Nissan Leaf 2018 – Can you make your own Thermal Management System with 2 USB fans & a USB battery?

Nissan Leaf 2018 – Try to cool the battery down with 2 USB desktop fans and a portable battery by blowing air down the battery maintenance hatch. bad idea or genius plan? Also, talk about the “Eco Bar” and how to use it to your advantage when trying to keeping the battery cool.

USB Fans:

Ankey Battery Pack (older model in the video):

Channels mentioned:
Plug Life Television
e-NV200 Adventures
James and Kate
James Cooke
Electrified Journeys Japan

As a few people have asked and it seems right to share with everyone the charging sheet I’ve been using is located here:

Google Drive:


*Disclaimer all information in this sheet is a guide for long journey’s in the Nissan Leaf 40kWh to help maintain and keep the temperature down. Any adverse effect or issues with your journey is the responsibility of the driver and in no way entitled to any refund or court proceedings with this free information. Have a safe journey and do let me know if this actually helped or if I just got lucky 🙂

OBD2 Dongle:
LELink OBD2 (Leaf Spy Approved):
Car OBD2 Extension Cable:
Vgate iCar 2 WiFi OBD2 Scanner:

Camera Gear:
Canon M6
Canon EF-M 11-22 mm f/4-5.6 IS STM Lens:
Phot-R Flash Flashgun Arm:
Rode VideoMicro Compact On-Camera Microphone:
Vanguard Alta Pro 2+ 263CT Carbon:
Vanguard Alta PH-32 3-Way Pan Head:
Neewer Crane 3-Axis Handheld Gimbal Stabilizer:

Dash Cam used:
APEMAN Dual In Car Dash Cam Camera WQHD 2K 1440P:
Samsung 128 GB 100 MB/s Class 10 U3 Memory:

Artist: The 126ers
Track: Summer Love
Genre: Pop | Calm

36 Replies to “Nissan Leaf 2018 – Can you make your own Thermal Management System with 2 USB fans & a USB battery?”

  1. Jason Alexander

    The method you used did not make a difference in the temperature of the battery. The battery is sealed with the exception of a few small ports for airflow while the car is driving. The battery disconnect area is no where near these ports, and even if it was, air is not going into those ports without positive pressure. This will never be achieved because there are gaps around the battery that allow air to escape. Air must be forced into the battery through a dedicated sealed port connected to a fan and exhausted to make any kind of difference.

  2. Nicolas Raimo

    here's an idea for battery cooling, drive threw a large puddle or for a video drive hard and use a hosepipe on the underside of pack Like one of my subscribers did on his zoe when his aircon leaked so the coooling didn't work

  3. Albert Klappenberger

    I have opened the two battery access covers as you did. I am not using fans but sticking my hand in the hole while driving clearly shows the car fan is moving air over the outside of the battery. Without the fan there is no air moving even with the car traveling. I need to continue this but it seems to be having very little effect. I suspect nothing we do to the OUTside of the battery is going to cool it. The cooling must be INside the battery as with the Chevy Bolt and Teslas. I think the only cure for all this is to trade the car in on the next generation!

  4. Arnis

    There is no difference. I tried with cold water at home, and that worked. 5 minutes of spraying cold water and temp dropped from 41 down to 36 on average in 15 minutes. Why this method hardly works is that air doesn't conduct well and AC'd air is counteracted with warmed air from the front AC condenser.
    To have air blowing over the battery, switch on AC (so external fans turn on) but minimize load (turn it to warm and minimum fan speed). There is ~1m/s airflow over the battery when external fans are on.

  5. CrazyDaveVRT

    Great video James, always great to hear about your latest scheme to cool down a Leaf 2.0 battery.

    Pretty sure we can chalk up the results of this test to ‘measurement error’, the results are well and truly in the uncertainty band for the system. The battery pack is such a large thermal mass that the cooling system would need to be massive and integral to make a difference.

    What about liquid nitrogen through the inspection port?

  6. Aaron Williams

    I have always wondered what that Cyan Eco bar was for. I tried finding a description of it in the owners manual but couldn't find anything about it. I did notice that it moves around a little bit. How does it work?

