STK EN-EL9 EN-EL9a Battery Replacement for Nikon D3000, D5000, D40, D60, D40X

Very good choice if you need to replace your current battery or get them for back upPower. The work beautifully. Fast charging, easy to use and a charge lasts a good while.

I usually purchase "prime" batteries for my better photo gear, but good results from the experiences of friends made me take a second look at these.The STK's Nikon EN-EL9/EN-EL9a Battery is designed to work with a variety of Nikon D-series cameras. It is rated at 1400mAh, whereas the original Nikon EN-EL9 Rechargeable Li-ion Battery is rated at 1030mAh of power. Either these from STK or the original use the Nikon MH-24 charger.Bought a pair of these for use with my DSLR Battery Grip, which has been in service for a couple of years now. When one of the Li-ion EN-EL9 substitute batteries from another third-party seller showed up as swollen on one side, I knew that it was time for a change. As an added note, be very careful when messing around with a swelling Li-ion (Lithium ion) battery as these can be quite dangerous. Once a Li-ion battery starts swelling, its been damaged and must be disposed of in a responsible manner. They can explode and cause fires. Enough said.Have put these through a number of use cycles in the battery grip, and so far they perform as well as the original Nikon EN-EL9 Li-ion batteries, and at a much more reasonable cost. One cannot ask for more than that.JW ▪ 4/15/2014

I have an old D40, had always had exceptional battery life with it, but decided I needed a new backup battery when one of my Nikon branded ones stopped consistently charging. Turns out it was the branded batteries not seating correctly in my official Nikon charger. These batteries solve that issue. As newer batteries that I treat better than my originals, they hold charge much longer, and seem to cycle better. That could be that I know how to charge Lithium batteries better than in 2008, or it could be they are better built.Either way, these are a good product with a better-than-original sales price.

These batteries were delivered promptly. They are listed as both EN-EL9 and EN-EL9a on the outside box. The battery itself lists only N-EL9 and they measure 7.4V output. This is the specification for Nikon's EN-EL9 battery. The EN-EL9 'a' version specification is for a 7.2V battery. What this means, in regard to a camera that uses 7.2V--if any--, is unknown to me.The battery works fine in my Nikon D40X, but with the battery's rating at 2000mAh, it remains to be seen whether it lasts twice as long as the standard 1000mAh battery. Even with new battery technology, as it is physically the same size as the OEM battery, I would strongly suspect that it doesn't last anywhere near twice as long. If it lasts the same length of time, I'll be happy to have it as a spare battery!!The price (I paid $9) was great, but nobody gets 5 Stars unless I really love it.

Arrived quickly, Charged fine in the Nikon charger and worked in the camera. Haven't tested it for battery life yet but if it performs less than the factory battery I will revise my rating. Using in a Nikon D3000.Overall Recommendation: I wouldn’t hesitate to purchase this product.Update September 14, 2016. I've been using this for over a year in conjunction with the original camera battery and it still performs well.I paid full price for this product. My reviews are honest and reflect my opinion on the product based on the advertised price regardless of the price I actually paid.If after extended use, there are any significant changes or the product fails to perform as expected, I will update my review.Thank you for taking the time to read my review and feel free to ask any questions. If you found this review helpful, please click “Yes” below.

Bought this battery to supplement the original Nikon battery that comes with the Nikon D40. The original Nikon battery lasts a very long time, before it needs charging, so have rarely needed a spare. Bought this STK replacement to have as a spare, on those rare occasions when the original Nikon needs recharging before we are finished shooting for the day. Bought this one due to the low price and good reviews. So far no complaints. It charged up quickly and fits the D40 perfectly (not too tight a fit as some generic batteries are). Haven't had to use it, for its intended purpose as a backup, so I can't comment on how long it lasts compared to the original. But if it lasts just 60 to 75% as long as the original, I will be happy with it. For the price, it is a great replacement battery.

I bought this about a month ago and had been planning to get a full charge discharge cycle out of it before commenting. However, after hundreds of photos (150 tonight alone) it is still going strong on the first charge and I wanted to check this off my ToDo list!I was worried about purchasing a third party battery but this seems as good or better than the OEM Nikon battery that came with the camera. And of course to buy one from Nikon it is still the same price as 5 years ago when I bought my D40X. That despite the revolution in cost reduction in Lithium Ion batteries being driven by the lap top, cell phone and EV markets http://handlemanpost.wordpress.com/2013/12/24/cost-projections-for-lithium-ion-batteries/ . So far so good with this and the charger that I bought with it is great, no bulky cord.