Fixed my battery, got an article in the local paper :D

Last fall I bought a 2015 Leaf with an unknown to me battery issue. The car only managed 25km. I cracked open the battery, balanced the faulty cell, and now get 100+km of winter range
Here is the full buildthread in English for anyone interested: http://www.japtoys.net/forum/viewtopic.php?f=10&t=3613

I'm so excited, and in the process of figuring out how to open my own garage for servicing,replacing and upgrading Nissan Leaf's! If you are situated in Finland, out of battery warranty, I might be able to help

Congratulations! I seem to remember you posting about the car here. Is the weak cell still holding up OK?

Congrats Dala!

I noticed you said that the two cells said 30 on them. If they truly are 30 kWh cells, they do have a different discharge curve than the 24 kWh cells and absolutely should NOT be used with a 24 kWh BMS, let alone mixed.

The 30 kWh cells hit VLBW on a 24 kWh BMS at roughly 50% capacity remaining. They will then drive the second half of their capacity before hitting Turtle. The 24 kWh BMS may also slightly overcharge the 30 & 40 kWh cells, which won't be catastrophic but may shorten their life.

Given that you're having turtle and other issues, I suspect that the cells aren't actually 30 kWh cells, or if they are, they've been damaged.

Very exciting that you're considering opening a Leaf repair shop in Finland!

Lothsahn said:

The 30 kWh cells hit VLBW at roughly 50% capacity remaining. They will then drive the second half of their capacity before hitting Turtle.

Click to expand...

Really? This seems crazy unless there is something special about the discharge curve of the 30kWh cells. My battery will hit LBW at 14%. I've never had it below 9% but I can't imagine another 50% of use after VLBW. What am I missing?

goldbrick said:

Lothsahn said:

The 30 kWh cells hit VLBW at roughly 50% capacity remaining. They will then drive the second half of their capacity before hitting Turtle.

Click to expand...

Really? This seems crazy unless there is something special about the discharge curve of the 30kWh cells. My battery will hit LBW at 14%. I've never had it below 9% but I can't imagine another 50% of use after VLBW. What am I missing?

Click to expand...

Edited original post to clarify.

If you use a 24 kWh BMS with 24 kWh cells, no issues.
If you use a 30 kWh BMS with 30 kWh cells, no issues.

If you use a 24kWh BMS with 30 kWh cells, it will indicate VLBW when actual capacity is 50% or below. This is because the 24 kWh cells hold a higher voltage until they're almost empty. The 30 kWh cells have a more gradual voltage drop and a lower max voltage. Therefore the car thinks the battery is dead due to the voltage drop when, in reality, there is a lot of capacity left. This makes putting 30 kWh cells into a 24 kWh Leaf impractical.

If you haven't opened up your battery pack and swapped battery cells in your car, this doesn't apply to you. Your car's BMS would match the cells in the battery and your range indication would be accurate.

:mrgreen: :mrgreen: :mrgreen:

I thoroughly enjoyed your thread, and kudos !
Regarding charging, I thought that Finland has Shuco plugs on the roads that people use for ICE engine heating.

LeftieBiker said:

Congratulations! I seem to remember you posting about the car here. Is the weak cell still holding up OK?

Click to expand...

Yes, still holding, although limiting my max charge to 83% SOC according to Leafspy. I intend to swap in a better cell soon.

SageBrush said:

:mrgreen: :mrgreen: :mrgreen:

I thoroughly enjoyed your thread, and kudos !
Regarding charging, I thought that Finland has Shuco plugs on the roads that people use for ICE engine heating.

Click to expand...

Yes, Finland has heaps of schuko 240V readily available, so all homecharging is fast!

Dala said:

Yes, Finland has heaps of schuko 240V readily available, so all homecharging is fast!

Click to expand...

Yet it does not solve your LEAF charging problem. Why ?

SageBrush said:

Dala said:

Yes, Finland has heaps of schuko 240V readily available, so all homecharging is fast!

Click to expand...

Yet it does not solve your LEAF charging problem. Why ?

Click to expand...

Apartment dweller with no parking anywhere -.-