As was discussed in the Q8 thread, adding a lantern attachment to the Q8 should be pretty simple, just a matter of getting the reflector angles right.
Adding a charging circuit on the other hand would be a much larger issue, it would require a new driver and most likely a redesign of the body itself, at least to some degree, at the very least for the USB port itself.
Although charging a Q8 should really be done with a USB type C connection to get any kind of worthwhile charge times, this would need the cells to be in 4S to work effectively though but it would allow for 10X faster charge rates.
You could possible add a charging circuit to the tail section of the Q8, with an extended tailcap, although charge times would be VERY long indeed. Talking ~10 hours for a full charge.
What? Put the cells in 4S to charge? That’s the worst possible way to charge Li-Ion cells! Where did you get the idea that the charger circuit “would need the cells to be in 4S to work effectively”?
Im my opinion, despite all discussion, a lantern should have a downward facing light source, like DBSAR’s prototype. You can add a sideways pointing reflector on top of the Q8, but will then still need very heavy diffusing to prevent looking directly into the leds.
Lanterns should project light sideways and downward, and only little light should go upwards.
I said that it would be faster to charge in 4S, not better. The light would also work better in 4S.
It is very simple why, a USB type C connection can provide up to 100W of power but it can only do that at 20V out output. Thus a 4S would be about perfect at 16.8V.
In 5V mode any USB is limited to around 10 watts.
At 10W (aka, 1,8A) the cells will take about 10-12 hours to charge. Compared to around 2 hours at 100W
Charging in parallel is better long term for sure but it is also MUCH slower.
In order to safely charge a 4S arrangement, you’d need cell balancing, which means a “battery pack” is going to be the only way that makes sense. Randomly throwing in 4 cells and charging them in series is dangerous, and even more so when considering “Fast Charge” capability. Manufacturers can’t afford to leave such an important safety consideration for their customers to figure out. Parallel charging is fast enough, much simpler, and much safer. It isn’t likely anyone will ever find themselves needing a full charge on all 4 cells, and that in a short period of time. If the light needed to be used soon, an incomplete charge would likely suffice, with a full charge left for a more convenient time.
Would anybody else like to see this lantern with grey anodizing or some color such as blue or green? Maybe it’s just me, but I always find black to be an off-putting color for a lantern. Probably one of the least important aspects of this project, though!
If the lantern gets onboard charging it should be possible to use while charging and to use it without any batteries in it. So it might be possible (depending on the cell config) to run it from a powerbank or something.
For the Q8 lantern thing, I would just go for a diffuser type of thing. Whenever I use a FL as a lantern I try to hang it up side down above my head, that way all light is projected downward and none is lost.
Yeah for sure. Thinking about it though, charging at around 3 to 4A (if 4cells are used in parallel) and running the lantern full throttle could cause for some serious heat building up. But since it’s it not a tube light I believe this can be avoided by way of design. Something that would not be possible with the Q8 for example.
Edit: Instead of using micro usb charging, charging like an olight or the way convoy does would definitely be a step up from al the other light using micro usb.
I have ran the Lantern prototype on maximun mode for 7 + hours continuous with no problems. as the LED emitter is located at the top, The lantern head is the heat-sink, meaning all the heat is kept away & rises up & away from the battery tube and driver areas.
It would be a nice looking feature, but microUSB has the practical aspect in the field use. Chance to find a common microUSB cable if one get lost is higer than getting an proprietary charge adapter.
For long-term use it could even be helpful to add an USB c-type plug (additionally to microUSB maybe).
I should read the whole threat :person_facepalming: . but that’s great, so charging and running the light should pose no problem.
About usb plug charging. I still think there are better options, specially because it’s a lantern the designer(s) is/are less restricted with space. Maybe the charging cable could be stored secured in/on the lantern. And for long term usage I think it’s better to avoid ubs plugs in the lantern. Check the forum and see how many negative comments there are on usb charging. The convoy or olight way also allows for better water proofing then some silicone thingy over the usb input.
But before all this can be discussed it is needed to know the cell configuration. If it’s 4S or 2S2P usb charging is out of the question I believe.
This prototype is 4P configuration, so charging the four cells is safe. I prefer 4P config as the lantern can be run on 1, 2, 3 or 4 cells, is safer, etc. I have tested a TP4056 1A USB charger on 4P 18650 cells and they charge no problem during the day. ( also charging the cells at 250ma each when in 4P series the cells don’t heat up, and last longer over time. A TP charger board can charge the light while its still running, (with light on medium or lower modes so the charger can output more power than is being drawn to both charge cells and power the driver, also that would basically run the light from the USB charger effectively, as once the cells reached full charge the charger would sort of ” float” charge the cells & run the lantern. meaning it can be run from a 12 volt USB adapter, wall USB adapter, etc.
I don’t really understand. So if you run the light while charging, it still charges the cells at 1A AND runs the light. So it’s putting out like 2 or 3 Amps? Or is it drawing the current from the cells that are being charged?
I find 250mA really low takes like more than 12h to charge. Wouldn’t get away with 500mA ,don’t think it woud heat up the batteries that much but he charging board might get hotter?
Don’t know much about electronics but I think I’d rather see the cells disconnected (electronically) from the driver while charging and that the light is run straight from the input. That way the light is able to run without batteries in it. I don’t even know if that is possible at all but that’s what’s inside my head.
I added bold to the important bit above. The charger is supplying 1 Amp to the batteries, split equally between the four batteries installed so they each get 250 ma. As long as the LED is drawing less than the charger is putting in (1 Amp in this case) the batteries are being charged. So assuming that nothing is lost to inefficiency, the formula is:
(I (charger) - I (LED)) / (# of batts) = I (battery)
sort of like a pewter/titanium anodizing color.