Jump to content
Survival Threads
KCM

Power Supplies for Cell phones, Night Vision, etc.

Recommended Posts

Wow!  Another useful item that has come way down in price (thanks to pesky "capitalism") are power supplies for small electronics!  You might have seen the little "Liptstick" re-chargers at the checkout counter.  The units all have ratings in milli-amp hours.  Look for "4,000 MAH" or something similar.  You can find the larger capacity ones in the camera department.  The higher the number, the larger the charge.  A 10,000 MAH unit will charge my cell phone twice or power my FLIR Scout thermal hand-held night vision device for hours and hours.  My girls picked up a 4,000 MAH unit on sale at Walmart for $5 the other day.  I was so proud.  Of course, it is pink...

https://www.amazon.com/Hiluckey-10000mAh-Waterproof-Shockproof-Flashlight/dp/B01HZ3NMR2/ref=pd_day0_107_2?_encoding=UTF8&pd_rd_i=B01HZ3NMR2&pd_rd_r=XHT8PTW481D116E1B6RE&pd_rd_w=R7ZUs&pd_rd_wg=llK2k&psc=1&refRID=XHT8PTW481D116E1B6RE

https://www.walmart.com/c/kp/portable-power-banks

 

  • Like 2

Share this post


Link to post
Share on other sites

Yep. The power banks are great and nearly disposable at the price. I've had one of these on my belt for over a year,

https://www.aliexpress.com/item/High-Quality- Battery-Storage-Case-USB-5V-1A-POWER-BANK-Suite-18650-BATTERY-External-DIY-Kit/32773072957.html 

Uses those 18650 salvaged laptop cells , and with a hand selected 2500 mah cell gives my cell phone a full extra day of run time as a wifi hotspot :)  One other nice point is I can pack a few extra cells and multiply the use time. Down side, the internal circuit is drawing a few microamps monitoring the cell , so should get a top off every few months in the pack ( free cells in a plastic box have a storage life measured in years so a second plus for carrying a few extra cells )

I've also got a few of these https://www.aliexpress.com/item/Dual-USB-Power-Bank-6x-18650-External-Backup-Battery-Charger-Box-Case-For-Phone/32805042325.html

Loaded with 6 good cells that's 18,000 mah of storage ( over a week of use on a cell phone ) for $3.15 Canadian. Track record has been solid using 4 for over a year. + side 2 USB outputs, negatives ... once you snap ( ok bash ) the lid closed these do not come apart, also takes about a day to recharge from a standard USB port.  It's a good idea to test and select 6 cells with 2500 mah of measured storage each. In use they are very lightly loaded so should work for years. Airports may take a dim view of these , but at 63 watt hours of storage they are under the 100 watt hour limit for shipping.

I've got a couple of charging projects on the bench , but think those will fit better in the DIY mods thread :) 

  • Like 1

Share this post


Link to post
Share on other sites
12 hours ago, Gary_Gough said:

Yep. The power banks are great and nearly disposable at the price. I've had one of these on my belt for over a year,

https://www.aliexpress.com/item/High-Quality- Battery-Storage-Case-USB-5V-1A-POWER-BANK-Suite-18650-BATTERY-External-DIY-Kit/32773072957.html 

Uses those 18650 salvaged laptop cells , and with a hand selected 2500 mah cell gives my cell phone a full extra day of run time as a wifi hotspot :)  One other nice point is I can pack a few extra cells and multiply the use time. Down side, the internal circuit is drawing a few microamps monitoring the cell , so should get a top off every few months in the pack ( free cells in a plastic box have a storage life measured in years so a second plus for carrying a few extra cells )

I've also got a few of these https://www.aliexpress.com/item/Dual-USB-Power-Bank-6x-18650-External-Backup-Battery-Charger-Box-Case-For-Phone/32805042325.html

Loaded with 6 good cells that's 18,000 mah of storage ( over a week of use on a cell phone ) for $3.15 Canadian. Track record has been solid using 4 for over a year. + side 2 USB outputs, negatives ... once you snap ( ok bash ) the lid closed these do not come apart, also takes about a day to recharge from a standard USB port.  It's a good idea to test and select 6 cells with 2500 mah of measured storage each. In use they are very lightly loaded so should work for years. Airports may take a dim view of these , but at 63 watt hours of storage they are under the 100 watt hour limit for shipping.

