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Bilmerker => Tidlige elbiler: Think => Think City "Classic" (2000 - 2002 mod) => Emne startet av: pexic på Tirsdag 03. November 2020, klokken 08:32

Tittel: Piv4 lithium conversion and some upgrades
Skrevet av: pexicTirsdag 03. November 2020, klokken 08:32
Hello friends!

Thanks to Catalin and Tiek now I have a new project : to convert my new (1999) think piv4 to enerdel lithium.

First of all I have replaced the lead-acid battery with a home-made Lifepo4 one using some old 10Ah chinesse cells.

I have removed the NiCd stuff (batteries and pipes), now the battery box is empty.
Since I also plan to add a webasto I've decided to use the hidden compartment (see pictures) so I start cutting 2 big holes behing the seats.
I will use these holes perform tests on lithium conversion in order to keep the battery box in his place since, at least for me, It's difficult to remove it every day.
So, using 36s lithium configuration I start testing:
-charging works but it have to be manually stopped at 144v
-I have power at the wheels - ok.
BUT  :D  abd here we have the "new" problem:
- All the time (either charge or "drive") I have a sequence of 3 relay clicks at every 7 seconds comming from the "contactors box" inside the battery tray.
If you have some advice I will really appreciate it, meanwhile I'll continue with the conversion.

And another little odd stuff from this morning : the back tail lamps are always on... yesterday I did not have this ...

Regards
Viorel  [ You are not allowed to view attachments ]    [ You are not allowed to view attachments ]    [ You are not allowed to view attachments ]    [ You are not allowed to view attachments ]    [ You are not allowed to view attachments ]    [ You are not allowed to view attachments ]    [ You are not allowed to view attachments ]    [ You are not allowed to view attachments ]  
Tittel: Sv: Piv4 lithium conversion and some upgrades
Skrevet av: CasparTirsdag 03. November 2020, klokken 08:55
Hi, Nice with some more Piv4 conversion.  :+1: Are you running no BMS, and the original charger?
Tittel: Sv: Piv4 lithium conversion and some upgrades
Skrevet av: pexicTirsdag 03. November 2020, klokken 09:32
Hi Caspar, I have to keep the original charger for now, at least for the tests, in the future will be replaced and also I'll have a DC plug for direct solar panels charging.
No BMS during tests also, I don't want to start more mini-tasks in parallel, BMS will be my last concern, the cells are very well balanced for now.
I need to fix the non-stop relays clicks so I can move on  ;D
Tittel: Sv: Piv4 lithium conversion and some upgrades
Skrevet av: pexicTirsdag 03. November 2020, klokken 15:34
Ok, f*** the relays, I drove 3 meters, seems ok  :) now I'll go out on the street, if I'll not post here in the next 30 min. please cal 112! thanks.
Tittel: Sv: Piv4 lithium conversion and some upgrades
Skrevet av: pexicTirsdag 03. November 2020, klokken 15:49
All ok,  those -220kg and higher voltage (140v) make the difference  ;)
 I'll keep you all posted, have fun!
Tittel: Sv: Piv4 lithium conversion and some upgrades
Skrevet av: CasparOnsdag 04. November 2020, klokken 12:45
-220 kilo, have you done anything with the suspension?
Tittel: Sv: Piv4 lithium conversion and some upgrades
Skrevet av: pexicOnsdag 04. November 2020, klokken 13:47
-220kg now, during tests,  I only have 36s1p (35Ah), at thye end the battery box will be full (approx 20kwh)
Tittel: Sv: Piv4 lithium conversion and some upgrades
Skrevet av: pexicTorsdag 05. November 2020, klokken 08:45
Ok, so :
my car charge the battery to 161v  (normal charge)
my car will not start (system failure) if HV is over 151v.

I've had read all 51 pages of this sub-topic :)

In the light of these "new" data and to keep the conversion costs at minimum I've decided to go for 36s lithium configuration (3 x enerdel blocks).
This will help me a lot since the blocks are already assambled, they also have the plug for the future "active bms" and temp monitoring.

next step is to limit/stop the charging at 36x4=144v (max 4v/cell for long life), I think i can do this eitrher by:
-small device monitoring HV and at 144v this device will disconnect the "under the driver seat -service conntact" or
-the above device will change the original battery temp. sensor(s) value so the BMS will think that battery is too hot.
I'm open to other suggestions :)

Regarding the non-stop relay clicks I found a topic on this forum - no solution and also someone said this is "normal". Any ideas ?

Thanks in advance for your answers.
Tittel: Sv: Piv4 lithium conversion and some upgrades
Skrevet av: elektroluxFredag 06. November 2020, klokken 13:07
There is equipment to adjust the max starting voltage in Stavanger, Oslo, Cologne and Holland. No need to reduce number of cells.
Tittel: Sv: Piv4 lithium conversion and some upgrades
Skrevet av: pexicFredag 06. November 2020, klokken 15:34
Hi elektrolux , first of all I want to thank you for the contribution on this topic, I've learned alot from your posts.

All these locations are too far away from my Think (I live near Bucharest).
Also, I'm ok with how the car works at 140V, for the moment I will keep the car charger (aktia) and the car BMS.
For the charger to stop at 150V max only two possible solitions remains on the table:
-modify the temp senzor value (using a variable rezistor for testing purposes)
-disconnect the main plug (230v AC) when HV reach150v.
I've tested the solution with lid contactor under the drive seat and is not ok : the charger does not stop so unnecessary energy is lost.

Maybe I'll try to play with an old dos computer with old version of SIADIS but not very soon.

Next step is to test the max current (Amps) used in 36s configuration (thanks Nikolay for the nicometer software) in order to calculate what type of cable I'll use for enerdel modules connections.

Also by keeping 36s configuration the cost of aditional "active bms for enerdel cells" will be acceptable for my budget.

Regards
Viorel
Tittel: Sv: Piv4 lithium conversion and some upgrades
Skrevet av: pexicMandag 09. November 2020, klokken 13:43
Hi
new test results
flat drive, constant speed:
50km/h = 50A@125v
60km/h = 65A@120v
Tittel: Sv: Piv4 lithium conversion and some upgrades
Skrevet av: elektroluxTirsdag 10. November 2020, klokken 07:55
Check Ahr/km. Should be around 1 at this voltage.
Tittel: Sv: Piv4 lithium conversion and some upgrades
Skrevet av: pexicTirsdag 10. November 2020, klokken 11:36
Correct for 50km/h constant speed.  It will take 50Ah to drive 50km so 1Ah/Km ;)