Extra battery connection

[gisli]

I am working on a project with I-Miev car, I have built 6 kWh removable battery to extend the range of the car.

I connected the extra battery with 322 V direct to the motor inverter. The car at that moment was in "Ready mode" with car batteries exactly at 322 V. My plan was to charge the batteries together in parallel connection. Then I turned the car to ACC and LOCK mode to charge it.
But it didn´t charge. After unplugging my extra battery the car is still not charging and does not come to "Ready mode".

I guess that when the car status changed from Ready to ACC mode the motor inverter still had the extra battery connected with 322 V, then the EV/ECU detected an error that creates the actual situation.

I have the OBDLink LX adapter and use the CaniOn and EvBatMon apps.

Does anybody knows any app to read error codes from the EV/ECU?
Does anyone have experience using MUT3 to read and erase error codes?
Has anyone bought a Chinese version of MUT3?

 

[kiev]

Welcome to the forum. Where are you located? Does your car have the Chademo charge port?

That is a very interesting experiment you are doing, please share how you get this resolved.

You may want to look thru the forum on previous experiments by other members and how they did this.

Good luck to you.

 

[Don]

I guess that when the car status changed from Ready to ACC mode the motor inverter still had the extra battery connected with 322 V, then the EV/ECU detected an error that creates the actual situation.

I would guess that . . . . you're probably right - You did something the car didn't like, which was probably predictable. Exactly what that might be is a good question. I hope it doesn't turn out to be expensive to resolve. Hopefully it's just an error which needs to be reset and not something you've burned up

Do you have a dealer nearby who can connect the MUT3 and give you a definitive answer? I think that would be a smart next move

Don

 

[JoeS]

Gisli, understand what you did and admire you for trying. I am so sorry the car reacted this way.

It is a pity that you were not able to attach your external battery directly to the i-MiEV's active (pre-contactor) HV terminals - I presume you do not have CHAdeMO?

I believe what happened the moment you turned the key back from its READY position is that the car detected what it thought was a stuck main contactor (as evidenced by the 322v still being present) and considered that a fatal flaw and disabled the car in addition to throwing an error code.

To answer your question, neither the CaniOn nor EVBatMon developers have openly tackled the issue of either reading the codes nor resetting them. You might contact Martin (me68) (developer of CaniOn), Xavier (priusfan), and zzcoopej (developer of EVBatMon) to see if they have done some behind-the-scenes work which may help you.

As far as I recall, no one has actually managed to get their hands onto an operational Mitsubishi MUT3 nor successfully managed to get a MUT3 clone to work.

I wish you all the best in this endeavour.

 

[DonDakin]

Have a look at this video link. This guy did something similar with his leaf. Similar problem.

I think he blew the precharge resistor. Not sure if this is the case for your car but maybe it will give you some ideas.

Don.....


https://www.youtube.com/watch?v=6Zivzvh9Bx0&t=17s

 

[PV1]

How long was the external battery connected after taking the car out of READY?

The car will throw a code if the HV bus doesn't de-energize fast enough, which is exactly what would happen with an external battery connected. At the least, leaving the car sit for a while will clear the code, but at the worst, the discharge resistor blew out.

Leave the car off and measure the HV connections where you attached the external battery. What voltage does it read?

 

[gisli]

[/quote][/quote]

Welcome to the forum. Where are you located? Does your car have the Chademo charge port?

That is a very interesting experiment you are doing, please share how you get this resolved.

You may want to look thru the forum on previous experiments by other members and how they did this.

Good luck to you.

I am in Iceland. Yes it has Chademo charge port but I haven't try it. It is not easy to bring the car to the charging station

 

[gisli]

I guess that when the car status changed from Ready to ACC mode the motor inverter still had the extra battery connected with 322 V, then the EV/ECU detected an error that creates the actual situation.

I would guess that . . . . you're probably right - You did something the car didn't like, which was probably predictable. Exactly what that might be is a good question. I hope it doesn't turn out to be expensive to resolve. Hopefully it's just an error which needs to be reset and not something you've burned up

Do you have a dealer nearby who can connect the MUT3 and give you a definitive answer? I think that would be a smart next move

Don

I have, I will do, but first I wanted to check if there is any possibility to read this error code myself, specially because it might happen to me again in this project.

 

[gisli]

Have a look at this video link. This guy did something similar with his leaf. Similar problem.

I think he blew the precharge resistor. Not sure if this is the case for your car but maybe it will give you some ideas.

Don.....


https://www.youtube.com/watch?v=6Zivzvh9Bx0&t=17s

Thank you. Do you know if he manage to solve the problem by repairing the precharge resistor?

 

[gisli]

How long was the external battery connected after taking the car out of READY?

The car will throw a code if the HV bus doesn't de-energize fast enough, which is exactly what would happen with an external battery connected. At the least, leaving the car sit for a while will clear the code, but at the worst, the discharge resistor blew out.

Leave the car off and measure the HV connections where you attached the external battery. What voltage does it read?

The external battery was connected around one minute.
I measured the HV connections and it is 0 V.
I have disconnected the 12 V battery over night and it does not solve anything.
Discharge resistor, is it the same as the precharge resistor or is it another?

 

[PV1]

There are two resistors. The pre-charge resistor is located inside the battery pack. It is used to slowly bring the high-voltage bus up to pack voltage when starting the car (slowly being 1-2 seconds).

