When buying 9 volt batteries, you might want to consider a rechargeable Lithium Polymer 9 volt batteries. As far as I know, iPower is the only company that makes rechargeable 9V lithium polymer batteries. Their batteries are the same size as a 9 volt alkaline battery.
They also have approximately the same capacity as an alkaline 9V–the iPower lithium polymer is rated at 500 mAh, and the “professional” version is rated a 520 mAh. They will actually outperform a 9 volt alkaline battery in high drain applications.
Lithium Polymer batteries use a new gel-type electrolyte. This gel has an energy density that is 20% more than typical lithium ion batteries. They also last 2 to 3 times longer than rechargeable 9V NiMH batteries, and they hold their charge longer. See this forum thread with a discussion of the performance of this battery.
They do, however, require their own specific iPower charger–you can’t charge them in a NiHM battery charger.
iPower batteries are available from Battery Junction. The standard lithium polymer batteries cost $16.95 each, and the PRO version costs $20.95 each. The charger costs $34.95.
If you don’t need a lithium polymer 9v, you can also get rechargeable NiMH 9V batteries, which are less expensive and don’t require a specific charger.
See also our review of this year’s best rechargeable NiHM batteries and chargers.
Read more! Related stories:
- The Highest Capacity Rechargeable AA Batteries
- The Best Rechargeable Batteries and Chargers Of 2010
- New Lithium-Ion Battery Recharges To 90% Capacity In 5 Minutes
- LiFePO4 Batteries: A Breakthrough For Electric Vehicles
- The Best iPhone Battery Pack
- The PowerGorilla: Flexible Portable Power
- Toshiba Dynario Fuel Cell Device Charger
- Is This The World’s Most Efficient Windmill?




{ 15 comments… read them below or add one }
Interesting…
But what do people use 9 volt batteries for these days?
I don’t think I’ve bought a 9 volt battery powered device since I got my last radio-controlled car. (That would be about…oh…20 years ago. And can I just say that the Ferrari Testarossa did not handle carpet as well as I thought it would.)
- Aaron Dalton, 1GreenProduct.com
I’m sure many toys still require 9V batteries but as an adult there are also many applications for 9V batteries, clock radio back-up, all forms of smoke detectors, radon & Co2 detectors, stud finders, telephony toners, both toner and wand. There’s plenty of things out there, just because you don’t use them doesn’t mean someone else doesn’t.
I use 9 volt both for the electrics in my acoustic guitar as well as my smoke detector.
I’m thinking about getting these for work (community college). We have 3 wireless mics for our auditorium and almost all of our smoke alarms and other sensors use 9v batteries. Be nice to have a rechargeable that doesn’t drain down when not in use, recharges more times than NiMH, and doesn’t contain any heavy metals.
most hand held test equipment is 9volt
Karl, you’re right. I forgot about all the Fluke DVM’v and cable testers we have. They’re all 9v.
Virtually every electric guitar effects box uses 9v.
and so do many metal detectors
Do these batteries hold charge well? The smoke alarms in my house use 9V as backup to the mains.
To Power Crazy:
Lithium polymer batteries hold their charge longer than NiMH batteries. Not sure of the exact specs….
Justin
I’m Golden from one of the leading battery manufacturers in China.I have read your comments carefully.And I think I should give you a clear answer.
First,about the usage of 9V batteries.You can use them in microphones,smoke detectors,testers,medical machines,etc.
Second,about the compare of Li-po 9v battery and other 9v batteries.Li 9v batteries do have higher energy density,so its capacity is higher than other rechargeable 9v batteries.
Third,about the cycle life.It depends on the charge and discharge methods.The cycle life of li-po and nimh should be almost the same if you use them properly.
If you are interested in discussing about batteries with them,you can add my msn: goldengpb@hotmail.com
I will answer your questions patiently.
I own the 500mAh I-Power and they are worth their weight in gold I have had mine for over a year. I use them every day in a portable scale to do inverntory for restaurants 6 days a week and they last about three times as long as a reqular 9-volt and twice as long as a stantard NiMH.
They are expensive at first but they will pay for them selfs. They will hold a charge for months and they charge in 35 mins to 1 hour which is quick for a rechargeable. I speculate they will last as about as long as a computer battery so probable years and they are actually a little lighter than a standerd 9-volt. If you do buy you will be sold on these guys…
P.S. Leave the charge at home I have forgot mine at an account and it was gone the next day.
How do these compare to the 9.6Volt NiMh batteries as far as nominal voltage under load?
I use mine for in ear monitors and lower voltage batteries causes it to think the voltage is too low and the sound drops out and the low voltage light starts blinking.
I know Lithium hold their voltage very well, but I don’t know if its enough to compare to the higher 9.6V.
Nominal Volts of 8.4 of the Lithium is a whole volt lower than the 9.6 Volt of the NiMh.. but I don’t know if “nominal voltage” is that different.
Can you help me in my quest?
I’m curious about their effectiveness in smoke/carbon monoxide detectors. Those give warnings to change batteries when the battery drops to 7-7.5 volts, which gives them a 30 day lifespan from that point where they’ll beep constantly. For alkaline batteries this is measured almost exactly, but with rechargeables having a longer plateau of voltage before a steeper drop, would these batteries be able to provide the manufacturer’s “minimum safety requirement” for batteries of that 30 day warning time from when it hits 7 volts?
If you’re interested, check out my new website at http://www.batteryblaster.com.
Cheers!
Jamie
can you run these through a adjustable regulator to work at 3.7-5v? Just curious, I’m a noobie and want 3.7 through 5v but not run 2 rechargable batteries in a series.