Be careful…
@Hoop is replying… right now… L☻L !
It’s not what you asked for and it’s somewhat involved, but I would build a sconce, or even a couple of them, that bounces light off of the ceiling, if the ceiling in this bathroom lends itself to that. This lighting approach helps to reduce glare. If it is being built from scratch any battery format could be used, and any LEDs could be used, such as Nichia 519A 2700k 9080. They would be mounted to the wall above eye level.
Short of building fixtures from scratch, the same approach can be taken by using multiple large format flashlights with good battery capacity, such as Convoy 3X21A SST40, but in the case of the 3X21A SST40, I would contact convoy and see if they would build them using Nichia 519A 2700k or 3000k for me, and if not, I’d swap those LEDs in. Wall brackets could be 3d printed, or the lights hung from existing fixtures or to eye screws etc. using wire or twine or whatever, to get them above eye level.
Three 21700 cells only offer ~14 Amp hours of useful capacity, so you’d need to run each light at a ~500mA load to achieve 25 hours run time, which would provide ~200 lumens with the Nichia 519A LEDs. Multiple lights would be needed to achieve higher output.
So you see, you need quite a large battery pack to do what you want, something along the lines of 50Ah+ capacity. A large prismatic LiFePO4 cell would be an easy and safe way to achieve this. An example of a good one is “EVE 3.2V 80Ah Prismatic LiFePO4 cell” which is only $40 to $50. But you do need a hobby charger to charge this, or dedicated 1s LiFePO4 charger. An good inexpensive RC hobby charger is the iMAX B6AC V2, although it is limited to a 6Ah charge rate, which would take 12+ hours to charge an 80Ah cell. A more powerful RC hobby charger would do it faster, and I see some around $60 that can provide 10A charge rates.
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I am sorry for my stupid question, if I change the cells to increase the autonomy, can it catch fire ? Is there any danger if I switch to 3500 mAh ?
what type of batteries do you recommend? a particular brand?
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Very good question !
I don’t believe that will be any problem, except that probably will be more hot… (but don’t forget that you are asking for some very special - specific use…!?) !
I prefer to run my flashlights with recommended batteries from the same brand… yeah probably they don’t make them and they are more expensive… but i like this way so that i know that im using the right ones, and the ones that they made the test with… ! Again, is just my opinion and how i like to run and treat my gear… !
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I was just joking around !
Hoop is very good, and has more knowledge and experience from me… !
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Last I knew, the Sofirn cells that come with the LT1 were okay, 3000mah is not bad capacity, max available is about 3500mah.
This thread will help you if you want to buydifferent cells. It’s important to get them from a trust worthy supplier. The LT1 needs “button tops”.
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The LT1 can be ordered with a set of 3000 mAh cells. They are nothing special, but they are not bad either.
If you want 16% more runtime, you could get a set of four Samsung 35E 18650 cells with button tops.
To ensure there are no fires, measure the voltage of each cell with a multimeter. Make sure they have the same voltage, at least within 0.05V of each other. Then put them into the light, with the “-” end on the springs and the “+” end up. Close the lantern. Afterward, treat them as a married set, and charge them by plugging the lantern in to USB.
Or just use the cells Sofirn ships with the light. They’re pretty decent.
If your room has a white ceiling though, it may be more effective to use a traditional flashlight instead, and shine it at the ceiling. This distributes light more evenly, and reduces glare, so it’s easier on the eyes. And, of course, if you need to see something up close in detail, move or aim the light to point at what you are doing.
The traditional forward-facing light which most closely matches the LT1 is called a Q8. Some versions of it have built-in charging. However, it has a much much brighter high mode, so you would need to run it much closer to the bottom of its range if you want it to last 25 hours.
Another option is to use a smaller light at a lower brightness level, and simply aim it at what you want to see. This gets the same runtime and the same or better visibility, for a lower cost. Some “angle lights” can even be clipped on and worn as clothing, to see in front of you no matter where you are.
This curated list shows what’s good at the moment.
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The higher capacity cells will not cause the light to catch fire. They will allow longer run time (you use the word autonomy?). At the highest level (often called Turbo) there “might” be a “slightly” higher temperature in the lantern , but only for a short time. None of the lanterns that I have (at least 10) get hot at all, regardless of the batteries I use. Even this will not always be true though. Any additional heat would be caused only if the cells could supply more current than the original cells on the maximum output (which you will not be using to get the hours of light that you want… Most of the time the higher MAH (capacity over time) cells actually have higher internal resistance and will supply less maximum current in a specific application. For lanterns, in general, it will make no difference at all in heat as they are not designed to maximize current draw, and hence will just not get very much hotter, if any, even if you were to use a cell that could supply higher current. At low levels the light will not see any increase in heat.
In short, going from 3000 mAh cells to 3500 mAh will do nothing but give you longer light output at a given level. Nothing to worry about at all! Also, in this case, as long as you get good name brand cells from a reputable supplier, the differences from one brand to another will make little difference.
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Yes If using one or more lanterns, I like to hang them up above eye level so that you do not have to look directly at them when going about your business. This is the same idea that is used when we mount lights (AC) on the ceiling or in fixtures on a wall above eye level. Ideally, in a corner where reflection form the walls and ceiling help distribute the light more evenly.