When the car is shut off, a discharge resistor, located in the Motor Control Unit (MCU, also known as drive inverter), will slowly (over about 10 seconds, I believe) bleed off all voltage on the HV bus after the battery pack disconnects.

Given that it read 0 volts, I don't believe the discharge resistor burnt out, so good news there. The only thing the dealer should have to do is reset the code and you should be good to go.

In previous discussions on this forum, myself and others have stated to use contactors to disconnect 2nd battery packs. The contactors should get their power from the same feed that drives the main pack's Positive (+) contactor. This way, the 2nd pack won't connect until the HV bus is charged and the main pack connects. It will also allow both packs to charge together and be connected/disconnected at the same time, and would hopefully avoid this issue going forward.

 

[gisli]

GOOD NEWS!

I managed to reset the error WITHOUT the help of the local dealer, thanks to this diagnostic tool :
http://www.diagnostic-world.com/pages/mazda_code_readers_189127-z=563744&p=105904.cfm#content_item_105904
Now I don´t have to worry about producing more error codes as I can always reset them myself.

The extra battery is now connected and has been charged in parallel connection to the main battery. Now I am connecting some measuring equipments before I do the first "hopefully" long test drive. I will post the results.

 

[kiev]

Wow, that is great news. i'm glad you found a tool that would do the reset. does it also reveal any of the stored information from the car's memory, etc. over the can bus/diagnostic connector? Thanks for sharing, all info helps gain a better understanding...

 

[JoeS]

Fantastic! Thank you gisli. Where did you end up connecting to the main battery?

I got this far in pursuing the i909 unit, available for NA i-MiEVs, but haven't finished reading the fine print. No time now...

http://www.icarsoft.com/web/icarsof...antools/2012/201212/2012122912256kg3yn_1.html

 

[siai47]

You Cannot connect the additional battery to the inverter as you are bypassing the main contactor which is located in the battery pack. Bad things will happen unless you have a way to connect the additional pack after the "ready" light is on and disconnect it before the "ready" light is off. In addition, the I-MiEV battery is a lot higher voltage (just over 360 volts when fully charged) than the 322 volt battery you are using. I don't know what type of batteries you are using but if Li-Ion you will surely be overcharging them to a dangerous level. The only correct place to tap into the battery is inside the pack before the contactors. Or, if a Chademo equipped car, through the Chademo power cables. The codes you got most likely were because the car thought the main contactor was stuck closed. Remember, there are lethal voltages inside the pack so I am not recommending you go inside. However, if you match the voltages, the external pack will work if wired correctly---I have done it.

 

[gisli]

Wow, that is great news. i'm glad you found a tool that would do the reset. does it also reveal any of the stored information from the car's memory, etc. over the can bus/diagnostic connector? Thanks for sharing, all info helps gain a better understanding...

Yes, the unit can read error codes and clear them. It has also the "read data stream" function where I can see values from all the sensors in the car.
About the stored information in car´s memory, at least I have seen data from the BMS like the actual Ah capacity of the battery.

 

[gisli]

Fantastic! Thank you gisli. Where did you end up connecting to the main battery?

I got this far in pursuing the i909 unit, available for NA i-MiEVs, but haven't finished reading the fine print. No time now...

http://www.icarsoft.com/web/icarsof...antools/2012/201212/2012122912256kg3yn_1.html

I am still connecting directly to the motor inverter but I only switch the extra battery on when the main battery is switched on. I am doing this manually but later I will add a relay that is controlled with the same signal as the main battery relay.

 

[gisli]

You Cannot connect the additional battery to the inverter as you are bypassing the main contactor which is located in the battery pack. Bad things will happen unless you have a way to connect the additional pack after the "ready" light is on and disconnect it before the "ready" light is off. In addition, the I-MiEV battery is a lot higher voltage (just over 360 volts when fully charged) than the 322 volt battery you are using. I don't know what type of batteries you are using but if Li-Ion you will surely be overcharging them to a dangerous level. The only correct place to tap into the battery is inside the pack before the contactors. Or, if a Chademo equipped car, through the Chademo power cables. The codes you got most likely were because the car thought the main contactor was stuck closed. Remember, there are lethal voltages inside the pack so I am not recommending you go inside. However, if you match the voltages, the external pack will work if wired correctly---I have done it.

The extra battery is based on Li-Ion cells Sanyo NCR18650GA 3500mAh - 10A, connected 88 Serial and 6 Parallel that is exactly the same number of cells in series as in the car battery pack.
The 322 V was just the charging status of the extra battery and of the car battery when I connected them in the beginning. Now I have fully charged them in parallel and both packs are approximately 360 V.
I think it will be ok to connect directly to the motor inverter as long as I switch on the extra pack only when the car battery is switched on.
I am not connecting through the Chademo power cables because later I am planning to be able to run the car either on the extra pack or the car batteries or both in parallel. With the Sanyo cells I am able to pull 60 A according to the cells data sheet. Therefore I can drive the car with power up to aprox. 18 kW only with the extra pack. This pack is around 5 - 6 kWh so it should give aprox. 50 km extra range.

 

[richijennings]

Sorry to dig up an old thread, but I wondered how @gisli got on with this project. Hopefully he didn't electrocute himself.

I'd love to know.