Delta - AC Mini Plus & EVNEX

Hey, I have one of the “Delta - AC Mini Plus (EVPE32xxxxx)” EV chargers that is listed on the supported page but I am having trouble getting it to connect to EVNEX. I’ve created the charger in the interface, loaded the config to the charger itself but it will never connect. The charger as far as I can tell has an active internet connection but is consistently showing the error “Backend system is not connected”.

Any tips or tricks on getting this charger to connect up?

Thanks for your help!


Hi Luke

Welcome to the Evnex forum!

This is the configuration that we use for the Delta AC Mini Plus:

OCPP Charge Box ID:[Your 4 character prexfix]-12345
OCPP Server URL:ws://
OCPP Security:2
Eth0 Network Mode:0
Authentication Mode:1
OCPP Offline Policy:0
Max Charging Time:0

Is this similar to what you’re doing? Note that the above settings are for an Ethernet connected network, so make sure you use Delta’s online configuration tool to set the charger up correctly for your application.

Please check:

  • You’re including the 4 character prefix for your account in the OCPP Charge Box ID
  • That you’re uploading your EVSEConfig file with no file extension, as in it should just be ‘EVSEConfig’, not 'EVSEConfig.txt"
  • If your charger is on older firmware, we’ve sometimes found that you need to add the server URL like this: ws:// (you could try this if the above steps don’t work).

Let us know how you get on.


Thanks Ed for your response - I just got the charger to come online… woohoo! :slight_smile:
Looks like it was the older firmware thing you mentioned as the only change I made to the config file was to add that “/ocpp” to the end of the URL.
Looks like my charger is running firmware v02.06.00.00… i’m guessing that is old and it needs an update?

Thanks again for your quick help!


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That’s great news. I think that’s a pretty recent version of firmware, so you should be ok. It might be that these chargers behave differently depending on the network interface they’re using. Our unit here is definitely happy on just ws:// without the /ocpp, but we’ll have a look into this at some stage.

Cool, thanks again for your help! :slight_smile:

Hi Luke

On closer inspection, you’re actually a few versions behind:
See changelog for the Delta AC Mini Plus below:

V02.0A.03.00 (Latest)
Added OCPP16 Reset command
Added OCPP16 string len detect

Using MPU to caculate energy used, because of the 1st FW and HW version issue.

Increased the download speed of log files, downloads should take 5 minutes or less via USB.
Added feauture [Auth] keep antena on for using RFID to stop charging

[Solution] Optimized OCPP 1.6 module
[Solution] Optimized communication between system and OCPP 1.6 module to fix meter value after power cycle

Optimized the Wi-Fi module reset algorithm

If you want to update, firmware files are available from Delta here:

Though you’ll generally need to use Firefox to open this, or an FTP Client like FileZilla.

Aside from that, if your charger is working ok, there’s probably no mad rush to go and update it.


Ahhhh awesome, thanks for that. I’ve updated it now to the latest v02.0A.03.00 and it now works correctly without “/ocpp” needing to be on the end of the URL. Thanks again for your help Ed! :slight_smile:

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