Ceiling bounce with a flashlight is effective as long as you can mount the flashlight where it is stable and secure and not located where it will be bumped into and knocked over.
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which means you are not allowed to press a button to turn on a flashlight, nor to push a button to change lantern output, also not allowed to change batteries… not allowed to light a candle after sunset on Friday… etc
if your Rabbi agrees with this link:: you could use an electric light if you turn it on before the start of shabbos:
“In general, from an Orthodox perspective, it is permissible to benefit from most electrical objects during Shabbat, provided they are preset before the start of Shabbat, and the status of the appliance is not manually modified during Shabbat. These include lights, heating, and air conditioning.”
So, I think an extension cord to power a light in the bathroom might be OK… (ask your Rabbi)
How do you light the bathroom on the other 6 days a week?
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The other 6 days he is not restricted and can use/operate a light. IT is acceptable to turn lights before and keep them on entire Shabbat assuming there is one. (which is exactly what he wants to do, turn it on before and keep it on entire Shabbat). Or maybe that bathroom is only used for Shabbat, we do not know, nor we should really care.
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If I understand correctly, which is a big “if”, the restriction on turning lights on/off stems from a rule forbidding people from building or extinguishing a fire. The idea is to not work for a day, to spend that day on worship and pleasure, enjoying and appreciating life. Building or cleaning up a fire is a chore which requires a significant amount of effort, so it’s considered work and thus forbidden. Just saying “no work” is pretty vague though, so there is a list of dozens of specific types of work people are not allowed to do.
Over the millennia, this has been reinterpreted many times, and the interpretation varies greatly from one group of people to another. In some, it is interpreted as forbidding things which resemble tasks that required a lot of effort in the past, but aren’t really work any more. Like, setting up and tearing down a fire is kind of a pain… but flipping a light switch is not. However, both involve (de)activating a source of light, which is similar enough to “count”, depending on which interpretation is used. In a traditional wall-mounted light switch in particular, there could occasionally be a tiny spark for, like, a millisecond, right before the switch closes… and a spark is kind of like fire… so it is sometimes forbidden on that basis.
However, people are often permitted to just turn a light on beforehand, and leave it on until 25 hours later. It’s not the fire itself which is forbidden, but the effort of building and extinguishing one. So people can just leave one on the entire time as long as it doesn’t take any work. And to change the brightness, people are allowed to draw a shade in front of the light to block some or all of it. Some Shabbos lights are built specifically for this, so you just turn a knob or slide a lever to move a shade or something which adjusts brightness. In a similar manner, I’m guessing people would probably also be allowed to turn a dial or touch a touch sensor to adjust the intensity of the light source, since that’s less effort than drawing a shade. Many recent lanterns and flashlights have this type of thing built in too, like smooth ramping to adjust brightness. No need to turn it on and off; just dial it brighter when you need it, and dimmer the rest of the time.
The main thing, though, is that avoiding work should not take more effort than the work itself. If it does, that defeats the point.
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But knowing the entire situation would impact recommendations. So while, in the big picture, I don’t care. Knowing the whole situation really helps me in figuring out what I would do to solve the problem.
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But you are applying logic to religious customs. Which often fails as these are based on faith.
I wonder why the OP decided to explore battery operated devices as a solution rather than doing something more traditional.
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It would?? i do not see how, his religion practices and traditions are irrelevant as far as our recommendations, he asked for a light that will run nonstop 25+ hours. that is what we need to focus on. It would be helpful to know the size of the room and color of the celling. cuz if ceiling is white then a celling bounce would work, if it is a cabin type of outdoor bathroom with wooden planks and plywood as a ceiling, then not so much. How he goes to the bathroom the rest of the week, or why he can not touch the light or replace batteries, or use a sensor is really not gonna help us make a recommendation at all.
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Yes, the why is not important, but knowing what he can and cannot do is. Some of the things I posted about may not work for him depending on what is acceptable. No judgment from me, but like in anything, understanding the requirements is essential to formulating a solution.
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The place is white and about 35 feet
White ceiling is helpful, when you point a flashlight up, white ceiling acts as a reflector and lights up entire room more or less evenly, a lantern on the floor will not have such effect. when you say 35 feet is it a ceiling height, or square footage of the room? cuz if it is height, you will need at least 1000 lumens. A light that will run at 1000lm for 25 hours straight, needs to be a light that is capable of much more, so 1000lm is its low mode, and it has to have a large battery. If 35 feet is a square footage than a less powerful light will do, i’m thinking around 300lm will do, you can get away with a less powerful light. you do nto need to worry much about beam pattern (as in throwers or flooders) cuz when pointed at the ceiling it makes little difference, as far as room illumination,
It is hard for me to tell you exact model, cuz i’m do not buy many lights, i’m into building light not so much buying, new ones come out few times a year, there are dozens of manufacturers, fortunately there are people here that follow the “trend” and can point you to exact model. but whatever it is it has to make enough light in low mode and it probably wont be cheap, such light s are usually in 200-400 range.
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35 feet in what dimension? Height, Width, Length?
Whit is good… 
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sorry 35 feet is the restroom size