Honda Insight Forum banner
1 - 20 of 22 Posts

·
Premium Member
Joined
·
1,039 Posts
Nice catch Doctor_Zoidberg. You are correct it does look like he needs to reverse that last battery.

I am trying to figure out what exactly will happen if he leaves it like this?
 

·
Premium Member
Joined
·
1,039 Posts
If you completely bypass the Interceptor, does the car work and start normally?

If not, the first thing I would do is start putting the car back to normal by removing any of the modifications you have done. Its probably a bad connection someplace. Obviously you can't remove the fooler but you can easily check the voltages.

.1% resistors are probably a waste, I would check the voltages of each of the wires to make sure the voltages are all the same or within .01 volts of each other.

I was always worried about those MCM and BCM connectors, I tried to never pull those out by the wires. Do you pull those connectors out of the MCM and BCM by the wires or the plastic housing?

I would get a resistance ohm meter and check all the wires and pins in the connectors. check the 20K pots you have.
 

·
Premium Member
Joined
·
1,039 Posts
Honestly, if you have an LTO pack you should cut both wires. It seems not many people want to cut the Green/Blk wire but that will allow you to sit in the car, turn the key to the ON position, and be able to run your radio and lights without the car battery draining.

As the car is setup now if you try and listen to the radio in the car with the key in the ON position, but the engine not started, the 12 volt battery does not charge. Which is such a stupid thing and I was surprised it was setup like this, I always expected it to always charge the 12 volt in the ON position.

I would assume the reasoning for Honda not allowing this is with the crappy NIMH packs these cars came with, there was no way to really be sure what the state of charge of the pack was, and I guess it was too risky to power the DC/DC converter without the engine running to keep the NiMH pack charged. However, with a high capacity LTO pack, there is no reason why you shouldn't have your DC/DC converter always on when the key is in the ON position.

I wonder what would happen if you left the key in the ON position with the lights and radio on. Would that drain your LTO pack down below 1.5 volts per cell?

I seriously can't be the only person who sometimes needs to sit in the car and wait, and wants to listen to the radio without the engine running?
 

·
Premium Member
Joined
·
1,039 Posts
With those resting voltages, I can't say conclusively how much of a difference they make. I wouldn't want to keep the pack sitting long term above 2.4 volts. I also found that letting them drop between 1.5 and 2.0 volts is bad.

I would say, you want to try and keep the pack around 2.3 volts if you wanted optimal life. But again, not sure if it makes much of a difference.

If I remember correctly I think storing them at 2.1 volts seem to be optimal over say 2.2 volts. But the difference wasn't all that much if stored in a cool place.

I do know with regular lithium cells, there is a big difference in how the cells are stored long term. If you store them too high, they will lose capacity at a much higher percentage. Storing a lithium cell fully charged will take about 4% of its life a year. Storing it at 30% of capacity will reduce that to .5% a year. Temperature also plays a reasonable part and probably most of the capacity we will see is from the battery baking in the hot sun in the car. It is probably more important to store the car at lower voltages if its baking in the hot sun.

Another way to look at this is if you over charged a cell to 4 volts, you would probably kill its life. So charging to 2.6 while not as overcharged as 4 volts, is still going to be much harder on the cell than say 2.4 volts.

With that being said, I tend to keep my battery around 2.2 volts when not using the car or when I have it sitting, and only charge it to 2.45 volts before most trips.

The worst thing you could do is keep the battery fully charged. I cringe when I see people who do that and most people do that with all their batteries. I tell my father if he uses a cordless drill, to not charge it afterwards if he is not going to use it for a long time. Charging it to 100% and letting it sit will reduce capacity about 3-5% a year vs .5% if stored at a lower voltage on most lithium chemistries.
 

·
Premium Member
Joined
·
1,039 Posts
Question if anyone can clarify:


My IMA battery cut out the DC/DC converter at 145 volts when I had the key in the ON position but the engine off. I have the wire cut so I can run it like this.

