I think I may also get orange colored plastic cable wrap (to mimic the auto industry standard of wrapping any high voltage hybrid cables in orange) so that for any (unintended) reason anyone seeing said wire wrap will treat it with respect (reason why I asked if those two non OEM wires, even with the diodes, are "live" if cut/touched/etc)......

Thanks guys.

 

Hunter, Ross, Nav, Harrold - I have really enjoyed this thread as I have truly learned a lot from you guys - especially from Hunter about how to R&R, recondition, disassemble, reassemble and install the diodes. Thank you. But I must say, after doing some of the experiments discussed in this thread I've found that charging my battery as prescribed did and does NOT repair the battery in any way. I've charged it at 350mA all night; I've charged it at 1A for 2 hours; I've tried charging it many times and by the next day, sometimes two days, it always goes back to acting exactly the way it did before the experiment.

Now I charge my battery every morning at 500mA. When I wake up, I put the charger on and then I get breakfast, shower etc., and when I'm ready to leave the house, I disconnect the charger and it works great. The first time I charged the battery I did as recommended and removed the 12v cable for 5 minutes (or longer) so the IMA would recal. Yes, that did cause the IMA to show the battery bar graph at the top. I have not done that ever again because in doing so, it caused my odometer and running average gas mileage totals to reset. I didn't like it when it did that. I've been charging my battery every day now since then and it does not really affect the IMA system like you think it would. If the battery graph was at 6 bars before the charge, it will still be at 6 bars after the charge. The IMA does not charge until the engine is warm enough and the car is driven a few miles, so the system will not overcharge itself.

One time I was in a hurry and charged it at 1A rate for about an hour. I disconnected the charger and drove off. But as soon as the engine started I could hear a fan come on toward the rear of the car. I am sure it was the IMA battery cooling fan that I was hearing. I drove the car and did not get any IMA assist. I stopped the car and turned the engine off. (Just a little experiment) When I restarted the engine the 12v starter engaged and started the engine. I was a little surprised since I had just charged the IMA battery. Also, that is the first time I've ever heard the 12v starter engage. But here's what I figured - the battery got a little warm by charging at the higher rate causing the fan to come on and disable the IMA system until the battery was at a cooler, normal temperature. I drove the car a few miles and had my AC on to help cool the interior of the car and then the IMA system started to work fine. I will avoid charging at the higher rates from now on. I've never had this problem at the lower amp charging rates.

After all this I believe:
1. It is not necessary to do a forced regen after charging - but do it if you charge your battery only once in a while.
2. If the battery is on it's last legs, why not charge it every day if it helps performance and gas mileage - especially if it's out of warranty. What's the worse thing that can happen? you ruin the battery and will need a new battery. Well, you already need a new battery! right?
3. Any form of charging a battery with weak cells is not going to permanently fix it (even charging individual sticks one at a time)
4. Charging the battery at 500mA or less helps, but does not cure all
5. The diodes are a great idea. Without the diodes, you might get a spark, like I did once, when connecting the charger. I don't have a voltage potential after the diodes, so I believe it is safe. If you're worried, put in-line fuses on each charging wire. You can't go wrong. (5A should be ok)

I've heard that Honda will not warrant the IMA battery unless a code is thrown that the battery is bad. I don't know if this is true or not because all dealerships are different and I think it depends on how hard the service manager pushes to get it replaced. I bet that some service managers will go so far as to tell Honda of America that the car HAS a code and that the battery needs replacing. Some will not. I'm just speculating here.

I hope I have not offended anyone here. These are my opinions and what I've observed. I am grateful to those that have contributed to this thread. Thanks.

 

Hey jeep_daddy;
I am one of the lucky ones as my pack is still as it was the day I took delivery.Mind you I only have about 53,000 miles on it and mostly longer drives. Very little bumper to bumper stuff. This maybe the reason for my good luck? This is a very interesting thread. Your comments are interesting. We learn from all experiences ! Thanks and keep us all posted, H

 

jeep_daddy: thanks for your great de-brief with your experiences. As Harold said, we are all learning alot here and the field testing results you have given us are great.

If/when I go with this set-up, I think I'll try with no forced (re-cal) by disconnecting the 12V battery since it sounds like you really did not need to do so.

100% agree, what does one have to loose if you have no warranty.....

This is the info I'm looking for as I really want the two non-oem wires to be 'safe'. The 5A fuses you mention, is that a standard 12V automobile 5A fuse (I know the charger will only be 350 mAmps, but please confirm) or a 5A fuse for something at 220 volts?

I agree with this opinion as the facility I will be taking my car in for 'show and tell' next week is twice as far from my home as the dealer who sold me the car. The service manager I now/only deal with has always been very honest and straight up about any issues I have brought to his attention.......so much so that his dealerships catch basin extends from Whitby ON to Kingston ON (about a two hour drive on HWY 401 between those two cities.....