Planing CanView and BMS+ conversion with lithium

That will be a time savings.................

 

My guestimate is around 500 pounds which is what my new raised coil springs are rated for which I will be installing in about 4 weeks time. Enginer quotes 300pounds for a 8kwh Enginer kit then add extra DC converter and charger and 4kwh A123 pack. Along as it raises the rear wheel arch to match the front wheel arch height.

 

Just so I am correct(understanding) in your setup.
hybrid bms plus (yes)
72 cells 40ah 3.2v
(charger)? brand/specs
(ev button) ?
cell boards or balancers (no)
cell logs (yes)

 

9 min of your time? better?

prius main relay replace "Speeded up" ( WARNING HIGH VOLTAGE DC WILL KILL YOU ) - YouTube







the A123 pouch defects are not that great for us i think
according to xueming these cell came from the usa plant
he told me in the past that cell where shipped from usa to china and then from there to me.
so the potential that i have 1 out of 4 cell of those defective cell that will not last that long are great.
maybe these are the rejected cell from that failed machine. ( 1 our of 4 machine seems to produce defective cells )
big bummer again....
just lets hope i can still drive a while with my car without mty battery pack braking down to fast ( cells no longer have any cap left ) or that i get a fire?!
according to A123 the defect did not cause any safety problems... but reverse pol on defective cell with diminish total pack capacity

 

OK

this weekend i start assembling one of or all 5 boxes.
i am thinking to go back to 70 cell instead of the 72
its not a big range hit and the cell oem and A123 will be more closely matched.
so i can keep them connected without cells going down to a to low voltage when driving
what is the case now with 72 cells

 

:focus:
Hey
I just want to thank you being OP(Mr Plug)
I like what you have done with your set up
give us another update when possible

 

Hello planétaire and all ,

I have bms+ and a CANview system but only one additional nimh pack. The maximum operating range is 17km in pure EV. Now I'm building five subpacks with 14 A123 20Ah Cells.
Thanks for the inspiration planétaire the idea with the five battery boxes is great.
Can you give me more details about the Peter Berkins bms (schematic, layout, etc.)

best regards
AustrianPrius

 

Austrian.

Glad to see how these 5 boxes are worldwide known

Perkins bms is very well documented for example in Battery Vehicle Society • View topic - 25 Cell Multi Slave Board

You have schematic, layout and hex file.

One of the problem you can have is that Peter and Greg have plenty of versions.

Their bms use a slave for each lithium cell and a master.
Each slave have a pic (12f683 2v-5.5v version) that read continuously the cell voltage on which it is connected.

How this bms work ?
The master send a pulse to the first slave. Then this slave send on a second bus, the "output bus" a byte containing the cell voltage. When finished this slave send a pulse to the second slave and so on.

So on the "output bus" you get all the cell voltage serialy. This bus is at 9600b/s inverted logic.

Actually, because I already used a Pc in my car I don't build the master board.
This pc talk with the slave bms. For 70 cells, half a second is needed.

Because nimh is floating relatively to the car body, it is very important that this "output bus" be isolated. You need a beter solution then the optocoplers used by this bms.

I use a bluetooth to ttl converter. And actually it is powered by his own lithium cells (very important).

Slave boards are connected to lithium cells. The wire used must be short if possible. If not increase his size. Or use 2 wires, one for measuring an the other for the shunt.

 

Thanks planétaire,
I will study the bms thread.

 

hey look
Toyota Prius (2nd Gen) High Voltage System Operation - YouTube

 

I have noticed the compression of the ICE like you guys talked about
but i have my battery pack not connected! i am driving in ORG mode with the bms+ connected with the OEM pack.
when i brake hard for a stop light that i missed the voltage goes up and the CCL goes down where the ice will spin because the prius does not allow lots of energy into the battery pack
i never got this when the bms+ was not connected.?!

strange..


EDIT:
jack from EVTV got several cells that shorted out on him
http://www.youtube.com/watch?v=3ssYq_Juj50&feature=player_detailpage#t=3534s

 

I saw this too during braking. When driving with bms+ and only the stock nimh. I think bms+ don't let voltage going over 245v, unlike the hsd that let it goes up to 270v or more.

Bms+ is designed for using a battery that have a smaller internal resistance then the stock one. I believe that bms+ don't know how many battery are connected and then use the most prudent action.

So, if only the stock nimh are connected, engine can come in compression mode during hard braking and/or long braking.

 

can it be that because SOC is based on voltage ( with the BMS+ ) and SOC will go up with a high voltage during braking it will lower the CCL? and with a high SOC will use the ICE to brake instead of on the E motor.?
so you think when driving with the litium pack this wil not happen? the voltage when braking will also go up so you wil have the same problem right?
i think for BMS+ and litium connected ( phev mode or is this only happening in org mode? ) this needs to change other wise there will be braking losses and more use and ware of the normal brake pads

 

When you connect the lithium, the internal resistance is very reduced. So voltage don't go high during braking.(Except if your lithium cells are fully charged)

Here the relationship between amperage and volt; in red with only nimh cells and in blue with both nimh and lithium. Same car, same trip.

 

yes when fully charged..
so it will happen when you drive off

 

Dear All,

I had the first big step: yesterday I got the 72pcs A123 cells.
But 12pcs of the is curved and 1 is too soft (I can fold it by my hand)
The most cells has 3,45V but all cells is between 3,38-3,5V it is good?
What do you offer to do them?

Thanks,
Europ

 

did you make a video about that soft cell? i did see one on youtube showing a "soft"cell so maybe that was you

i also have cells that where bent and when st8 out you can see some movement within the layers.
until today those worked but have no idear what the long run will do

did you get 72 to make a 70 cell battery? or 72 cell battery
then you have no spare's... always get a spare or 2.

 

The soft cells are usually a result of the cells losing their vacuum. If you can smell the electrolyte which smells like super glue then it is definitely punctured.

 

Great graph, thx for sharing!