# Think PIV4/City/Classic upgrade



## prensel (Feb 21, 2010)

Hi all,

I'm upgrading (not converting since it is already an E.V) the Think PIV4 also known as the 'Think City' or the 'Think Classic'. 










These little 2 seater cars were build in Norway around 2001 and a lot of them went to the USA under the name ' Ford Think City'.. and they all came back in 2005 or 2006 when Ford decided that E.V's where (again) not the way to go...

https://www.youtube.com/watch?v=uJBlZzihc_M

A lot of these cars are scrapped in the past years so only a few are left (mainly in Norway). 



Originally it's equiped with 19 Saft 6V Nicad cells, so nominal 114V/100Ah. Has a Siemens drivetrain, PTC heater and a lot of other common Peugeot/Citroen mechanical parts. 

The batteries are inside a 87cm x 75cm centralized batterybox under/inside the floorpan.
I have removed the old Nicad cells and cleaned the batterybox from all unwanted metal to make room for a full 24kWh Nissan Leaf battery. 
With 24 modules in one stack and some modified endplates each stack is 35cm x 86,5cm and two of these fit perfectly inside the box with some room left for relais etc.  

Since the Siemens inverter can only handle upto 385V and the original DC/DC upto 290V I have decided to 'break' and parallel the Leaf pack into a 196V pack. So instead of 48 modules in series I will parallel each two modules to get 24 modules in series. (each module is allready 2S2P).

The original battery had a 'BMS' and a contactorbox with pre-charge and main relay and some other functionality like cabin pre-heater, delayed/timed charging etc. By keeping the voltage under 200V I can almost certainly re-use all this functionality and re-use all HV components. 

Although the firmware/software of the Siemens inverter is locked with a code that Siemens has to provide I managed to crack the code and can now make modifications with Siadis, the Siemens MS-DOS software. This opens the possibility to change setings like max Amps, Volts, top speed etc.

Why upgrading to a bigger battery:

https://www.youtube.com/watch?v=JcuDCZMmCKg


----------



## prensel (Feb 21, 2010)

Breaking up the Leaf battery.

Since I have decided to break and parallel the Leaf pack from 48S into a 24S pack I needed to create new/other module connectors/busbars. Made from 1mm copper strips that came from an electric building/powerplant, cut into smaller 20mm strips of 120mm each, punched 4 holes of 7mm in each so i can parallel and series connect 4 modules.










Heres the first protoype build of one stack:










For the monitoring I'm using Zevan BMS modules. Two modules on each stack for 24 cells.

And two of these fit perfectly inside to original battery box:










Prototyping and testfitting a terminal cover made from 1mm plastic


----------



## prensel (Feb 21, 2010)

Terminal covers finished, made from 2mm Lexan:


----------



## CanadaLT28 (Oct 15, 2011)

Very cool, I will need to re-arrange the Leaf batteries for my VWLT truck project too.


----------



## brian_ (Feb 7, 2017)

CanadaLT28 said:


> Very cool, I will need to re-arrange the Leaf batteries for my VWLT truck project too.


Since you're using a Leaf motor, I assume that you still want all modules in series - as in a stock Leaf - so you are only physically re-arranging the modules. To do that you will need some new connectors, but you won't need these 4-terminal paralleling bars. Right?


----------



## CanadaLT28 (Oct 15, 2011)

brian_ said:


> Since you're using a Leaf motor, I assume that you still want all modules in series - as in a stock Leaf - so you are only physically re-arranging the modules. To do that you will need some new connectors, but you won't need these 4-terminal paralleling bars. Right?


Correct. I will be packing them into rectangular battery boxes with the aim of eventually having a 48kw, one on each side of truck, under the bed, perhaps on rollers. I may need the 4 bolt connectors as the form factor will be similar to the fellow above. I haven't got that far yet. I will make a heating and cooling system for them as well which is not hard for me as it is my trade.


----------



## prensel (Feb 21, 2010)

I got my Leaf pack from Norway and it had heaterplates on each battery stack. I think its a 'cold-weather' or 'winter' option in these countries when ordering a new Leaf.


----------



## CanadaLT28 (Oct 15, 2011)

prensel said:


> I got my Leaf pack from Norway and it had heaterplates on each battery stack. I think its a 'cold-weather' or 'winter' option in these countries when ordering a new Leaf.


What are the dimensions of the battery pack in the picture? I need to start planning the boxes for mine.


----------



## prensel (Feb 21, 2010)

CanadaLT28 said:


> What are the dimensions of the battery pack in the picture? I need to start planning the boxes for mine.


L865 x W340 x H260mm 

I have used 25x25mm angled iron to build end 'plates' and have a support frame underneath the modules to let them rest on it. I'm going to fill up these spaces with high density styrofoam isolation plates of 25mm. Another option is to use these spaces to accomodate for heater or chiller plates. Maybe bent a 15mm copper pipe in meander pattern to allow for coolant ?


