in Electronics, Public
Lithium Batteries have a voltage between 3V and 4.1V, but recently they have been turned into the 1.5V form factor with some electronics that step them down to 1.5V and custom chargers that know how to recharge them via a special protocol, or for the EBL batteries, they have a micro USB plug onboard.
They are of course not all the same real usable capacity, and I've learned not to trust vendor capacity claims anymore either, due to the amount of sellers that plain lie on amazon. The good news is that Neither Xtar nor EBL lied about their cell capacity as long as you understand that the actual energy you can output will be lower due to conversion losses and some safety buffer to give the cell longer longevity.
Here is a quick summary without pictures:
New Xtar: Rating: 4.15Wh, Charge: 5.5Wh, 3.45Wh Usable discharge at 1A
This is the only lithium battery that drops its voltage to 1.1V to give you a low voltage warning. Other batteries I tested just die with no warning. That alone is a reason to select it. I tested it with my garmin GPS and it gave me 2H of low battery warning before finally dying. Very nice!
It is also the battery that gave me the most actual discharge capacity
Seller is not lying about cell capacity (thank you) which of course is higher than actual usable energy due to conversion losses
New charger is unfortunately bigger than the old one and drops the USB-A output feature to use your batteries as an emergency USB charger
Verdict: this is the best battery I tested and what you should buy as long as you don't need a built in charger like EBL
Old Xtar: Rating: 3.3Wh, Charge: 5.3Wh, 2.7Wh Usable discharge at 1A
This is the older Xtar battery. It had best in class capacity until the newer one that came out with added low voltage warning. There is no good reason to buy this battery anymore, get the new one.
Its capacity is equivalent ot the EBL battery with built in USB charging, so the EBL is more versatile
The charger is very compact and can act as a USB power source, that's a nice feature.
10.6Wh to charge 2 batteries, or 5.3Wh charge per battery
EBL 3.3Wh rating, Charge: 4.3Wh, 2.7Wh usable discharge at 1A
There is no low voltage warning, but the battery capacity is actually equivalent to the old Xtar despite the space lost to the built in charger. The new Xtars last longer than the EBL though.
Interestingly EBLs need less energy to charge than Xtar for the same output capacity, they are more efficient
Big warning: if you try to charge the batteries via USB while they are in use, they are going to output 5V instead of 1.5V. This is unexpected and fried one of my GPSes. You cannot charge them while they are being used.
Deleepow 3.4Wh rating, 3.8Wh charge, 2.4Wh usable discharge at 1A
These battery are not for sale anymore, and they were the least performing amongst the ones I tested.
The 3.4Wh cell capacity is probably untrue with the charge and discharge numbers I got