Honestly, I've heard so much about charging circuitry, etc., not working on 3rd party batteries that I just bought an extra pair of Nikons. Maybe I wasted $20, but that's one less thing I have to worry about.
I have used after market batteries, though not on my D7000. My experience was not encouraging, one failed so early it might have been DOA. The replacement is still around and still appearing to work but it never gives the correct response to charging. On balance I would urge the use of makers devices rather than a 'Joe Soap' special.
I bought one of those "fully coded" cheapo ones for like $25 on Ebay. It worked fine from a recognition standpoint initially (camera didnt yell at it being 3rd party, battery meter worked, etc), but the battery cells were junk after 3 or 4 charges. Waste of $25. I would have just bought the Nikon one if I could do it over.
I have never heard of a Lenmar. I would certainly not buy an unknown quality battery just to save $9 on something that has a useful life of a few years. That's false economy. I only buy genuine Nikon parts and especially if it affects the operation of the camera.
At the risk of being branded a heritc or worse a pariah,,,, I'll offer you my thoughts.
I have found the EN-EL15 battery more than adequate for my shooting needs. As long as I remember to charge it the night before a heavy shoot, I have only once run it low to the point I was worried.
But when I bought my D80 I quickly found having a second battery was a must. When I went to the local B&M to buy the Nikon EN-EL3, the rep recommended the Promaster replacement. It boasted a 2500mah rating compared to the Nikon 2000mah and was cheaper. At first I was hesitant, but the rep assured me its was every bit as good and backed it with a money back if not satisfied. I have since handed all my D80 gear to the granddaughter and some 5 years later the Promaster battery is still plugging along with the Nikon battery without issue.
I'm not familiar with Lenmar, but looking into them, they seem to be a global reputable company. But looking at their replacement battery, it's only 1750mah compared to 1900mah Nikon. So to me the $9 difference is eaten up in available power rating, so in that case it would seem to be a wash and I personally would choose the Nikon.
But I would stay away from the e-bay sub-$20 no brand name specials for many of them are junk.
Just my 2 cents as I put on my flame retardant suit!!!
>At the risk of being branded a heritc or worse a pariah,,,, >I'll offer you my thoughts. > Damn, it's Pariah Pete.
Actually, you make a good point. I just asked my MotherInLaw what the spare battery is for the D5000 I gave her when I upgraded, and it's a ProMaster. I used the ProMaster and the Nikon interchangeably in the 5000 for quite some time, and never had a problem.
I agree with those who advise using Nikon brand batteries. If for no other reason, there is the following statement on page xvii of the D7000 User's Manual regarding the warranty:
"The use of non-Nikon electronic accessories could damage the camera and may void your Nikon warranty. The use of third-party rechargeable Li-ion batteries not bearing the Nikon holographic seal shown at right could interfere with normal operation of the camera or result in the batteries overheating, igniting, rupturing, or leaking."
Well, I guess I am a heretic too. When I bought my D7000, I ordered a second battery from the vendor. It was a non Nikon, and I don't remember who made the spare battery? However, it is still working over two years later. I charge it along with the Nikon battery and run both together. One in the camera and the other in the non-Nikon grip.
In my D700, I have the same setup. I purchased it second hand and it came with a Nikon battery and a non Nikon battery. Both batteries work just fine.
I agree however, stay away from the eBay batteries. Buy a spare from a local camera shop or one of the well known big internet Camera stores.