Nissan LEAF battery
Here are some frequently asked questions and good info on the LEAF batteries
- The following info is valid for both LEAF and e-NV200
- Remember to seat the service disconnect switch. Without this fitted, the battery will not output any voltage when contactors are closed.
- If you are using the 2011-2012 24kWh battery, you can enable INTERLOCK_REQUIRED in the software for extra safety.
- LEAF battery specific limits are found in the "USER_SETTINGS.h" file
- The default %-limits for battery charging 800(80%) and discharging 200(20%) is excellent for maximizing battery life.
- Do not set the battery MAXPERCENTAGE over 990(99.0%). If you do you will have no high SOC% shutdown protection (but you will still have current stop request)
- On a similar note, it is not recommended to set MINPERCENTAGE under 50(5.0%), the LEAF BMS sometimes treats the battery as absolutely empty at this percentage level.
The battery packs (24/30/40kWh) are all the same physical size. The 62kWh battery however is 40mm taller.
- 24kWh = 277kg (601pounds) 1547.0 (L) × 1188.0 (W) × 264.0 (H)
- 30kWh = 294kg (648pounds) 1547.0 (L) × 1188.0 (W) × 264.0 (H)
- 40kWh = 303kg (668pounds) 1547.0 (L) × 1188.0 (W) × 264.0 (H)
- 62kWh = 410kg (903pounds) 1547.0 (L) × 1188.0 (W) × 304.0 (H)
The following pictures show an example of hooking up a LEAF battery to a Fronius Gen24 inverter.
Here's how to wire up the communication between the components.
Here's how to connect the high voltage lines
Here's how to wire up battery low voltage wiring
An even more detailed connection diagram, with automatic contactor control via solid state relays for maximum safety:
Almost all EV batteries contain contactors and precharge relays. Contactors act like big relays, and are used to control electrical circuits where currents are high. They are designed to be able to break the flow of current in a safe manner without electrical arcing. There are two contactors, one for positive and one for negative. To avoid electrical arcing when turning on the battery, the initial inrush of current is led thru a precharge resistor, to allow for slow charging of the capacitors inside the inverter. If the inverter has been turned off for a long time, the capacitors inside will act almost as a dead-short, 0 ohm resistance. If you skip using the precharge, then your contactors will spark every time you close them, wearing them out prematurely. Now that we know what the contactors/precharge does, we can look at ways to control it.
The Nissan LEAF battery can be used in two ways. Manual and automatic startup/shutdown of the contactors/precharge circuit.
Using switches and manual timing, it is possible to turn on the precharge(A), negative contactor(B), and positive contactor(C). This is the simplest method, but it increases the risk of failures. Accidentally flipping the wrong switch at the wrong time may damage the battery and/or inverter. Also if you leave your battery un-attended, the battery has no way of disconnecting from the inverter incase it senses a fault. Due to all this, the manual control method is NOT recommended. Here is a link to a picture describing the wiring, and startup timing requirements: https://github.com/dalathegreat/BYD-Battery-Emulator-For-Gen24/blob/main/Images/BatteryControlWiring.png
The LilyGo hardware can act on its own, and turn on/off the contactors/precharge resistor when the battery says it is OK and turn off when not OK to proceed. This is done via the 3.3V digital output header that is located on the board. To use these, you need to solder a 2x6 row connector onto the board. After the row connector is fitted, you can connect a flat ribbon cable between the pins, and the relays.
For instance, 3x ASR-10DD can be used.