----------



## brian_ (Feb 7, 2017)

CanadaLT28 said:


> What are the dimensions of the battery pack in the picture? I need to start planning the boxes for mine.





prensel said:


> L865 x W340 x H260mm


The width (340 mm) and height (260 mm) are the size of a module; each module is 35 mm thick so a stack of 24 (half of the Leaf pack) is 840 mm (plus end plates and other hardware); the stock Leaf pack includes a stack of 24 like this under the rear seat. You need to allow room for the electrical connections, which I think are on the 340 mm long edge of the module.


----------



## brian_ (Feb 7, 2017)

CanadaLT28 said:


> I will be packing them into rectangular battery boxes with the aim of eventually having a 48kw, one on each side of truck, under the bed, perhaps on rollers. I may need the 4 bolt connectors as the form factor will be similar to the fellow above.


If you have 48 kWh that's two full Leaf packs, or 96 modules. You can configure that as

two 24 kWh 48-module sets in parallel, or
parallel them in pairs at the lowest level like prensel has (so you would need the 4-hole connectors), and run 48 pairs in series.
The BMS approach chosen will likely influence that choice.


----------



## CanadaLT28 (Oct 15, 2011)

brian_ said:


> If you have 48 kWh that's two full Leaf packs, or 96 modules. You can configure that as
> 
> two 24 kWh 48-module sets in parallel, or
> parallel them in pairs at the lowest level like prensel has (so you would need the 4-hole connectors), and run 48 pairs in series.
> The BMS approach chosen will likely influence that choice.


I will be starting with one, and will be using the OEM BMS with the possible exception of a bespoke battery heat/cool. I definitely like Prensel compact configuration.


----------



## CanadaLT28 (Oct 15, 2011)

prensel said:


> Hi all,
> 
> 
> 
> ...


I may need your help in working with the BMS, if you are OK with it.. I'm far from a software guy unfortunately.


----------



## prensel (Feb 21, 2010)

CanadaLT28 said:


> I may need your help in working with the BMS, if you are OK with it.. I'm far from a software guy unfortunately.


I'm not using the original Leaf BMS but one from Zeva (zeva.com.au).
Its an almost plug and play system without software skills required

The original Leaf BMS seems to work ok though but not the complete CAN protocol is known yet or easy to find out within a reasonable amount of time. I gave up after a few weekends diagnosing the CAN traffic but couldnt find the info i definately needed to have.


----------



## prensel (Feb 21, 2010)

So after a few days of tinkering the new Nissan Leaf based battery pack is finally installed in the little Think. Its a perfect fit and after initial adjustments to the Simotion controller the car runs very well. Originally it runs at 114V and now with the 48 Leaf modules on 194V but still has about the same 'performance'...










It's time to speedup/tune things.. 
After modifying the inverter's current parameter from 100A to 225A the power went up from 20kW to 48kW and there is room for more but my main fuse at 250A is the limiting factor. 
At this time the tyres 'screem' when pulling out every corner which is rather funny.
Topspeed was originally set to 90km/h and is now around 150ish.. 

Next step is lowering the suspension a bit and changing brakes to a ventilated setup at the front and disks at the rear from a Peugeot 106 GTI.


----------



## tylerwatts (Feb 9, 2012)

This little project is crazy fun! It must be like a gokart. I'd be scared doing 150kph in it though. How strong and precise is the suspension and steering? Do you have a photo of the underside of the car and where everything fits for interest please?


----------



## prensel (Feb 21, 2010)

tylerwatts said:


> How strong and precise is the suspension and steering? Do you have a photo of the underside of the car and where everything fits for interest please?


I have tucked two Brusa NLG511 chargers at the front where the original ConstantPower charger was. The rest is kept original.
The Zeva BMS is in the batterybox at the front. Modified the original batterybox loom so its just a plug-n-play install to the cars connectors.











The Think has standard Peugeot 106/Citroen Saxo front end rear suspension bolted to the chassis. So using the upgraded suspension parts from the GTI/VTS versions of these cars should be good enough. The Peugeot 106GTI has 87kW and max speed of 205kmh and about the same weight.


----------



## Duncan (Dec 8, 2008)

Hi
With a light weight powerful machine don't worry too much about the fuses

If the fuse can withstand 250 amps for an hour then it will take 500 amps for a few seconds - and during those few seconds you will have to lift off!