It was mentioned that the NiMH cuts off at 120 volts, but not sure if that is under load or resting.
 

·
Premium Member
Joined
·
1,039 Posts
I had the same issue with mine and even made a thread about it a while back. Its quite annoying.

The only way I solved this issue was disabling coast regen. Coast regen will always keep your battery fully charged.

You may be able to try and use the IMA Boost and current hack to help, but the current hack will also increase the coast regen amperage and will cause such a drag on the car that you will feel like you have a flat tire every time you are coasting.

The best thing to get rid of this issue is to disable the coast regen, but its not exactly easy thing to do. You would need the IMA Boost. I just love coasting without the coast regen.

You could of course be very vigilant and throw the car in neutral every time you remove your foot off the gas, but that is not something I'm going to do.
 

·
Premium Member
Joined
·
1,039 Posts
retepsnikrep, but even if he moves the voltage down, will he not still have the same issue of the pack that continues to keep over charging?

I think the main cause of the issue is too much charging and too little discharging. The insight was built around NiMH which has a large self discharge, meaning it loses about 10% a week of capacity by just sitting. The NiMH is also probably a lot less inefficient.

What happens is the insight does not work well with an LTO pack which is highly efficient and doesn't self discharge.

The only way I solved this issue was by losing the coast regen. The Coast regen is actually something you do not want if you have an LTO setup, especially if you are grid charging the pack. You really do not want the car to start charging every time you take your foot off the gas. First its annoying, and 2nd its inefficient.

What he really needs is my modified IMA Boost, this would allow him to switch coast regen on and off. This would allow him to keep the Coast regen disabled and get a much nicer drivable car with no drag and better MPG, and then if he needs his battery to charge because he can not grid charge the car, then simply turn the coast regen back on and charge the battery back up by a flick of a switch.
 

·
Premium Member
Joined
·
1,039 Posts
I read it that he doesn't have the ceiling, meaning his pack is at too high of a voltage most of the time. I had this same exact issue and even made the following thread.

I think the issue is worse if you drive inefficient by constantly speeding up and then taking your foot off the gas instead of holding a constant throttle speed.

In this thread you made the 2nd post, basically saying what I wrote in this thread. I think I learned the problem from your 2nd post and realized there wasn't much I could do about the issue unless I do things to limit charging and increase discharging of the pack.

You can read my thread from 2017 below about pretty much the same issue:

 

·
Premium Member
Joined
·
1,039 Posts
retepsnikrep: I just don't see how changing the voltage with the vpin and pre-resistors would help him. Those things should only be adjusted so that the LTO battery works within the insights voltage constraints.

Lets assume minors 72 cell pack is reaching 180 volts maximum with the current vpin and pre-resistors. At 180 volts pack voltage it should turn off regen.


His issue is 100% too much charge and too little discharge. Messing with the VPIN & pre-resistors to try and increase his pack voltage above 180 volts would only make him overcharge the pack.

Minor has no way around it except to increase assist with the IMA Boost. Or what I do is turn off the coast regen. There is simply no way around his issue, he will always be overcharging the pack unless he changes his driving habits drastically to use more assist and less regen.
 

·
Premium Member
Joined
·
1,039 Posts
One thing I wonder about is, why isn't everyone who did a lithium ion conversion complaining about this issue? I had the issue, it seems Minor has the same issue.

What about all the other people who did LTO conversions, they don't seem to be complaining about the regen issue.

It is possible that many of them are using a joystick to control the assist, but I doubt that.
 

·
Premium Member
Joined
·
1,039 Posts
I would think the issue is more how you drive then BCM/MCM related. I may have bad driving habits in that I constantly accelerate and then take my foot off the gas to slow down, than accelerate again to get back up to speed. I do not hold my gas pedal down at a constant speed. This caused my car to constantly coast regen charge.

On the highway, I had much less of an issue with an overcharged pack.


