Planing CanView and BMS+ conversion with lithium

the cells have arived!! ( the first one i got out is 3,23 volts ) tonight i wil try to measure and unpack al of them

al cells seam to be inside a fulle sealed anti static foil.

i removed some numbers and serials just because i also see people doing that on other forums
not sure wy?

 

here a few picture about the shape of some cells
not that great! but placing it on a table and pressing on it makes them nice and flat
also a few have small puctures in the outer foil but nothing to bad or going tru it.

did any of you have the same?

edit: all cells unpacked. 3,18-3,22 volts most are 3,20
some or wel all of them have little dents in them.( look at pics ) only few are really perfect
some have A1 or A2 or nothing like that in printed in the middle of the celss
some have a red marker stripe on the left corner
only a few are a little bent look at the pics

what did your cells look like? same?

edit:
add a picture of a guy that did a A123 20ah cell test from full to 2,0volts and got up to 19,x ah
but when you look at 3,0 it starts to fall.. and because i want to stop at 3.0 discharge i will have to expect ~13,8ah instead of the 16ah that i expected at 80% dod.... thats a hit on capacity if this is really the case.

the a123 sheets tels us 3.8 max and 1.6"??" lowist cel voltage
http://www.a123systems.com/Collateral/Documents/English-US/A123 Systems AMP20 Data Sheet.pdf

 

Flying

What is bad for A123 cells is when there is some gas inside and then when they are not flat.
They can be a little bend during transport.
The enveloppe is not hard and even small pieces of polystyrene can make little dents.

Charge them (3.2v is discharge) and test them.

I can use mine up to 18.5 Ah with 210V bms+ end voltage in summer.
The lower cell having this range: 3.54v - 2.8v
The average beeing 3.54v - 3v

After end of trip, cell voltage goes up to 3.1 3.2 volts

 

i do see some things that are not from the outside but inside
look at picture you see bubbles

 

Mr plugin.

Canview display only 6,57 Ah.

I don't understand how it is possible, because your trip was 32 miles long ?

6,57Ah*230v=1511 Wh so only 29,5 Wh/km. I never saw less then 82 Wh/km in summer !

So i would guess more then 20Ah. Also because your cellLog have beeped.

 

I have 10 CellLog8S and three of them get a blank white screen now and then and I have to replug them to get the screen back. It must be a common problem with the 8S model.

 

nice i cant wait to drive my setup

so you only have 1 celllog that with the usb for logging? and the other cells are the ones wihtout ubs and no loggin?
wy did you do that? to keep the cost down?
i geuss the temp readings are al in F or C?
when you cell log 8s locksup does it still measure or reallys stops working?

 

Thank you.

Just for you, after crossing atlantic ocean, this become 150 Wh/km and 51km. 50F is 10°C

Canview receive info from can bus. So we use exactly the same data.
Amperage came from hall sensor and voltage is the same for nimh and lithium.

I forget asking you the cellLog end-voltage you used.

 

i got good news
the elcon 1500 PFC charger got a analog voltage input where you can set between 2 and 5 volts where 2 volts is 0% current and 5 volts is 100%
so you can use a potentio meter to control your amps out of this charger or use a switch with risistor to set a fixed amps

this way i can use the reletive cheap bleeding boards that bleed at 300mAmps and do a topoff balance charge ones a week or when ever needed when the cell logs tell me the balance is starting to grow.
on the other moments i just use the max amps to charge the cells to where the cell logs wil trip the relay and shutoff the charger.

only problem that i see now is these bleeding board for lifepo4 have a 200mA at 3,8 and 300mA at 3,9..... 3,8? 3,9? thats to high...

so when i stay at 200mA charge current ( thats about 4% of 5 amps ) the cells will al charge up to 3,8 volts.. thats max of what they are suposed to handle

or can we safely say 3,8 is still ok as long it not 4 volts

yesterday evening i also charged up 1 cell to 3,6 the next morning i read 3,49 volts
i putt in about 7ah and i used a small RC lifepo4 charger at 5amps charge current CV CC
i did not look at the temparture but i did touch the cell with my hand and at the end if charge its still the same temp.. did not heat up at all.

 

lopezjm2001 do you know if this is only a problem with the USB 8S versions or also with the 8M version?

edit : zenerdiode for cel balancing
http://thebrightsideforums.com/viewtopic.php?f=15&t=18
masybe this also works for the bugger cels when the charger can be set to a low amps setting?
o do these things keep running of energy from the cells when not charging.

 

ok I did read about it and what to do I just wonder if its also needed for the 8m


what do these cellogs use when not charging? mAmps

 

Bms data

To day I drive 38km and it was the first day with zero error on the data send by my bms.eace:

This week I solve the main problem : differential voltage between the bluetooth and the bms. When amperage on HV side was over a thresold I received bad data. The bluetooth must float with the lithium cells.

And Yesterday found the second and last problem: a bad welding on a connector that give bad data randomly.

Here is the 38km (23.8 miles) trip.
Voltage given by the bms. Lowest cell end voltage was 2,8v
Amperage betwwen -110A and +70A.
During regen voltage can goes a little over 240v.

 

nice:rockon:
can you also tell us what your fuel use was? zero to? ;-)
kwh etcetare

 

ok 0,04 amps at ~3,5 volts? x 70 = 9,8 watt per hour for the 9 cell logs
mmm i think thats a lot dont you? standing stil for 1 day and you lose more then 230watts = 1km less range
1 week and you lose 7 km.
i read that you can disconnect the 1 pin that way the unit wil not shutdown but use far less