Which kind of AA battery would you use in this light?
 

Philips Saferide 80.

It has a published run time of 1:30 on high. 8 hours on low.

My commute can be as much as an hour. I need the light on high the whole way. So I'll probably recharge the batteries every day at work, most likely taking them straight from the charger and putting them in the light right before I ride.

Should I use 2000 mAh low self discharge batteries like Eneloops or Duracell "staycharged" or should I use 2400+ batteries that will lose a charge over time.

If you're always going to be recharging it daily then go for some good quality NiMH cells with the higher capacity around 2500 mA-hr or even higher. The 'pre-charged' cells that are around 2000 mA-hr are better for situations where you sometimes aren't using them for long periods of time and still want them to retain almost all of their charge - or for low current devices where they don't need recharging for a long time.

I doubt you'll be able to get an hours runtime out of NiMh batteries, I had a hard time getting more than a half hour out of mine. I'd buy extras and plan on a lot of changes to use that light.

I guess I am wanting the best of both worlds. Here is what I'm running in my Dinotte 140L:

http://www.amazon.com/gp/product/B00...?ie=UTF8&psc=1

In general, if I can't use Eneloops in it, I'm not going to buy it in the first place.

The Imedions linked by westrid_dad are the same thing from a knockoff supplier, though Maha is pretty good. I've bought some store brand LSD AAs as well and they work fine, but anymore I just spend the extra 50 cents and buy the Eneloops.

For a light that I'm going to use every day though, self discharge really isn't an issue and I'd probably use up my old batteries that I'm trying to kill so I can replace them with Eneloops.

Eneloops aren't just for infrequent applications; they hold capacity better over multiple charge cycles such that after a hundred or so cycles they have better capacity than batteries that advertise higher initial capacities. If you plan on using the light for a year or more you're still better off with eneloops.

Tonight I went for a ride and used 4 Energizer's I took out of my camera that were rated at 2300. I charged them in my smart charger, and put them right into the light. It was on high for almost an hour and a half before it switched to "eco mode."

I plan on using the light for a long time. I don't mind replacing the batteries every year or so if it means having enough light to get me all the way home. I'll keep the LSD batteries in my bag in case my commute gets way longer than expected.

Normal NiMH loose 10% during the first day so 2500 energizers (what mine are) will still beat 2100 eneloops.

If you have a lot of $ get the 2500mAh Eneloop XX. I have a set for longer missions.

ps... I thought the saferide switched itself to low based on a timer, not battery capacity.

That hasn't been my experience. I have some older Energizer 2500 mA-hr regular NiMH cells that I've used regularly for years in my GPS and they still run longer than my newer Eneloops as long as I charge them shortly before use.

There was a bit of buyer's remorse with my first ride home with the Saferide. I used the batteries that they supplied and it switched to low when I was just 2/3 of the way home. Turns out that two of their batteries have trouble holding a charge. But with decent batteries, it seems to work as advertised.

How are the Eneloop XX batteries?

I have tried a lot of different rechargeable AA batteries, but I'll have to say that I've had the best performance from Eneloops. If you buy on line, they cost only marginally more than other rechargeable batteries.

I also use the Maha Imedion 2400's in my Dinotte taillight. They last 8 hours and the Eneloops last 6 hours.

I have some Imedions that weren't any better than regular rechargeable NiMh batteries. I've still got them in my weather radio, but don't use them for lighting after switching to Li ion.

I have Energizer rechargeables that have to be 5 years old and still work.

Which ones?

I think they were these. I bought them about 5 years ago, and they were similar to these if they were different.

Mine were the 2,100 mah version.

Phillips Saferide is also made in a dyno-hub powered Version..
one on the fork crown and the battery one on the handlebars would be a real bright combo.