The simple solution is the IMA Boost, this will cause the car to use more assist through the RPM range. Optimally one would want to modify the IMA Boost to turn off coast regen and that will 100% solve this issue.
 

·
Premium Member
Joined
·
1,039 Posts
How long was that 10 amp background charge going on for?

I wonder if your pre-resistors are not set up correctly and your car thinks the pack voltage is too low.

The other thing it could be is are you using the upgraded Interceptor software that has qbatt? Peter has been messing with the software to try and charge your pack at certain levels. Who knows what it could be doing if you are using that modified software as its not been perfected and it also requires your pre-resistors to be setup correctly.

You would have to give us this information.
 

·
Premium Member
Joined
·
1,039 Posts
If he has the current hack that may increase it to 11. I know my background charge is around 10 amps using an amp meter, but that is when I have a few green bars and using Qbatt to force a background charge. I didn't know that you could get a 10 amp background charge and it not show up as green bars.

This is why I keep my setup simple, BCM Interceptor with the software that sets everything for maximum power. Then I use a simple single cell volt gauge to know exactly my battery pack voltage.

Using an 84 cell setup, I set the fooler pre-resistors and Vpin, so that my battery cuts off around 2.00 volts per cell. Luckily, since I can't set both my low voltage and high voltage cutoffs, my regen gets cutoff around 2.5 volts per cell, and that alerts me before my battery gets overcharged.

If I needed to charge up my battery, I will just use Qbatt and get a background charge going when I need it.

This setup gives me everything I need, and is quite simple and is also less likely to suffer any software glitches as its based mostly on the cars battery management system. Using a single LTO cell as battery voltage will also give you the easiest and most precise way to monitor your pack voltage.
 

·
Premium Member
Joined
·
1,039 Posts
eq1, I think the single cell voltage is honestly the best way to monitor your pack voltage. Not too many people seem to think so, especially in the ebike community, I've argued with some of the guys who design the ebike controllers to offer an option to display a single cell voltage, but they never go for it.

What I like about it is all your cells should be in balance, so you really want the easiest way to know whats going on at the cell level.

It is much easier to think of your battery pack in terms of a single cell, and you should be really familiar with exactly how capacity is related to voltage. With LTO you know that 2.00 volts your pack is pretty much empty and you need to be cautions, at 2.5 volts your pack is very full and you have to be very cautious. You normally want to keep your pack around 2.3 volts for optimal longevity.

Thinking in terms of a single cell voltage allows your brain to more easily determine the cell voltage and the capacity, instead of converting from a pack voltage to a cell voltage.

It also allows you to switch between packs of the same chemistry and more safely know your pack capacity, switch from a 72 to 84 pack, you know exactly your pack voltage with the single cell voltage,.

You want to discuss your battery pack with other people, using cell voltage makes it much more easily understood instead of saying 170 volts.

Another big benefit is that you can easily run a very cheap and precise volt gauge to the front of the car safely, something you don't want to do with a 170 volt line run to the front of the car. This x.xxxx volt gauge really gives you precise feedback what is happening with your pack, is it charging , discharging etc.

single cell voltage is honestly so much better, but I'm yet to really meet anyone else who sees the advantages of it. Most people like to see the full pack voltage, which to me is not advantageous. I guess this is because they are used to the full pack voltage, which will work well, but takes more brain processing power to really know what is going on at the cell level.

I have two volt gauges run to the front now, one is actually for my 12 volt LTO battery and the other is for my pack voltage. I didn't do the single cell for my 12 volt pack because this voltage is always constant at 14.2 volts, and I didn't want to confuse myself having two single cell gauges next to each other.


 

·
Premium Member
Joined
·
1,039 Posts
minor, what BCM interceptor software are you using? I would not install any software that does any background charging until you figure out what is causing your issue.

How often are you having this problem, are you not able to regen sometimes, or most of the time?

