Rechargeable 9V Batteries - High-Performance Lithium-ion Battery 4 Pack with 4-Bay Speed Charger - Leak-Proof Ultra Long-Lasting 8.7 Volt 1300x Cycle Times with a 10-Year Shelf Life

Good price Fast delivery Works well What more could you ask for?

I purchased these for my wife to use in her "Tens" unit. The tens unit came with nickel metal hydride batteries (NiMH or Ni–MH), and she was constantly recharging two batteries a day to keep the unit going. After I installed one of these Li-on batteries in the device it allowed my wife to use the tens unit, (during the day), for two days straight, and it still had power remaining. I am very "picky" about Lithium-Ion batteries, and these were a quality build. ***UPDATE*** I cannot recommend this set, because it does not offer a transformer or power source, and additionally has no way to discharge and recharge the batteries properly. I found two of the four batteries to only supply 2.4 volts and a little over 7 volts on the second one. They should charge to approximately 8.4 volts DC which in our situation was required to properly operate my wife's "Tens" unit. It is standard for a 9 volt Lithium-ion battery to charge to approximately 8.4 volts, and not the 9 volts as stated, but it should provide the needed voltage, and current for a lot longer than a regular, alkaline, or Ni-Mh battery. Too many of these battery/charger sets offered, want you to plug their charger into a laptop USB port or provide your own USB charger, which may not provide the needed current to each channel of the 4 charger ports. If they want their product to operate properly, the manufacturer should provide the proper charger with these units. Especially at the price of this packaged product .

I just started using them, I haven’t used them much to get a great review. But it works well so far.

it work's! i charge and recharge with no problems

This company went above and beyond. Replacement of charger, and so quick to respond. I’ll be suggesting this company to my friends. Batteries are top quality. Thanks so much….this type of customer service is rare.

Much longer lasting than I expecting. Using in my TENS unit and they last for weeks for an hour usage per day. Outstanding.

Work really well and charge really fast. Excellent quality!!

Holds charge well in storage. Lasts long in use.

it works fine, satisfied, packed properly, charged fine,

just what i expected. 4 rechargeable 9 volt batteries wirh charger. works well.

Great charger great batteries

Good product. The charger is compact and it came with already charged batteries. Delivery on time and well packaged.

Product was ok but the seller not providing invoice even after requesting for 4 times.