[greggold]

In the time of lipo shortage, I tried a new brand from PhaserFpv:
GNB GAONENG 650mAh 2S HV 7.6V 120C XT30 LiPo Battery FPV Drone Racing Light Weight LiHV High Voltage

I have been using these lipos to power several 80 cm span 3D planes for some time, and I have assumed being 2S lipos that they should be charged to 4.2 v per cell, total 8.4 volts. I think they perform well.

I today noticed they have a nominal voltage of 7.6v! Until now I have never seen a lipo with a "nominal voltage of 7.6v".

I posted a question on RCG:
On the website it seems all the Gaoneng 2S batteries have a nominal voltage of 7.6v. There is no advice on what voltage they should be charged to. I would appreciate if anyone can explain this. Can they be charged like all other 2S lipos are charged?

Fortunately I received a good reply. The above battery is not called a lipo, its a LiHV, which can be charged to either 4.2v per cell or 4.3 v per cell. It looks the same as a normal 2S lipo, and it performs well.

Oscar Liang provides useful details on LiHV.

https://oscarliang.com/lihv-lipo-drone-battery-hvli/

I plan to check my chargers whether they accept LiHV batteries, or whether they can accept a charge to 4.3v per cell.

[caffeine]

I wonder how much extra capacity you would get from the higher voltage.

[greggold]

You do get extra capacity as Oscar's post has demonstrated. The extra voltage also gives you extra punch if you are using a racing drone. I have a Gens Ace charger that can charge LiHV batteries, I presume to a 4.3v per cell charge. However I am not sure I want to do that as I do not really need the extra capacity, and Oscar says the higher voltage may reduce the life of the lipo.
I discovered what "nominal voltage of 7.6v" on gaoneng lipos means. Gaoneng lipos with 4.2v per cell max have "nominal voltage of 7.4v", and the LiHV's with the 7.6 number means a max voltage per cell of 4.3v.

My smaller 3D planes seem to thrive on 2S lipos with a capacity >500 or 600 mah. One of my best 2S lipos (a 2S 950 mah turnigy graphene) is showing signs of wear (the charger thought a cell had gone over 4.2v and stopped - but in fact both cells were well below 4.2). I have just ordered two gaoneng 850 mah 2S 120C lipos from PhaserFpv, they are cheap and I have been pleased with my 650mah LiHVs (also cheap) which I charge to 4.2c per cell.

[greggold]

I have used the gaoneng 2S 650 120C mah HV lipos some more, and I am impressed with their performance. They seem to beat my best 2S lipos of other brands, even though I only charge them to 4.2v per cell. Based on this result I have bought several 850 mah 2S but have not yet had a chance to assess them.
The voltages written on the lipos may confuse people, and there is no discussion on the gaoneng website. A tiny instruction manual  - the font so small I could not read it even with my reading glasses and a magnifier - is included. I scanned this manual and saved it in highest quality mode, and it is now just legible if you zoom in (attached).

It says lipo cells have 3.7v per cell so 7.4 on a pack means it is 2cell 2S. "for High Votage cell have 3.8V therefore 7.6v mean 2 cels." This statement does not seem to acknowledge the lipo cell voltage varies according to the state of charge or discharge. Are 7.4v and 7.6 v the storage charges? No, for storage there is this statement
"the standard is a 5C% storage charge meaning a 7.4V/2 calls (High Voltage 7.6V/2 calls or 7.7V/2 cels) pack should be stared at 7.6 volts (High
Votage7.8.)". In other words, the writer is trying to say normal lipo stores at 3.8 v per cell, HV lipo at 3.9v per cell.

There is writing on the packs that can be read if you take a high quality photo and enlarge the photo by zooming a pdf. You see that each lipo is labelled 7.6 which according to the above text means its a HV lipo. On closer examination you see "11V" on the label, and if you look even closer it says HV with part of the H missing. 

In conclusion, I believe these are high quality lipos, however you need to enlarge, read and interpret carefully the label and instructions. I hope this post helps...