what is common Efficiency Battery power to AC power ??

I am using 11000VA techfine Inverter.. I saw when the Output (Load) is 2.35KVA and 2.29Kw
and the Battery discharging current 52A and Battery Voltage 51.9V..

calculating the output i find the efficiency is only about 85%.

is it normal (good ) ? or it is a bad Inverter efficiency ??

You're probably not hitting a higher efficiency due to the relatively low load (compared to the inverter rating) on the inverter. You should see a higher efficiency at higher loads. I can't find any detailed datasheet on your inverter; many high end tiers provide an efficiency vs. load curve.

Sounds quite low to me, but I only have experience of Solis inverters. I measured about 85% for round-trip efficiency - i.e. grid charge of batteries and then back to AC again, so about 92% either was (assuming it is the same efficiency in each direction).

But my first question would be how are you measuring it, or rather how accurately are you measuring it? A small measurement error, especially easily made on the AC side with inductive loads could change the efficiency measure quite a bit.

i am using data provided by the Software of the inverter. so it has all information about the load and output.

andydarwin said:

i am using data provided by the Software of the inverter. so it has all information about the load and output.

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One thing you might be not accounting for is the inverters demands, not sure about every brand but the ones I've come across don't display the wattage the inverter uses in their software. My SRNE is 2kw but uses 30W give or take on its own which might not seem alot but at low loads can make the inverter seem very inefficient if not taken into account especially when a higher output inverter like yours will likely have much higher demand.

right Now ....i check the Data.. PV power generated is 5.37Kw , Active Power 948w (generated power 1kw) . and Battery Charging at 57A , 54V ..

calculating the energy Lost is 5370 - 948 - (57x54) = 1344w .. which is about 23%.

this is very Bad Efficiency inverter Doesnt it ???

right Now ....i check the Data.. PV power generated is 5.37Kw , Active Power 948w (generated power 1kw) . and Battery Charging at 57A , 54V ..

calculating the energy Lost is 5370 - 948 - (57x54) = 1344w .. which is about 23%.

this is very Bad Efficiency inverter Doesnt it ???

Yep. Good efficiency are around 95%.
None are 100% as there will always be heat loss etc.
Cheaper inverters tend to have less efficiency.

IF its an AIO then its also powering the SCC and other electronics as well leading to its higher "loss"

Note that when you read the data, you might or might not get the simultaneous readings for PV, AC, battery, grid, etc. If you get last-second's AC data and this-second's battery data, for instance, it might look really bad. My GoodWe grid-tie inverters used to show more than 100% efficiency between solar input and AC output (and I couldn't get anyone there to recognize the issue).

Also note significant figures and you can be off by at least one on your last digit, so your battery current is only within 2%, you are only running at 20% load, you kinda want to do KVA, so you are at 87% +/- 2-3%, so I'd call that pretty good. I'd want 90% but I wouldn't obsess about it. In fact, I don't, I'm more worried about battery SOC over the day, solar production, and how many days of autonomy I appear to have.

Your best bet is probably to take an entire day's energy (KWHR) numbers and see if you can mung them into some round-trip efficiency number.

For the last 3 months discharge KWH/ charge KWH = 89% for my Sol-Ark 15K with Pytes V5 batteries.

Oldphile said:

For the last 3 months discharge KWH/ charge KWH = 89% for my Sol-Ark 15K with Pytes V5 batteries.

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So that's battery efficiency? About the 90% I'd expect. The inverter and SCC are going to add a few more percent, but again the real question is 'do I have enough'?