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Axpert losses


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Every time this question comes up it goes roughly like this.

1. We ask how you measure

2. After figuring out that the measurement wasn't really accurate, we agree the real number is closer to 40 watts or so.

3. Someone like me or TTT comes by and point out that our blue inverters uses only half that.


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25 minutes ago, plonkster said:

3. Someone like me or TTT comes by and point out that our blue inverters uses only half that.

I think PaulF007 is talking about self consumption and the loss in efficiency from the DC to AC conversion of the inverter.

Mine is between 42-57w. (150-300w load)
Got this number by looking at the inverter load watt display and the watt drain reading on the BMV.
Self consumption is between 24-27w (fan speed my guess depending on the load). This is the reading the BMV gives when I put the inverter into bypass mode.

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2 minutes ago, PaulF007 said:

Cool so there is a correct way to measure. How do you measure it?

Any help us always appreciated 



Lol. to be fair, seen a few cases where people measured it using an efergy meter. My comment was tongue in cheek :-)

As I recall the consumption of the inverter itself is around 40 watts, and the DC-AC conversion is around 90%. @viper_za's consumption sounds about right.

Also, to be fair once again, the 48V inverters are always a bit heavier, so a comparison with our (me and TTT) 24V inverters also isn't fair :-)

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I am being drawn in here see I.

7 minutes ago, plonkster said:

comparison with our (me and TTT) 24V inverters also isn't fair

And to be really really fair, between us, mine is 10w with zero load. 

And we have to be even more fair and add the MPPT's power in standby also. 10mA for mine, so I sommer wanted two. So now it is 20mA ... sjoe, I must reduce that. :P

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Okay, the big 48V Multiplus has a quiescent power requirement of 35W. I think we can reasonably assume the Axpert is not going to do better than that. From what I heard of other owners, 45W to 50W is normal.

The 24V Multiplus, as TTT said, is around 10W at zero load for the small one, 20W for the larger 3kva.

Axpert service manual for the 24V 3kva model says 20W at no load. So on par then with the Multiplus... allegedly :-)

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25 minutes ago, TinkerBoy said:

Axpert uses 50w. My Infini uses about 60w. I have a meter that knows what the power factor is and has Class 1 accuracy. I also tested it with a pre paid meter. 


BTW Viper jy moet jou signature verander LOL. Dit is nie meet JDP nie hehe

Was it the 2 Axperts consuming 50w together?


I also recall you having the Axpers floating the bank using the AC charger. Was it at the 2A setting. Thats around 50w

LOL sal hom update ;)

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So to conclude 

The inverter will use round about 50w - 70w to do its thing and could spike to as high as 90w during load and there isn't much you can do about it , apart from maybe going Blue hey @The Terrible Triplett?


Thanks @plonkster and @TinkerBoy I needed to confirm that it is a hardware challenge and not a IO issue. 

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@TinkerBoy Where did you measure the 50w. AC-input, AC-output or on the DC side (BMV)

As far as I could tell I can see no consumtion from the AC-input side from the inverter while running on batt mode. How I tested this: took load and battery readings measured the difference between them, batt was always higher by around 42-57 (This to me is self consumption with DC-AC conversion losses) Then I turned off my main Eskom AC breaker and saw no change in the above mentioned results. 

To get self consumption figure of between 24-27w I did the following. First I looked at the AC-output side reading(load) then I swapped to bypass mode. The AC-output reading stayed the same but the BMV reading changed to the 24-27w drain from the bank.

This to me shows the inverter using no AC power at all and it fits the reason why the Axpert can not start up without a battery bank.

Am I measuring my findings the correct way?

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19 minutes ago, TinkerBoy said:

From the mode it is on. If its on battery mode it will take it from the bank. If on grid from the grid. 

You can do the following test. Remove the load from the inverter and switch the grid feed off. The bmv will show you what the inverter uses plus a couple of watts for the bmv. 

Will test like that tonight also.
Just took a quick snippet of the lowest usage last night on battery mode.


These images shows solarwatts/load at 2:51:15 AM at 55w and battery watts (BMV) at -104w at the exact same time
Keeping in mind this is with 2x 5W LED lights, router, alarm, tablet, TV+Surround sound standby, and also the microwave on standby (showing clock) and whatever the geyserwise uses. From this I am assuming the chest freezer is off at this moment and the Samsung inverter fridge is also not using any major power and should be included in the 55w load.

This gives me a 49w difference between the load and the BMV reading.
How I understand this the 49w consists of what the inverter is consuming on its own to run (self consumption) will test tonight as suggested above but so far I have measured this at around 24-27w.
The rest is losses in DC-AC conversion of the inverter itself and should not be part of the self-consumption calculation. Can we agree on this line at least?
Keep in mind the smaller the load on the bigger inverter the less efficient it runs.

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9 hours ago, PaulF007 said:

... apart from maybe going Blue hey @The Terrible Triplett?



Not going to bite bar to say you made a very good point this morning. This Victron - Axpert comparison, should stop.

We cannot compare the two brands. Not on price, not on quality, not on warranty, support nor functionality. It is two complete different routes to the same end goal.

Victron a choice you make for whatever reasons you have, and you can justify the cost. 

For because of Power Forum, and the wealth of knowledge here in SA from select members (to many to note here) and from @Coulomb in Australia, Voltronic inverters are the best inverters to start a solar journey on. 


Ps. No, I am not swapping over @viper_za, my blood is Blue.

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Mense Blou, soos in koninglik, nie soos in rugby Blou Bulle ... (facepalm)  

Mens kan julle ook nerens vat nie. :P

30 minutes ago, PaulF007 said:

But it was close - even for just a moment - :D

As dit jou happy maak, dink maar so ja, of rook nog van daai goed wat jou so laat dink ... (rofl)

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