Away to pull the trigger on one of these lights and wondered what batteries current owners had the best results with.
Brian
Quality batteries are quality batteries and generally not much more pricey.
I have some AW 16340’s which I have no complaints with. And you likely won’t go wrong with them.
Just stay clear of any of the blue or grey Ultrafire crap. Seriously not worth the effort of ordering, let alone actually paying any money for them.
BTW - I think most ‘good’ 16340’s are around 700mAh or so. If a vendor is claiming way over this, then chances they are crap batteries and will likely only manage 200mAh at best.
The Solarforce V2 880mAh is like a 18350 in the size of a 16340…down side: you have to unwrap it and remove the protection pcb to get it to fit in the S10.
http://www.solarforceflashlight-sales.com/product_detail.php?t=BC&s=23&id=363
Also, the AW IMR 550mAh batteries give you max brightness and fit easily (still unprotected though). Honestly, I ran mine on UltraFire “1,000 mAh” batteries for a while and never had a problem, but I can’t recommend that.
I love my S10 and would choose it over the others, if someone said “give me all your lights but ONE!” 
I use Yezl 16340’s in my S10. I have also tried AW IMR’s.
The AW IMR gave 55 minutes on high. The Yezl gave about 1h15m on high.
Thanks for the replies its appreciated.
I have used AW’s in previous lights I have owned and couldn’t really fault their performance but it has been a while since I bought 16340 batteries so just wanted some views on what others were using. Would be good to know what others thought of the Nitecore and Eagletac 16340’s as I can get these easily from UK dealers as well as the AW’s.
Is the Yezl an IMR? I have had 16340’s that had longer run time than the AW IMR but didn’t have the output. I like IMR cells because they have awesome output. I have some Efest IMR cells on order now. They are rated the same 550mah as the AW’s but I think I have read that they have a little better performance yet.
I use nitecore NL166. I do have a discharge graph if your interested.
https://www.fasttech.com/products/1420/10001848/1134001-nitecore-nl166-rcr123a-650mah-37v-rechargeable-li
Thanks again for the replies.
I would rather stick with protected batteries so looking like I will stick with the black label AW’s or try some of the Nitecore NL166’s. I assume there are no issues size wise with the NL166’s fitting in the S10?
The Yezl isn’t IMR.
You will only need IMR’s extra output if the light isn’t current regulated though.
In the Trustfire mini-01, the Yezl managed 2.2-2.4Amps. The AW IMR managed 2.8-2.9A. But in a light like the Olight S10, there isn’t any difference between the 2 cells in terms of output. You just get less runtime with IMR.
I wouldn’t buy or use any of the xxxfire branded batteries, I’ve used them in the past and its too much of a hit or miss with their performance. I want batteries I can trust and I know what I get from the AW’s and hoped there were alternatives that were as good if not better. Nitecores seem to be what some are using and I know they are easily available from UK sellers.
Happy for others to pitch in with their suggestions as it will be Tuesday (due to Bank Holiday) before I order the light.
Have a look at hkj’s test on 16340’s. should give you a few choices.
Did that already mate 
Its always good to hear what owners experiences are and having been out the loop for a while, brings you up to speed with what’s available quickly.
Keep an eye on eBay for a couple of uk shops selling Yezl 16340’s. there aren’t any at the moment.
Will do cheers.