  7. Pascal Lardellier

    avez vous pensé a diffuser de l'eau vaporisé autour du bloc batterie pour un meilleur échange thermique avec l'air ambiant?

    have you thought of diffusing water spray around the battery pack for better heat exchange with the ambient air?

  8. Ignac Trenansky

    peltier modules attached to the battery box (from ground) must be more effective… BUT …..The question is about if these baterries are ready for active cooling… And what about waranty of the battery 🙂 ?

  9. David Jones

    the real question is the outside temp the same? that is needed to show that the fans are even doing anything at all cause if the outside temp is slightly cooler that could be making the difference on battery thermals


    I'd have to say no you can't. Nissan should smarten up and make a real battery thermal management system like all the other big manufacturers are doing. They seem serious but yet don't grasp the concept of people wanting their batteries to last a long time. Or being able to quick charge more than once on a trip. Mind boggling.

  11. Iain Ansell

    not sure if the batteries have a heatsink which dissipate heat into the air, but if they do, you could attach additional heatsinks for better heat dissipation… this would probably have the opposite effect in the winter though…

  12. Peter N Bernfeld

    I have the solution. As soon as I can, if Nissan financing agree, I'm going to swop my 40KWh in for the 60KWh (if that's what it's going to be). With the Kona now available to order, Nissan are going to have to be pretty quick-smart in releasing the upgraded Leaf. And if the price of the Kona is around £30K (not sure if that's after the £4.5K UK government grant) then Nissan really do have a problem lol.

  13. Ybe EV

    LOL! Nice try James. Maybe the batteries closest to the fans cooled by a fraction of a degree. Get that "LEAF" blower, hahahaha! I think if it was that easy Nissan would have added some cooling. They knew it would be a challenge for their customers but cost of cooling for their current battery systems was probably not worth the investment knowing the LG Chem solution was in the pipeline. My 40kWH LEAF is doing great and for me its still the best car I have owned in 34 years. I have another long trip in September up to Fort William and really looking forward to the journey. I will follow your plan for longer trips as this was successful for me previously.

    Keep up the good work.

  14. Hye L

    How many watts do the fans have? Can you let the fans running for 2-3 hours after driving with battery over 40°C and with the rear windows a little down and compare it to just parking.

  15. Benjamin Reich

    Would you consider adding a video regarding how to open the access port? Also, if you believe based on the noise that the pack is not sealed within a complete shell, then I would second Joe McMorrow's comment. Reversing the airflow into the cabin might have more impact on battery cooling, by drawing a greater air volume across the pack.

  16. Andy Hiscock

    e-NV200 adventures is great – thanks for sharing.

    I've always thought the batteries were a sealed box within a sealed box, double wrapped if you know what I mean. I was thinking if some sort of large Petier chip thermally secured to the bottom or sides may help cool the battery box, a large one so its even cooling across the battery box (no cold spots) and low power one so its only sapping 5 or 10 degrees, not sure on the power, maybe whilst its charging only – using the chademo?

    Have no idea of the mechanics or feasibility but just an idea 😉

  17. Ian Mathieson

    Hi James, well done for spending the time to evaluate a concept. However, I don’t see any evidence that the USB fans achieved anything – and effect is clearly very small and the results are swamped by the data ‘noise’ of changing ambient temperature, varying charge rates etc. Re ambient, don’t forget a drop of 2 decrees would result in a drop of 2 degrees in the battery temperature albeit with a lag as the ambient fell, due to the thermal mass of the battery which slows the cooling rate without changing the eventual end point temperature.

    Re other fan ideas, before designing any such system, I’d want to know more about the design of the battery pack. For example, is the outer casing sealed (in which case the air flow would only be cooling the outer case, not the cells themselves directly)? Is the outer case in good thermal contact with the cells? If not, cooling it alone would be largely ineffective. Are there channels between the cells and does external air already flow through these, in which case adding forced air to this would improve cooling? Etc. Etc. Quite a project in my opinion, and I suspect from poor responses I’ve had from Nissan UK on other matters, it would be very difficult to obtain the necessary info.

    But well done anyway.