To enable the feature in the software, uncomment the following line in the USER_SETTINGS.h file
#define CONTACTOR_CONTROL //Enable this line to have pins 25,32,33 handle automatic precharge/contactor+/contactor- closing sequence
To keep things simple, it is recommended to use Solid State Relays (SSR). These can be activated with 3Volt, and control large DC currents. Follow this schematic to complete the circuit:
- (LilyGo) Precharge pin 25 - Precharge SSR + input
- (LilyGo) Positive Contactor pin 32 - Positive SSR + input
- (LilyGo) Negative Contactor pin 33 - Negative SSR + input
- (LilyGo) GND - All 3x SSR - input
Before the contactors turn on, both Inverter and Battery needs to give OK ✅ signal. This can be verified via the Webinterface:
NOTE: with some Leaf BMS (so far only noticed on the 30kWh 2016) the line batteryAllowsContactorClosing = true is never set: https://github.com/dalathegreat/Battery-Emulator/blob/main/Software/src/battery/NISSAN-LEAF-BATTERY.cpp#L452 . This prevents the automatic contactor sequence. A workaround is to force the value to always true. So if you are having problems with the contactor sequence, change the batteryAllowsContactorClosing = false -> true in the NISSAN-LEAF-BATTERY.cpp file!
Incase your battery is missing some wires/disconnect switches, here are the OEM part numbers and purchase links. Do note that it might be cheaper to source from your local scrapyard!
| Product | Purchase Link |
|---|---|
| Service disconnect switch (2011-2012) 2971C13NA0B | Ebay |
| Service disconnect switch (2013-2023) 297C1-3NF0A | Ebay |
| 22pin battery connector (2011-2012) Yazaki 7283-8750-30 | AliExpress |
| 36pin battery connector (2013-2023) Yazaki 7287-1065-30 | AliExpress |
| Precrimped 22/36 connectors | AliExpress |
| High voltage connector 80kW 297A6-5SH1A | Ebay |
| High voltage connector 6kW PTC 297A6 3NA0A |
|
22 or 36pin connector are designed with an hole of 2.1mm that would contain cable and included elastic ring for water proof seal. AWG 22 (0.5mm2) is enough cable section for the supported Amps.
Normal cable of the above section (22AWG) have a protective rubber that is too thick (usually 2.1mm external diameter) => need to choose automotive cable that follow reduced rubber cable standard (FLRY-A or B ISO 6722) that shouldn't be thicker than 1.5/1.7mm (better 1.5) outside diameter.
Need at least 0.7/1mm thick cable (e.g. cable + wrap) to allow correct water proof e.g. no ethernet cable can be used because too thin. Eth cable can go from 23 to 26 AWG. Normal AWG is usually 24 AWG that is rated for max 0.5A. HV battery contactors drain continuously 0.4A each one at 12v.
BTW it's not strictly necessary to be automotive grade cable if it has enough copper diameter (0.5mm2) and outer diameter of ~1.5mm.
NOTE: If you pin your connector yourself - ensure the pins go all the way to the bottom and the pin is seated properly. If they are inserted incorrectly (not far enough, "wonky") then you won't have proper communication.
- FLRY-A Automotive low voltage cable (FL) with reduced thickness of insulation (R) made of PVC (Y), with regularly stranded conductor (A)
- FLRY-B Automotive low voltage cable (FL) with reduced thickness of insulation (R) made of PVC (Y), with irregularly stranded conductor (B)
Original part number for nissan leaf battery is 297A65SH1A but a cheaper alternative for battery HV connector can be found in scrapyards. Renault Zoe or Kangoo Batteries use the same connector as Leaf battery. 297A22581R is the part numbers for both car.
If you are mounting the battery indoors, you can also 3d-print a high voltage plug. This is generally not recommended, due to no IP rating, and no voltage rating. So try to source a real HV connector if possible! That said, this is a link to Pelle_C's excellent 3d-printable connector: https://gitlab.com/pelle8/3d
The 2013+ batteries have an external high voltage heater port. The port can be plugged with silicone, and for instance a 3d-printed blockoff: https://www.thingiverse.com/thing:6534111 (Credit to machining program at William M. Davies vocational school. Lincoln, RI USA)
The LEAF battery has some additional safety checks, that can cause the software to go into warning/error states. See the event view in the webserver to learn more about these!