BATTERY OPTIONS

[dealgrabber2002]

1) Would you choose sanyo 2500mAh or Eneloop 2000mAh (also from sanyo)

2) Which last longer assuming you have 2 AA:
a) Use 1AA and when it's out, change to the next one?
b) Buy extended tube (if available) and use 2AA at the same time?

Thank you for your input.

-E

 

[mdocod]

1: This depends on intended use and your expectations of cycle life. If you use daily and need maximum runtime from a single cell, go with the 2500 cells. If you can carry a spare cell and don't need the last itsy bitsy bit of juice from each and every cell, then the eneloops are worth the lower capacity for easier maintenance, better cycle life and lower self discharge.
2: This depends on the type of flashlight you are dealing with. I assume LED, but different driver boards are going to behave differently. Generally speaking, driverboards designed for these voltage ranges (0.9V-4.2V type boards) are going to run more efficiently with input from 2AA as they won't have to suck as much current and waste as much energy taxing the cells and won't burn up as much energy in heat just by the simple fact of pulling higher current through wires and inductors increases losses.... However, running more efficiently doesn't necessarily mean you are going to get more runtime. It's very possible that if the driver "drops out of regulation" and steadily dims down when using a single cell, it may be able to stretch out more runtime from 2 separate cells. But that available runtime would be of diminishing output, rather than regulated consistent output.

 

[Mr Happy]

All things being equal, a freshly charged Sanyo 2500 may run a little longer than a freshly charged Eneloop.

However: if you use the 2500's, you will have to remember to charge them every time before you use them, or they might be empty when you need them. If you use the Eneloops, you won't have that worry. It's really a question of whether you want, or need, pick up and go capability.

 

[Zenster]

A 2000mah low-discharge rechargeable beats a 2500 standard rechargeable everytime with the one exception of where you know you'll be using the light so much that you will use up a battery in a short period of time (camping?).

In most cases where you mostly just keep the light on-hand for emergency and intermittant use, the Eneloop will actually last longer due to it's much lower self-discharge trait.

Now going back to the point I made in the first paragraph about knowing that you'll be using a lot of battery in a short period of time, those situations "usually" happen due to not having the ability to charge anyway such as the aforementioned camping or a power-outage situation at home.

So then, the best strategy is to keep your Eneloops charged so that they are fresh(er) when you need them, but to have some Lithium or Alkaline primaries as backup when you can't charge anymore.

Bottom line: standard rechargeables don't make much sense for me anymore, and I now use only low-discharge rechargeables AND I keep some fresh primaries on hand at all time for emergencies.

 

[dealgrabber2002]

1:
2: This depends on the type of flashlight you are dealing with. I assume LED, but different driver boards are going to behave differently. Generally speaking, driverboards designed for these voltage ranges (0.9V-4.2V type boards) are going to run more efficiently with input from 2AA as they won't have to suck as much current and waste as much energy taxing the cells and won't burn up as much energy in heat just by the simple fact of pulling higher current through wires and inductors increases losses.... However, running more efficiently doesn't necessarily mean you are going to get more runtime. It's very possible that if the driver "drops out of regulation" and steadily dims down when using a single cell, it may be able to stretch out more runtime from 2 separate cells. But that available runtime would be of diminishing output, rather than regulated consistent output.

Assuming it's the Ultrafire C3. I know nothing of its driver. 2AA better than 1A for C3?