Skrevet av Emne: Think City Enerdel Lithium Ion tråden  (Lest 1231 ganger)

BauDemo

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Sv: Think City Enerdel Lithium Ion tråden
« Svar #15 på: mandag 04. mars 2019, klokken 14:18 »
I think the pack is always balancing when it is "on".
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worry

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Sv: Think City Enerdel Lithium Ion tråden
« Svar #16 på: mandag 04. mars 2019, klokken 22:12 »
Thanks. That sounds reasonable.
Think lithium

BauDemo

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Sv: Think City Enerdel Lithium Ion tråden
« Svar #17 på: mandag 11. mars 2019, klokken 14:06 »
After experiencing power limit during the weekend (at 10% with min cell voltage around 2.80V) I wanted to add to my answer above that the balancing is done down to a particular cell voltage limit.
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worry

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Sv: Think City Enerdel Lithium Ion tråden
« Svar #18 på: mandag 13. mai 2019, klokken 22:08 »
Ikke mye nytt å fortelle her. Har hatt lite tid.
Men jeg har ryddet litt. Har kjørt omtrent 280 døde celler på dynga.

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pexic

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Sv: Think City Enerdel Lithium Ion tråden
« Svar #19 på: tirsdag 14. mai 2019, klokken 10:58 »
Hello Worry and all others (sorry for using different language)

What I have observed till now on the down side of RLEC boards:

-little smd transistors are used for balancing jos -> this means small balance current->this means long time (and energy) to proper balance the cells
-at the end of cell row (when these little transistors must work between 0 and 50v) the power dissipation is higher and transistors are getting hot, also they cannot lose the heat very quick do the "plastic like" glue that cover all the board.

IMO these RLEC board will not last in time.

What we can do about this:

1- the holy grail  (some guys on this forum have tried but not a final solution was posted yet) is to replace the MLEC board with some arduino or similar board and afterwards to use and independed BMS and any kind of cell types.

2-temporarely solution choosed by me : to keep RLEC only for CAN comunications and use an diffedrent and independednt BMS for Enerdel cells.

For 2 : we need to remove all defective components on RLEC boards and also the components that are responsable for shunting (balance) the cells
I'm working now to identify all these 12 transistors that are responsible for balance and remove them.
The new BMS will not be complicated neither expensive and will balance the cell with higher current (I aim for around 500mA). It will not be very accurate but it will do the job very well (I hope).
Also - this new BMS will have less and components so it should be fiable.

The work to be done will not be hard bit will be "alot" :) afterall we have to modify 16 RLEC boards...
The new BMS has to be done using same "like IDE HDD cable" as the actual RLEC and will be connected between battery module and RLEC board, this will save us work when we will change the MLEC boards and trow all RLEC boards in the recycle bin  :)

On my car I have other problems that I have to fix before start making the new BMSs  :(

have fun! 

worry

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Sv: Think City Enerdel Lithium Ion tråden
« Svar #20 på: tirsdag 14. mai 2019, klokken 12:06 »
Hi pexic,
Thank you for digging so deep into this problem. RLEC boards have been a problem since our batteries were new. The source of new boards have dried out, and repair seems to be the only solution. Or modification, as you suggest.  :+1:
I have just started to look into CAN bus and electronics, so basically I know nothing yet.  :o
Did you look into everything the RLEC do? The MLEC need data from RLEC to control charge and discharge, to show State Of Charge SOC, to control battery relays, limp home mode, temperature monitoring and so on. The RLEC manual lists lots of functions, but maybe all of those are not needed?
Keep up the good work, and please keep us posted. I read everything with interest, even if I don't understand.  :)

And please keep on writing in english. It's much better than google-norwegian.  ;)
« Siste redigering: tirsdag 14. mai 2019, klokken 12:41 av worry »
Think lithium

worry

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Sv: Think City Enerdel Lithium Ion tråden
« Svar #21 på: lørdag 25. mai 2019, klokken 23:35 »
Hei,
Progress! Vel, jeg har jukset. Har kjøpt en bil til, en som er i orden. Har gått 90tusen km og har aldri hatt batterifeil. I følge forrige eier går den 16 mil om sommeren og 12 om vinteren (webasto varme), hvis pen kjøring. Ladet den full i natt og tok diagnose på batteriet. Den viste cellespenning mellom 4.07 og 4,10. Ser bra ut.

Har ikke gitt opp prosjektene, men det blir pause. Naboen har renset de 8 RLEC-kortene med feil og byttet transistorer som så dårlige ut. Men ingen av dem ble i orden. Det neste blir å bytte alle transistorene på ett kort, for å se om det hjelper.

Jeg følger pexic med interesse. Men for meg er det veldig vanskelig å forstå detaljene.  :o
Det jeg nå ser som en mulig løsning er å tilpasse en custom BMS. F.eks. fra EMUS i Litauen. Men programmeringen får jeg ikke til selv. Foreløpig.. :-)
Think lithium