I'm running a Chevy Volt fuse - 350 amps - but my controller is set to 1200 amps


----------



## prensel (Feb 21, 2010)

Duncan said:


> Hi
> If the fuse can withstand 250 amps for an hour then it will take 500 amps for a few seconds - and during those few seconds you will have to lift off!
> I'm running a Chevy Volt fuse - 350 amps - but my controller is set to 1200 amps


Okay thats good to hear. The Simotion inverter is according the specs capable of 282Amps so i guess thats the max it will draw regardless of any higher (if even possible) settings. At my setup with 192V it would be about 54kW which should be ok 

I've looked through all settings in the inverters software and not all are clear to me for what they are or do. The one that i'm looking for is the 'ramp', like how fast does the current rise from 0A to 282A when accelerating. That should allow me to do some burnouts...


----------



## tylerwatts (Feb 9, 2012)

That sounds pretty good using all OEM suspension design then. This sounds like a great little car!


----------



## brian_ (Feb 7, 2017)

What I know about this car all comes from online research; however, the same platform appears to be used by not only by the Peugeot 106 (plus Citroën Saxo), but also by the larger - and heavier - Peugeot 205. There was even a Peugeot 106 Electrique. Perhaps one of the heavier variants might be a good source of some suspension components... maybe a 205 GTI. It might be worthwhile to check curb weight specs.


----------



## prensel (Feb 21, 2010)

brian_ said:


> There was even a Peugeot 106 Electrique. Perhaps one of the heavier variants might be a good source of some suspension components... maybe a 205 GTI. It might be worthwhile to check curb weight specs.


I know, i also have one of the Peugeot 106 Electrique models myself 
A lot of Peugeot suspension parts from the models 106/205/306 are very interchangable.


----------



## brian_ (Feb 7, 2017)

prensel said:


> I know, i also have one of the Peugeot 106 Electrique models myself
> A lot of Peugeot suspension parts from the models 106/205/306 are very interchangable.


How do the weight and front-to-rear weight distribution of the 106 Electrique and upgraded Think compare to the conventional models?


----------



## prensel (Feb 21, 2010)

brian_ said:


> How do the weight and front-to-rear weight distribution of the 106 Electrique and upgraded Think compare to the conventional models?



The Peugeot 106 GTI has a curb weight of 925kg.


My Leaf converted Think has a curb weight of 915kg with a 58% - 42% front-back distribution.


----------



## brian_ (Feb 7, 2017)

prensel said:


> The Peugeot 106 GTI has a curb weight of 925kg.
> 
> 
> My Leaf converted Think has a curb weight of 915kg with a 58% - 42% front-back distribution.


Excellent 
The Think body must be really light - EV versions (even with lithium batteries) are typically substantially heavier than the gasoline engine versions of the same vehicle. The front weight bias is interesting, too - the relatively light half Leaf battery is presumably the key to that, as well as the central (rather than rear-biased like most EVs) pack location.


----------



## prensel (Feb 21, 2010)

Did some 'long-range' testing yesterday, had a 120km trip on the highway, centre lane, overtaking and pushing the speed limit, only used about 65% of the packs capacity. So with some more decent driving I assume a 200km range would be possible. I'm happy about that.

The only annoying 'problem' now is that my pre-charge is playing up. On the initial key-start/sequence (key off-key on) it triggers an error in my Simotion controller saying pre-charge > 3 seconds.
After a second key sequence the error is gone so something must be adjusted to the pre-charge to behave well within 3 seconds. Not sure yet what is causing the problem..

Looking at the pre-charge circuit/schematic it appears as a MOSfet driving 4 PTC's in parallel. Each PTC is 120R so in total its 30R. The MOSfet is capable of 200V/3.5A.
My pack voltage is 196V => 196V/30R is 6.5A. more the the MOSfet could handle..
So whats is causing the problem: the MOSfet locking up on the first pre-charge and working on the second ?
OR are the PTC's playing up on limiting any current on the first pre-charge and allowing current to flow on the second go ?

Doing some math: 
Original pack voltage is 114V. 
My pack voltage 196V. 
Max current in the pre-charge circuit: 3.5A. 
So i need to 'waste' 196V-114V over 3.5A => 24R, P = 287W.
By adding a beefy resistor in series with the pre-charge PTC's it should work, in theory 

I need to find an easy way to measure the process without taking everything out of the car...


----------



## tylerwatts (Feb 9, 2012)

That is excellent success Prensel. Very nice upgrade and a great donor it seems.


----------



## prensel (Feb 21, 2010)

tylerwatts said:


> That is excellent success Prensel. Very nice upgrade and a great donor it seems.


Yes it is, although the car looks oddy to some people and I might look like a moron driving it it still lots of fun and to learn about EV's 

Yesterday I faced the problem of a public charging point kicking me off every ten minutes after charging start and with just 30% left of charge wasnt very relaxed. 

After a while i figured that my car and the other car on the same charging point where both requesting 3.6kW each where the point itself was just capable of delivering 3.6kW in TOTAL... okay time for an extra switch inside the car to limit or adjust the requested power, or just wire the CP signal from my Brusa charger to the plug...

