OpenEnergyMonitor Community

Newbie stuff Open evse, Nissan Leaf

At this time of year I’ve got stacks of surplus solar. I already have a power wall & my car recently giving up has made me look at ev’s. Seriously considering an older leaf (hopefully 6.6kw charge. As they seem v good value.

Any advice / experience on open evse / leaf would be great. Would it all integrate ok with power wall?

I Graeme, I’ve been driving a Nissan Leaf with a 6.6kW charger for the past 6 years. It’s been great, and still going strong after 76,000 miles.

I use an OpenEVSE to divert excess solar PV to charge the car on sunny days. To use the solar PV divert function of the OpenEVSE you will need to have an OpenEnergyMonitor emonPi solar PV to monitor the solar PV generation and excess grid export. The OpenEVSE can divert the amount of excess energy (grid export) to the EV.

Thank you… I have an emon pi already so just need the openevse bit & an electrician to fit?
Assume the emonpi can be located in a different place to the openevse ok? the pi is next to the main consumer unit in the house and the evse would be in the garage.

Out of interest the adds for cars say stuff like “Just had its big service” - What does that mean for an EV… no cam belt etc…
Have you had any problems / unexpected costs at all with the leaf?

My Leaf30 is 4 years old and has only needed one repair – creaking wing mirrors, done under warranty.

Solar panels here are only 3.0kW and I couldn’t justify the extra cost of OpenEVSE since I already have a dumb chargepoint, paid for by OLEV. Instead, on sunny days I use the “granny” cable (2.0kW) with a £15 TP-Link WiFi plug, controlled by emonPi and node-red.

Ok so OpenEVSE installed and setup with emonpi/emoncms.

Not had any decent sunshine yet so the car needs charging tonight. If I select eco(pv divert) but also have a timer set 02:00 - 06:00 (for our cheap rate) will it still start charging in at 2am in the morning and stop at 6am as well as doing the pv divert during sunny hours?

From my experience, no. The two modes aren’t compatible.

Yes, that should work fine

What WiFi firmware version are you running? This issues should have been fixed a while back. The latest version is V4.1.0: Releases · OpenEVSE/ESP32_WiFi_V4.x · GitHub

I’m on v4.1.

I know the existence of the timed period was stopping the Eco divert and that is definitely fixed but I hadn’t realised that also meant I could leave it on Eco permanently and also get the timed overnight charge to kick in as programmed.

I’ll have to try that and if it works, then that’s how I’ll generally leave it set.

Yes, this should work. Let me know how you get on.

Great thanks for the responses.
I’m on Ethernet so assume WiFi comments not relevant.
Also I’ve been “using” the emonpi for 6 years or so and I’ve just started from scratch with it on a new SD card… massive improvements in ease of setup since I last had to do it. Well done all.

Update. The charger works 02:00-06:00 but unless I cancel (stop) those timings it won’t charge on solar excess.
As mentioned in connecting by Ethernet.

Ok so Ive read through the docs again and think I now understand a bit better that the wifi / ethernet thing is not just a dumb connection but integral to how openevse is controlled. & therefore it is relevant that I update it.

Updating… from a windows machine
So far following instructions I have choco, python, but all I get in installing esptools are errors in red text on a blue background… I’m not colour blind but who at microsoft thought that was a good idea!!!

So I need C++ v14 or higher… buildtools has an extensive menu of ‘stuff’ can anyone point me in the direction of what I need (minimal install).

Update - Stuck… help. How did others get esptool to work on windows…?

@glyn.hudson can you advise on the above. This is a new install via East Green Energy to get the grant but it has older firmware on it? as its Ethernet I cant use the web update so need to use esptool

this is an extract from the update doc. Make sure you download the pre-compiled version.

Uploading pre-compiled

Pre-compiled FW can be downloaded from the repo releases page, look for esp32-gateway-e.bin

ESP32-gateway can be connected by micro USB and firmware can be uploaded using esptool:

For rev G --before default_reset --after hard_reset write_flash 0x1000 bootloader.bin 0x8000 partitions.bin 0x10000 esp32-gateway-e.bin

For rev E

esptool --baud 921600 --before default_reset --after hard_reset write_flash -z --flash_mode dio --flash_freq 40m --flash_size detect 0x1000 bootloader.bin 0x8000 partitions.bin 0x10000 esp32-gateway-e.bin

direct link to the compiled file

Hope this helps


Thanks for the reply John.

I think from the instructions I’ve read I can’t use the web interface as I’m on the Ethernet version so I need to get esptool to work?

I didn’t read the instructions … but just upgraded my rev E gateway board from 3.x to 4.1.0 from the web interface so it might be worth a try. Maybe it’s once on 4.x that it no longer works?


Tempting to risk it but could break it & then I’m without charger. Also mine is a brand new setup from the shop, but frustratingly has 4.01

The Ethernet and WiFi only versions have the same functionality (other than the addition of Ethernet :wink: so you can update from the web UI no problems, just be sure to use the correct firmware

Hi thanks for your reply, your advice is contrary to the user guide which specifically states that the Ethernet version must update using esptool.

Can anyone clarify this is still true & if it’s not, why it the guide saying this?

Ah, I apologise, yes this is the case, HTTP upgrade does have a bug reported against it. I am looking at upgrade at the moment so will try to resolve this issue