Tenergy'xa09V NiMH Battery
Lithium-Ion Batteries, High Capacity 250Mah, Tens Unit, Metal Detector, Lithium Chloride Batteries, And More (4 Pack) ; 250Mah'Xa0Rechargeable 9 Volt Batteries, Lithium Ion Batteries
Results of our analysis:
We analyzed 55,953 reviews for 88 products in the 9V Batteries category.
We then analyzed 33 reviews for this product. Of these, 6 reviews were recent.
100% of reviews were positive.
Final Score:

7.79 out of 10, based on these factors:
Common Questions
Is this 9.6 volts or 8.4?
When fully charged with a Tenergy charger, both batteries read 10.3 volts.
Where is this manufactured?
They suck, I advise you to buy regular batteries.
Do you know the voltage of the batteries? It has to be a multiple of 1.2 volts.
The batteries pictured as defective were probably rapid charged and unattended causing the swelling over heating and the end result...poof magic blue smoke.
Is it possible to use it for high draw current applications?
They don't have a charge for a long time in or out of application, so I keep mine on a charger to stay ready.
Will they work with the spyder fenix paintball gun?
Yes, a spyder fenix paintball gun might need a 9v battery.