In A Nutshell
- The best low-discharge 9V rechargeable is the Tenergy Centura 9V 200mAh Low Self-Discharge NiMH Rechargeable Batteries
- The best lithium-ion 9V rechargeable is EBL 9V Lithium Ion Batteries
Low-self discharge 9v Ni-MH batteries have become available in the last few years.
The “low-self discharge” label means these batteries will hold their charge for a year, unlike previous NiMH batteries.
This makes these 9V battery much more compelling, because 9V batteries are often used in applications like fire alarms, where the battery must sit for year or more.
Centura 9V NiMH Battery by Tenergy
9v Lithium Ion Rechargeables
You can also get Lithium Polymer 9v rechargeable batteries, that use a new gel-type electrolyte. This gel has an energy density that is 20% more than typical lithium ion batteries (550 mAh in capacity). They also last 2 to 3 times longer than rechargeable 9V NiMH batteries, and they hold their charge longer.
There are available here: EBL 9V Lithium Ion Batteries
See also our review of this year’s best rechargeable AA NiHM batteries and chargers.