HV Battery Voltage fully charged and fully empty

[iainventor]

hi there am going to modify my car with older refurbished Tesla Battery pack 90 cells think full each cell 4.2 volts 378 volts

if I splice them into inverter hvdc is that too high of voltage to fill the 2 focus batteries in series , want to make a range-ex since can get the 5kw hour bricks for $1,200 each so 4 should get me possible 16.5kw hour usuable should get me another 60 miles.

So 1 thing also forgot have 2013 Ford Electric.

Anyone know what full voltage on Focus is and a safe charging voltage is and will the Tesla packs be too high at full charge at 378 volts and think charge and drive that might make a difference too on the top end voltage.

Any info would be great doing this as a summer project to charge and drive so I can get back and forth on my 82 mile commute and run AC so I do not sweat to death.

 

[triangles]

Where are you located? Sounds like an interesting project. You will have to do some reconfiguring, IIRC the focus battery has 88 cells. I think the nominal cell voltage is 3.7V and full pack charge is 360V or about 4.1V per cell. Google can probably help you verify these numbers. I am curious as to how you plan to implement this. I can't imagine a 90 cell pack spliced in with an 88 cell pack would work very well.

 

[iainventor]

triangles

I am in Eastern Iowa by Davenport, IA . Thanks for the info about 88 cells in Focus compared to 90 in Tesla. HVDC would probably give some wiggle room like +/- 10%. I know on the Focus Level 2 compensates input voltages like down to 100 VAC input per leg to like 160 VAC per leg on electricity for onboard battery charging.