For a very long time by bicycle light was a lantern light with a Radio Shack lead acid lantern battery. It worked fine even in Oregon where it rains every day. Be careful not every new lantern light will take a lantern battery. The Dorcy I got came from Dollar General and has 100 lumens. It has a 4 AA cell adapter. I have had other lantern lights with a 4 D cell adapter. Lantern batteries have 4 F cells which is a longer D and they are real cheap for their capacity. Lantern LED lights are getting good enough that you may want to keep a few of these around. There is also the Rayovac but some Rayovacs with the AA adapter are actually 3 volt. With the higher voltage you don’t need a boost regulator which increases efficiency. My own experience is 4 AA NiMh have about twice the performance as 1 18650. The Dorcy actually has a good beam pattern with a mid range throw and the big lens does a good job unfocusing rain drops. The Life Gear light also looks interesting. I needed a low power light that will run all night. I will be sealing the power switch and lens with Slime rubber cement. Batteries Plus will sell you a lead acid battery or D cells in 9 10 and 12 amp hour capacity. I will be sticking with my ridiculously expensive X2 Power AA. The dorcy says it will run for 8 hours but I am expecting 100 lumens per watt efficiency. The worlds greatest bicycle tourist Ian Hibell said if you look poor the thieves will leave you alone.
Some lantern batteries container F cells. Some use D with a cardboard spacer. Some use “Heavy Duty” instead of Alkaline. Make sure you get Alkaline F-cells!
I have not seen many F alkaline, all F cells i removed were carbon zinc, all alkaline 6V batteries had alkaline D cells inside.
The Dorcy came with carbon zinc AA which is why I am expecting longer life from rechargables. Salt from the oceans plays hell with electronics. So I am going to buy a cheep light with minimal electronics that I can replace often. What I don’t use I leave in a little free library.
But you will not get better runtimes from nimh AA. their capacity is lower than alkaline AA, and at moderate load, (probably no more than 500ma, most likely less,) that your dorcy runs at, nimh offer little to no advantage. I comes with 4AA adapter in order to keep weight down so it can float, with 6v lantern battery it will work just fine, but it will most likely sink, it also tells me that current draw is pretty low. I’m pretty sure it has no drivers or regulators, it has a resistor, that is matched to 6v battery, so using 4.8v, or 3.7v battery (4nimh aa, or 1 li ion) will run it too dim.
Even at 500mA nimh massively outperforms alkaline
I have seen 0 evidence of that, care fo show any?
HKJ is a member here who amassed a large database of consistently performed battery tests. You can see comparisons here. Be aware that alkalines are near the bottom of the lists in the dropdown menus:
https://lygte-info.dk/review/batteries2012/CommonAAcomparator.php
Comparing the same size cells, you can see that while at low loads alkalines have more capacity, at even moderate loads, NiMH are actually able to deliver more energy. Furthermore, while alkalines have higher voltage when new, the voltage under low loads falls to a similar level while the battery is still half charged or more. Under moderate loads, the voltage under load for the alkalines falls very rapidly below that of the NiMH.
The battery comparator makes it easy to see the alkaline staying slightly ahead at 0.1A, being clearly inferior at 0.5A, and being effectively useless at higher than 1A.
If you find flashlight reviews where the output is tested with both alkaline and NiMH, you will typically see performance on high modes decline fairly quickly on alkalines due to this.
I see your point in general, but In this particular context, battery needs to be 6v to operate properly with resistor installed. In this particular light, nimh will offer no advantage.
Possibly - and possibly not. The loaded voltage of alkaleaks may drop lower than NiMh, depending on the load.
The load was designed to work with AA, so it is pretty low.
The NiMh cells will likely outperform the Alkaleeks over most of the discharge curve. Plus instead of throwing them away and adding them to the waste stream, they can be recharged and reused. At the very least, it is worth trying them, rather than just speculating that they won’t work based on guessing how the light might be setup.
There is nothing to guess, I took such lights apart before, I used resistors in my builds, i know how they work. But yea, try it and let us know.
It looks like there is a PR flange bulb in there. There are 3 clamps holding it in and I am not going to risk breaking them. It will work with 2.4V so I’m think it is one of the newer Nite Ize 2 to 6 cell bulbs. This puts me in an awkward position since it is cheeper to buy this light than a bulb at Home Depot.
That square black part with the contacts pulls out pretty easily. I have changed bulbs in this kind of light several times.
They are designed to be removed and replaced. In any case, as you mention, the lights are cheap to replace.