I've got a couple of charging projects on the bench , but think those will fit better in the DIY mods thread :) 

Interesting you brought up airports because that was my first thought! I imagine I would get quite the reception if I had this on my carry on. ;) 

Share this post


Link to post
Share on other sites
12 hours ago, Thomas said:

Interesting you brought up airports because that was my first thought! I imagine I would get quite the reception if I had this on my carry on. ;) 

Yeah. In fact any larger Li-ion can start a fire if abused. Most laptops have a 40 to 60 watt hour rating, and if shorted can be producing several hundred watts until something melts, ruptures or burns.

Airport security is largely there to make people think "something is being done" IMHO. The rules display a lack of any rational competence coupled with the old military pattern of getting ready to fight the last war. Air travel was a high profile target, and the old rules were the weak point ( cockpit crew were supposed to negotiate with high jackers having been subject to diverting flights before ). Since hard doors have been installed one, maybe two, loaded planes have gone down because of unstable flight crew members, and the handful of real terrorists have looked for other easy targets, like pedestrians.  In terms of danger, consider how long it takes to pass 1,000 cars and trucks, and consider the odds of .1 % of the driving population being unstable. Every time we drive anywhere we are facing far worse odds then we ever faced flying. But launching a "war" on a tactic sells as a way to justify all sorts of nonsense ( beyond the basic idea being mental in the first place ), and people will agree to anything in the name of safety.

Back on abusing cells. I'm thinking of making a video of fire starting using some Li-ion flat cells I have. One or two using Cat5 cable , paper and a cell, and maybe a couple of just short and film till they self destruct.

  • Like 1

Share this post


Link to post
Share on other sites

I have a extreme. It has 2 usb ports and a flashlight.lithium ion/capacity 10.000mAh 

It'll keep my phone charged 6x longer then normal.I've had the charger for over 2 years now.if i figure right.

Share this post


Link to post
Share on other sites
On 10/1/2017 at 1:49 PM, Gary_Gough said:

Yeah. In fact any larger Li-ion can start a fire if abused. Most laptops have a 40 to 60 watt hour rating, and if shorted can be producing several hundred watts until something melts, ruptures or burns.

Airport security is largely there to make people think "something is being done" IMHO. The rules display a lack of any rational competence coupled with the old military pattern of getting ready to fight the last war. Air travel was a high profile target, and the old rules were the weak point ( cockpit crew were supposed to negotiate with high jackers having been subject to diverting flights before ). Since hard doors have been installed one, maybe two, loaded planes have gone down because of unstable flight crew members, and the handful of real terrorists have looked for other easy targets, like pedestrians.  In terms of danger, consider how long it takes to pass 1,000 cars and trucks, and consider the odds of .1 % of the driving population being unstable. Every time we drive anywhere we are facing far worse odds then we ever faced flying. But launching a "war" on a tactic sells as a way to justify all sorts of nonsense ( beyond the basic idea being mental in the first place ), and people will agree to anything in the name of safety.

Back on abusing cells. I'm thinking of making a video of fire starting using some Li-ion flat cells I have. One or two using Cat5 cable , paper and a cell, and maybe a couple of just short and film till they self destruct.

Out of curiosity, do li-ion cells ever expire/become unstable due to age? I find how volatile they are when opened makes me a smidgen apprehensive. :/ 

Share this post


Link to post
Share on other sites
12 minutes ago, Thomas said:

Out of curiosity, do li-ion cells ever expire/become unstable due to age? I find how volatile they are when opened makes me a smidgen apprehensive. :/ 

Stored at about 2/3 to 3/4 charge I expect the vast majority will outlive me. I have 30 year old cells in fine shape, and they keep getting better. The safeties in laptop packs count the charge cycles and then shut down the pack after a set number. If they were fully cycled it might even make sense, but every drop to 95% and recharge to 99% counts as a cycle, so a "dead" unrechargeable pack with 6, 8 or 9 perfectly good cells. Leaving them totally discharged will destroy them in a few days, reverse charging destroys them right now.

  • Like 1

Share this post


Link to post
Share on other sites
Just now, Gary_Gough said:

Stored at about 2/3 to 3/4 charge I expect the vast majority will outlive me. I have 30 year old cells in fine shape, and they keep getting better. The safeties in laptop packs count the charge cycles and then shut down the pack after a set number. If they were fully cycled it might even make sense, but every drop to 95% and recharge to 99% counts as a cycle, so a "dead" unrechargeable pack with 6, 8 or 9 perfectly good cells. Leaving them totally discharged will destroy them in a few days, reverse charging destroys them right now.

Very interesting, i noticed that the total charge they would hold seemed to wane over time, is it just the imr ones i had? or is that the standard with li-ion?

Share this post


Link to post
Share on other sites
1 minute ago, Thomas said:

Very interesting, i noticed that the total charge they would hold seemed to wane over time, is it just the imr ones i had? or is that the standard with li-ion?

