D40 final outcome. What can it do?

I have had my D40 for about two weeks and during that time I had a few issues. With a recent firmware update, here is the final outcome of what it can and can’t do:

Powering with LOAD MODE (regulated 12 VDC output for connection to a device or fuse block) works well and has an absolute 20.7 amp maximum output. After 20.7 amps, the output will overload with a red indicator on the D40. Turn power off and then on again to reset. I have run the maximum load for 4 hours with no overheating or issues. Voltage is regulated at 13.38 volts with no load, 13.22 volts at 10 amps and 13.06 volts at the full 20 amp output spec. This is excellent regulated DC voltage especially with the higher loads. I was unable to power up a couple of small inverters and an air compressor with the D40 when all three were able to function when connected to the AC200L Cig socket. When those devices were connected to the D40 load output they would immediately error. I would be cautious with regards to expectations that the D40 will power all loads under 20 amps because it does seem to not prefer some devices even though they were not overloading it when connected. The loads I utilized for testing were charging a Montek X1000 through the car charger and an adjustable load tester.

Powering with LOAD MODE and SOLAR CONNECTED: I connected a 200 watt Bluetti PV200 solar panel that was outputting 7.5 amps and 128 watts to the PV input of the D40. I was not able to output any more amperage when connected to solar and the AC200L input. The limit remained at 20 amps maximum. The LOAD MODE does not appear to accept PV or battery input when in load mode and connecting either does not increase the output during load mode.

Display of DC output on the AC200L screen and app. Previously I could not see any DC output on the screen or app. I was given a firmware update from Bluetti recently ARM version v2099.08 which resolved this issue. I can now see the DC output from the AC200L and app. PROBLEM RESOLVED.

I did not test the battery charging feature but have no reason to doubt that it will work. I suspect that most users will be primarily interested in the load feature first and battery charging capability second.

**SUMMARY:**The D40 allows a higher 20 amp 12 VDC output that the Cig socket on the AC200L but does not offer the full 30 amp output of previous models. You can pull 10 amps from the 200L cig socket and the 20 amps from the D40 and reach a combined 30 amps if that meets your use needs. If you think of the D40 as a DC to DC battery charger first that happens to be a charge controller with a 20 amp load output you will not be disappointed. If you are relying on being able to start and successfully run all devices that use 20 amps or less I would test them first before a full install in case a necessary device is not compatible.


Thank you for the D40 review.

I noticed that D40 can charge different battery types (AGM, LFP, lead acid). Does it have a separate charging profile for each battery type?

Separate voltages listed for different battery types but unsure of differing charging parameters other than voltage

Scott I have not able to test DC loads as I was waiting for my Pecron 1245 which I will be using as opposed to solar as it is completely inefficient to rely on while traveling. I have seen YouTube videos using the AC 200L connected to the Pecron getting 500 watts input via a simulated solar input. This should be sufficient for our needs as output requirements will be small. So my biggest voltage requirement will be a Planar 2 kw diesel heater as the other 12 V requirements will be small. My fear is that I will have to put the D40 in Load mode every time before I want to use 12 V items. I am researching use of outside LED lighting 120 V power supplies being used for 12V DC use and I think at 30A. This would be a inefficient use of the 200L as it uses AC power but it would remove my need for the DO and no need to put it in Load mode all of the time. What do you think?

The D40 will stay in whatever mode it was set to when last used. No need to select load mode each time used. I would be concerned most with will the D40 start and run your diesel heater. I had a few items that I was unable to run even though they were well under 20 amps and would operate from a cig socket on my EB3A which only has half the output of the D40.

Scott, I will let you know what happens with that. I hope that I am successful. My other thought for powering my 12 V DC items would be an AC connection to a 220 transformer (I live in Poland and use 220V AC and not 110), to 12V DC which is an inefficient option but can generate 500 watts at 40 Amps and will work no problem for my diesel heater and everything else. I wanted to use a 12V DC fuse block but found a switch panel that has all power out puts with a fuse

toggle Switch Multi-Functions Aluminum Panel LED Dimmer Switch connected via negative and positive buss bars.


Thanks for an in depth information on the D40 my final analysis is that the S40 is not an option for my camper as it requires more than the 20 Amp output. I have tested and will be using instead a Switch Power Supply DC 12 V 50 AMP 600 Watts. This basically gives me amount of 12V DC power supply which meets my power needs. The only problem I have yet to understand is that the switch connecter is connected to my 200L through a AC plug; my 200L is not showing any usage of power while running 12V DC items. Perhaps it’s utilizing very little power. I have not tested use of my diesel heater, ( waiting for diesel tank connection), but when connected it powers on the heater. Tell me what you think.

Connect some additional load and I think you will show usage