Okay, I pulled the trigger and bought the Nikon SB-600 Speedlight I had asked about in another post. It's in the box, refurbished by Nikon. . . includes the carry-pouch, diffuser, off-camera stand, unopened Nikon SJ-1 Speedlight Color Filter Set, and user manual. All in perfect condition, for $86 total.

Now I'd like your experienced opinions on the best batteries to get for it. I'm thinking rechargeable batteries and a charger would be more sensible than regular alkaline, but I am open to your valuable input.

Thanks!

PSA

While you get a lot of the gallery suggesting Enerloop (and they are not bad - just expensive) the absolutely best deal is - believe it or not - Ikea's private labeled NiMH batteries. They carry two versions - high and a low capacity. Japanese produced (by the same mfg as Enerloop Pro) and the high capacity/high charge rate is a top performer - and the price is $7 for a 4-pack (Enerloop Pro will run you about $20-25 per 4-pack). Listed capacity 2450mAh - most of the the cells test out around 2600mAh.

Oh - and they also have some very good chargers - one of the models will take 1 to 12 AA and/or AAA cells at the time (with individual cell charge regulation)

PSA

While you get a lot of the gallery suggesting Enerloop (and they are not bad - just expensive) the absolutely best deal is - believe it or not - Ikea's private labeled NiMH batteries. They carry two versions - high and a low capacity. Japanese produced (by the same mfg as Enerloop Pro) and the high capacity/high charge rate is a top performer - and the price is $7 for a 4-pack (Enerloop Pro will run you about $20-25 per 4-pack). Listed capacity 2450mAh - most of the the cells test out around 2600mAh.

Oh - and they also have some very good chargers - one of the models will take 1 to 12 AA and/or AAA cells at the time (with individual cell charge regulation)

In checking out Eneloop, I found this:

This package (Panasonic K-KJ17KHCA4A Eneloop Pro Individual Cell Battery Charger with 4 AA Ni-MH Rechargeable Batteries) contains the BQ-CC17 charger and four eneloop Pro batteries. People often ask me whether it is worthwhile to pay extra for this 'Pro' package over a similar 'regular' package. So here is a breakdown on the Pros and Cons of going Pro:

- The rated capacity of eneloop Pro AA cell is 2550mAh, or 27.5% higher than that of regular eneloop cell (2000mAh). My measured average capacities using the La Crosse BC1000 Battery Charger are around 2560mAh and 2080mAh, respectively.

- The cycle life rating of Pro is only 500 cycles, verses 2100 cycles for regular eneloop. More about this later.

- The advertised charge-retention rate of Pro cell ("85% after 1 year") is not as good as that of regular eneloop cell ("90% after 1 year, 70% after 10 years"). Those rating are consistent with my own long-term test results. Of course in real life this hardly matters.

- The Pro AA cell is slightly thicker than regular eneloop cell, so it might not fit in appliances with extremely tight battery compartments.

The chargers included in the Pro and Regular packages are identical except for color. So this is not a factor. See my review on BQ-CC17 for details of this charger.

[Capacity Matters?]
Obviously higher-capacity for batteries is better, because it gives you longer runtime for each recharge. This is especially true in the old days of NiCd batteries, since you are supposed to drain them completely before recharge (to avoid 'Memory Effects'). With pre-charged NiMH batteries and smart charger such as the BQ-CC17, you can choose to top-off your batteries anytime. So having higher capacity is less critical.

Just for example, let's say you are using rechargeable batteries in your external photo flash unit. Assuming a set of regular eneloop cells (2000mAh) can give you 1000 flashes, then by changing to Pro cells (2550mAh) you can expect 1275 flashes. But unless you actually need to shoot over 1000 pictures in one session, the extra capacity does not offer you any advantage.

[Cycle Life Matters?]
This rating refers to the number of deep-discharge cycles a battery goes through, before its capacity drops to 50% of original value. That means:
- Regular eneloop starts from 2000mAh and drops to 1000mAh after ~2100 cycles
- eneloop PRO starts from 2550mAh and drops to 1275mAh after ~500 cycles
Note that those ratings are based on tightly controlled test conditions. In real life your numbers will likely be less.

Assuming linear degradation of capacity, we can estimate that after 250 cycles:
- Regular eneloop --> 2000mAh - 1000mAh*(250/2100) = 1881mAh
- eneloop PRO --> 2550mAh - 1275mAh*(250/500) = 1912mAh
That means shortly after 250 cycles, the regular eneloop cell will actually out-perform the Pro!

[Bottom Line]
If you have mission-critical applications that demand the extra capacity offered by eneloop Pro batteries, definitely get this Pro package. Otherwise for similar cost, you can get the regular package plus another 4 regular eneloop (or the equivalent AmazonBasics Pre-Charged) batteries. So now you have 8x 2000mAh eneloop batteries instead of 4x 2550mAh eneloop Pro batteries. This approach offers you almost 60% more in total battery energy. Most importantly, you now have a set of spare batteries to swap in whenever the first set runs out, so you'll never be out of action while batteries are being recharged.