Yes they do drop with use, especially high current use. Salvaging cells, I find new faulty packs ( poor welds etc. ) are often near 2.5 Amp hours per cell. New but very hard use ones can be 1.5 amp hours. Old cells were 1 Amp hour new, and can be down to 600 Ma hours . All still use able just need to match cells to storage needed. They also live much longer if only charged to 3.9 volts as opposed to the usual 4.2 in consumer chargers. that last 0.3 volts doesn't gain much actual storage. Mil spec is 3.9 volts and I'm sure it's a life issue for them too.

Share this post


Link to post
Share on other sites
23 hours ago, Gary_Gough said:

Yes they do drop with use, especially high current use. Salvaging cells, I find new faulty packs ( poor welds etc. ) are often near 2.5 Amp hours per cell. New but very hard use ones can be 1.5 amp hours. Old cells were 1 Amp hour new, and can be down to 600 Ma hours . All still use able just need to match cells to storage needed. They also live much longer if only charged to 3.9 volts as opposed to the usual 4.2 in consumer chargers. that last 0.3 volts doesn't gain much actual storage. Mil spec is 3.9 volts and I'm sure it's a life issue for them too.

Good to know, do you think IMR cells are worth the extra cost relative to the "safety" they offer?

Share this post


Link to post
Share on other sites

"Choose the form of The Destructor!" --- Gozer

Well the IMR cells are more forgiving on a poorly regulated charger, anything over 4.25 volts doesn't add to the charge. But the chemistry also stores less total energy. You can get all those advantages by just dropping the charge voltage to 3.9 volts but pretty well all the chargers are a fixed 4.2 volt output ( kind of like digital watches used to be adjustable , so you could tune them to within a second a week. Now even the traces to add the parts are gone and your accuracy is a matter of chance )

Aside from that the place to control safety is the discharge circuitry. A fuse ( can be as simple as a 30 gauge wire as the + link to each cell ) a thermal monitor to shut things down over 90 C and prevent charging under 4 C .

Any energy storage system is dangerous proportionally to energy density, total volume and speed of release.  A 2 Kg pile of charcoal is fine cooking steaks, drop liquid O2 on it and it's the same amount of total energy but the barbecue will vanish in the flash. 2 Kg of yellow powder heated to detonation and the forensics people may have a hard time finding much to identify. A block of charcoal is a much better store of energy then any battery , but the battery is immediately useful and in small amounts. As we get better batteries with higher density storage, the safety problems change from accidental discharge resulting in dead batteries and maybe leaking cells , to fire and explosion. Most of the problems I've seen have been a result of cutting corners on the final use. So if I am going to spend more it will be on chargers and the extra effort to add fuses and breakers.  

Share this post


Link to post
Share on other sites

Ran into an interesting little unit.   

https://www.aliexpress.com/item/NoEnName-Null-2x18650-Battery-Charger-5V-USB-5200mAh-Power-Bank-Case-Kit-DIY-Box-For-Phone/32807259884.html

It's an unusual circuit in as much as both the micro and "C" USB connectors are directly connected and there is a combination battery charger and power booster chip. So for some UPS applications it's perfect but for a few there is a hidden gotcha. As when it is supplying power the voltage on the connectors is exactly the same as what is there during charging. So while discharging every few seconds it drops the output voltage fractionally. If the voltage doesn't drop a power supply is present and it switches to charge mode. If it does drop then it's providing power and it goes back to a full 5 volt output. Some devices will have problems with that, but for cell phones , flash lights and most electronics it will be fine.

What I find useful is that if you are powering something like a 5 volt cordless phone, or a USB powered WWAN to WIFI hotspot you can just put this inline and most of the time it will sit fully charged and not add any load to the system. It also could float on any 5 volt charging circuit and add capacity. With good cells each pack would be about 10 watt hours of storage.

For instance a 3 volt solar panel into one of these

https://www.amazon.ca/gp/product/B0784SN6H4/ 

( that's 10 for $10.76 ) and adjusted for a 5 volt output. as long as the panel is putting out over 2 volts it will charge the batteries and / or run whatever USB device is attached. 

Those boards can also kick the voltage up to say 13.8 volts and trickle charge a car Lead Acid battery through a cigar lighter , so a battery bank, or solar panel could get a car with a flat battery running in a few hours ( a 5 volt pack would be able to supply about 600 ma at 13.8 volts with one of those, a 12 volt solar panel would be close to 2 amps in good sunlight, but will still do some charging even if partly shaded. )

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×