But with two Brusa chargers installed I wonder how the CP wiring should work and how the charging point reacts to that...?


----------



## prensel (Feb 21, 2010)

Well it's been almost a year since my last post in this thread so time for a little update:


In the past 11 months I have driven over 11.000km with great fun and success. In fact I use it a lot as my daily driver to work, about 120km one-way.

Doing a quick recharge at the worklocation with the twin Brusa chargers at 6kW works good. Although sometimes the EVSE kicks me off for not respecting its lower output  The Brusa's currently work on a fixed profile but will soon be changed to CANbus control. Unfortunally a few weeks ago one of the Brusa's (bulk) stopped working and generates an error on some out of range voltage. The main/second Brusa charger still works and I managed to buy another charger of the same type and model for easy replacement.


I have thought about replacing the Brusa's for a modified Tesla Gen2 charger but because i'm working on/under the 200V limit and the Tesla is not the perfect setup for that so I'll keep the Brusa's in this project. When the defective Brusa is repaired (if possible) I will add it as the third charger so I can charge at 3-fase/10kW.



During the winter time I hardly could make it for 120km with the heater on and had to hold back on the 'throttle'. But since the temparature is rising it is clearly noticable that the former range is getting back.



Although the Leaf pack is said as being 24kWh but in reality it is lower. I'm using the Zeva BMS system and had to adjust the Ah setting back to 110Ah (I have two 60Ah cells in parallel, so it should be 120Ah) to reflect the real usage/capacity. I'm currently recharging until 4.12V (198V for 48S)
but i'm not sure if this will cause the drop of 5Ah per cell.


Next project is install of a full Leaf pack at 96S/384V in the new model Think City A306 as drop-in replacement for the defective Zebra battery.


----------



## perbandsholm (Nov 14, 2020)

Hi, I have a A306 from 2008 with a 'dead' Zebra battery pack. What will it cost for getting it updated to this solution here ?

Sendt fra min Lenovo TB3-X70L med Tapatalk


----------



## schelle63 (Jan 3, 2018)

Hi Prensel,
it is very interesting to know someone else is driving and modifying a Th!nk A266 model. My converted MINI has a former Th!nk's Siemens drivetrain. Which SIADIS version are you running?
Did you solve the issues concerning precharge/PTCs, and find the right parameters (ramp)?
150km/h! WOW! My controller is set to 10,000rpm, which gives me 105 km/h (ok., 10"-wheels are somewhat smaller), so I guess you have set the rpm limit above the 12000/min, which is Siemens' absolutely max. rated speed, or even higher (!)? How does the motor "survive" that? Or did you change gear ratio(s) to keep motor rpm down? How about the transmission? My drivetrain has more than 133000km right now, and I can hear the gears "whine" pretty loud. I would like to find new gears (with modified ratio to reduce motor speed).
I guess you already have all documents, but in case you need Siemens and Siadis manuals, I could provide these.
Markus


----------



## alfonatr (10 mo ago)

Hola.
Busco información, para saber si su controlador SimpBMS es compatible con el vehículo Think city A306 .
Recientemente compré una Think City con batería Zebra con errores ISO, y planeo instalar la batería Leaf, con SimpBMS.
¿Es compatible con la comunicación CAN del Think city?
He visto que venden su mando en diferentes webs.
www.secondlife-evbatteries.com/products/simp-bms

Lo siento por mi inglés, uso el traductor de Google.

Gracias


----------



## schelle63 (Jan 3, 2018)

Hi Alfonatr, last response from Prensel was April2019, unfortunately. 
The poor information I can provide to You ist that the A306 and the older A266 models drivetrain/battery/control systems don't share any single part. You may find useful info and help here:








Think City


Hast du technische Probleme mit dem Think City oder möchtest dich mit anderen Think Fahrern austauschen? Bei uns findest du eine Fülle an Informationen zu den Fahrzeugen des Herstellers Think Global AS. Abonniere dieses Forum (Schaltfläche 'Inhalt folgen') und erhalte eine Benachrichtigung wenn...




www.elektroauto.community





I take the chance to address again to Prensel: after 45.000 km, I am still having the same issues with my Th!nk-drivetrain: loud gears and precharge error message (3seconds...).
I guess when it starts charging the capacitors, MOSfet and resistors do not allow to reach the new voltage within the 3 seconds; but when immediately (!) re-starting (with the capacitors still partially loaded from previous attempt), the additional 3 seconds allow to charge to the required voltage.
I already had to replace some of the mentioned MOSfet, as well as some of the PTCs. It seems to me that this precharge circuit is not really capable to handle the higher voltage. There is even some place on the circuit board to add PTCs in order to reduce resistance and allow higher amperage during precharge, but I fear this could kill the MOSfet and/or the board itself.
Did You solve this issue?
Regards,
Markus


----------