If your regen is cutoff, your pack voltage should fall fast and you should get regen back quickly.

the stock NiMH pack was always in a discharging state, it also was probably not that efficient charging, the cells heated much quicker causing more waste. LTO cells are always cold and never seem to heat up. Honda designed the battery management to deal with the highly inefficient NiMH cells and my insight was always in a discharged state when using them.
 

·
Premium Member
Joined
·
1,039 Posts
Yup, its simply like calories in / calories out. Too many calories in and not enough calories out, you get fat.

Your battery is simply taking in too much regen and not using enough assist. I had the same exact issue with my pack.
It is highly unlikely your battery pack is background charging without bars, you should try and figure out if this is happening if you saw it happen at higher pack charge voltages.

The only easily workable solution is the IMA Boost, unless of course you want to drastically change your driving habits like flooring the car constantly on the highway and then putting the car in neutral. Or possibly using a a joystick to control the assist manually.
 

·
Premium Member
Joined
·
1,039 Posts
^ That's not true at all - the OEM NiMH cells, when they're in good shape, have a very very high coulombic efficiency - like >95%. They hardly heat at all. I actually calculate more like 99%, but that's so good, and it's based on the pack's current sensor, that I have to be skeptical.
First you are comparing the NiMH pack of about 1KW to a 4KW LTO pack. When I ran a voltage sag test on my NiMH sticks vs LTO cells, it was like 2 volts NIMH sag vs .2 volts LTO sag, per 12 volts. The NiMH sagged about 10x more than my LTO pack at not a very high current. With less voltage sag, the insight will draw less current and less current losses.

The LTO is much more efficient, especially because we are talking 3x the capacity. The LTO is also more efficient at the same capacity.

The LTO packs are also much more efficient when charging. You can charge LTO packs at the same rate I believe as max discharge. The NiMH packs are rated at what half charge to discharge?

LTO also doesn't self discharge at the rate of over 10% per week.

I'm not sure how much this all matters, but it must have an impact. Even if NiMH seems good, we are talking about 3x more capacity to deal with the discharge and charge.
 

·
Premium Member
Joined
·
1,039 Posts
Ahhh, I kind of figured there was something with that background charging and the BCM Interceptor software Minor was using.

I am using the original version of the BCM interceptor software that sets the SOC all the time at 75%?? and that is why I never have any background charging. It will be interesting if that fixes his issue.

This setup is exactly what you need for an easy way to control your battery level of your pack, LOL.

Qbatt and IMA Boost both combined with a control panel to easily change settings.

I can do the following from the control panel:

Adjust assist strength
Adjust regen strength
Enable background charging
Disable Assist
Disable Regen
Enable Coast Regen
Disable Coast regen
Allow maximum assist or regen to 100% by pushing a button

 

·
Premium Member
Joined
·
1,039 Posts
minor, what I did was build my own control panel to control the Qbatt and IMA Boost more easily. What I wanted to avoid was having the mess you see in the picture. This mess was only suppose to be temporary as I wanted to make sure everything worked, then I just never got around to tidying it up.

I finally have the time to work on these projects after my corona virus layoff, which I'm happy to have gotten layed off, as I finally have some time to do my projects and hobbies.

I intend to mount the control panel by hot gluing it to the console in front of the emergency brake lever. Then I will mount safely mount the Qbatt and IMA Boost under the dash someplace and safely away.

I like the IMA Boost because it offers easy control of assist and regen levels. I use my insight mostly as a PHEV and use max assist, but if I'm doing a long highway trip I turn down the assist on the highway, then usually turn it back up when I'm off the highway.
I also don't like coast regen because of the regen drag, especially with the current hack and 84 cells, and since I use my insight as a PHEV, turning off coast regen allows higher MPG.

You can see the mess in the picture is why I made the control pod. Normally I would have to reach down there and feel for the pots or buttons when making adjustments. I'm surprised I never broke or shorted anything.

The OBDIIC&C is the next thing I need to work on, I have just used that briefly to test.
 
1 - 20 of 22 Posts
Top