  18. luis C

    You need a vent/extrac at least for 500/600 m3/h , but for extract all heat need 1800 m3/h if you like to going down in temp. I plan to make a experiment with a extractor from electric motor with 800 m3/h a 220v, I plan to put a little inverter in 12v battery, to convert 12 to 220v, and put the extractor rear of electric motor in the central tunnel, and turn on, only when charging. Sorry for my English, greetings from Spain.

  19. IMHO

    I didn’t hear you mention what position recirc was in, fresh air or recirc. In recirc it would be like having all doors and windows in your house closed except one, and putting a fan in that open doorway. Whatever air you blow out is just going to come back in. But in fresh air, it would be like having a way for air to enter, as in opening a door or window at opposite ends of the house, and adding a fan to assist the natural breeze.

    Obviously you shouldn’t need to take your car apart to keep the battery in limits. Either Nissan designed cabin air exits in the right place to cool the battery when the fan is on high in fresh air (recirc off) mode, or they didn’t. Adding fans in the wrong area may actually counter designed air flow.

    Bearing in mind that all you can do is to try to reduce the temperature lag between the cells and ambient temperature by affecting one of the intermediate temperature zones, which is that between the outside of the battery case and the inside of the compartment formed by the underside of the cabin and the aeroshield under the battery.

    If Nissan designed the HVAC vent system to affect the system, it would be by forcing air which is cooler than ambient air through the intermediate insulation, which would cut the inherent lag from 12 hours down to 3 hours, meaning most of its cooling would happen between charging. And when the car is parked the battery temperature should remain sort of stable with a 12 hour lag so that it doesn’t heat or cool too fast when the HVAC is off.

    I can’t believe all the Nissan engineers are gender studies majors, so I wonder what testing they did and what is the real design. Which testing showed them that the eNV200 needs active thermal management, but the Leaf doesn’t? We need to hear from the actual engineers, not these PR idiots who just regurgitate something they don’t really understand.

    So far the only official explanation is “We fixed the BMS”, but that is not the answer to the question of why Nissan didn’t use some active thermal management system. I’d like to hear from Nissan engineering team the real answer. But where are these guys hiding?

  20. Joe McMorrow

    It's great you are taking the time and effort to explore options to increase range, reduce charging times and then sharing your results with the rest of us! I can see what your thinking is and can I offer a suggestion – don't force air into the vent, rather draw it out into the cabin. If at all possible, maybe fabricating a cardboard template, make the fans as airtight as possible, so they only draw in air from the vent. Not sure what this vent is for but maybe crack a couple of windows so you are not gassed by petrol vapours 😉 But seriously – be cautious.

    Second, batteries generate heat from the reaction that occurs when discharging or charging. If you are doing both at the same time then this increases the heat build up. So, DON'T stress the batteries – like running the aircon compressor. Disable regen! Don't heat the batteries by charging on the go. As I understand the Leaf battery is passive, there may well be airflow but the ambient temperature will dictate what effect this has. if the outside temperature is 28 degrees C then the batteries will only really cool to this level regardless – though I fully accept this may be a gross simplification of battery thermal management!

    In summary, as I am sure you know, it's always a trade off between speed to target (charger) and time taken when you are there (charging) for passive battery pack vehicles. As well as exploring the "active vent" idea, maybe adopt a "landing sequence" for the charger – 5 miles out, slow from (say) 70mph to 50mph and disable regen. The cost in time is 1 minute 30 seconds to reduce speed in this way for 5 miles. Disable anything else that may draw power like aircon or heater. Then see if charging once the batteries are cooler reduces beyond your 90 second "cost" for easing up on the battery load….because if charging to the same percentage happens faster, anything over 90 seconds is the benefit and you can gauge if it is worth the effort or not!

  21. Ellis Toms

    Because the battery is almost certainly sealed, you would not be getting any actual air flow through the battery. At best, just pressurising it.
    What you need to do is fill a load of large holes in your battery pack. Just make sure you make sure the drill bit is pushed right in and wiggle it around inside the battery pack to make a bit more room inside for the air. Drill some of those pesky battery cells or a bit.

  22. Eric Claasen

    I like the idea. I am afraid it will not have a lot of effect since you are unable to create a proper airflow in the battery package. I do not have to nerve to open it up myself but when you have done it is there a possibility to slide in a hose to the far ends of the package? Blowing in cool air through that and allowing it to escape from the hatch might give a better effect.

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