Varta 18682 reflector flashlight dead battery to 18650 - Page 1
Forum section: electronics / repair

author: Johniee
author_rank: Newbie
timestamp: April 05, 2023, 08:29:11 am
content: Hello guys!I got a Varta 18682 reflector flashlightLinkwithout charger.The Lead-acid battery was totally dead and heavy, so I want to upgrade the whole thing to 4 or 6pcs 18650 cells.The original PCB is burnt, the LED is working, it needs 7-800mA.I've ordered a 10A 1S BMS module for the cells from Aliexpress.What do you think, which option is better to charge the parallel 18650 cells?4,2V 5A Lithium charger from Aliexpress or XL4015 DC CC CV Lithium Battery Step down Charging Board with my 12V 4A power supply?I appreciate any smart ideas

author: Swainster
author_rank: Frequent Contributor
timestamp: April 05, 2023, 10:27:24 am
content: Perhaps use a USB C power bank control board? That way you could add some extra functionality to your flashlight, although I guess that the overall charge time will be longer.You can get some pointers from this Great Scott! video:https://youtu.be/yEbbhTw0kno

author: tunk
author_rank: Super Contributor
timestamp: April 05, 2023, 09:31:27 pm
content: Li-ion cells should be charged with CC/CV/cutoff.An XL4015 DC CC CV won't do cut off. Member HKJ has tested 3-4 2Schargers, none of them does cut-off, most also overcharge the cells:https://lygte-info.dk/info/indexBatteriesAndChargers%20UK.htmlI think I would use slower charging with a TP4056 module.

author: thm_w
author_rank: Super Contributor
timestamp: April 05, 2023, 10:10:20 pm
content: Life will be easier if you parallel them as 1S and use a TP4056 USBC module as recommended by tunk.The only issue is the long charge time, around 1.2A. So if you have 4x 3Ah cells, would take about 12hrs to charge.There is also the TP5100 module:https://www.aliexpress.us/item/3256804151444891.htmlFor 1S or 2S. Would handle 12V input. Or maybe the powerbank board mentioned above (if they sell just the board), although I don't have experience with those.

author: Johniee
author_rank: Newbie
timestamp: April 06, 2023, 09:52:55 am
content: Thank you guys!I've ordered the PowerBank module which is from Great Scott recommended!I also have a PCB board module with 5V 2A charging, this onehttps://www.aliexpress.com/item/1005004118389586.htmlI also was thinking about more TP4056 modules, for each 18650 cells 1 of them

author: Johniee
author_rank: Newbie
timestamp: April 06, 2023, 12:27:04 pm
content: I've made a schematic for this project.Do you agree is this a good conception or should I use a plus 3pin rocker switch at the grey(-) output from the PowerBank module?Then I could choose between thecharging vs LEDis working modes?orcould it charge the batteries and turn on the LED light at the same time? Can I use this way?There is that red original switch to turn ON/OFF the LED lightThe LED needs the 1S battery voltage

author: thm_w
author_rank: Super Contributor
timestamp: April 06, 2023, 09:53:35 pm
content: You want the switch on the positive power input to your LED driver, after the battery. So what you've drawn looks right.Some lights prevent turning them on during charging, but, I see no reason why that matters here.

author: abdulbadii
author_rank: Frequent Contributor
timestamp: April 07, 2023, 12:02:06 am
content: what original PCB function, schematic ?Imho get such bumped + pole Li-ions along with their quality charger eg. NITECORE New i4, Xtar etc, which'd estimate their capacityImho this kind charger is not linear, can do constant current, that is when all clear open DCV MM probe will read 0/low V while a Li-ion being charged will read a V slightly above currently its V

author: Johniee
author_rank: Newbie
timestamp: April 21, 2023, 09:02:34 pm
content: Hi everybody!Thanks for the previous helps! I've made the Flashlight ready to go4pcs 18650 cells installed inside with the PowerBank module.It works well with a AMC7135 LED driver on 700mA with the 1S battery cells.+ installed and hot glued battery level indicatorAs you can see, the result at the back not beautiful at allDo you think could I fill the gaps nicely around the USB plugs with inserted Dust plugs and with hot glue stick(s) + a kind of masking??Or what should I do? This is not rain proof this wayI didn't find similar successful project on Youtube with hot glue.

author: thm_w
author_rank: Super Contributor
timestamp: April 21, 2023, 10:38:30 pm
content: Ideally you'd start by just cutting out the area you need, but thats hard without a milling machine.Black RTV silicone could work.Black hot glue would fill up the gaps as well if you just want it to look better.But it the silicone won't be waterproof unless you pour a bunch on the inside to seal the backs of the connectors.