/diy/ - Do It Yourself

[Anonymous No.723708]

anyone know how to make a powerbank? it can't be rocket science, there are tons of them out there on amazon. I can't find any instructions online though. what has the circuit to be like? I'd really like to make one with a solar panel, I also got some knowledge regarding electronics. is there some sort of charger circuit for li ion you can buy that's powered by 5V (USB) and just hook up to it?

[Anonymous No.723710]

>>723708
http://youtu.be/iC65n2EVQpg

There are tons of tutorials on youtube

[Anonymous No.723711]

yes. ebay.
they cost 2$
5$ for one with a case and everything.
solar is harder. and not really worth it and also stupid. dont leave high capacity batteries in the sun. they dont like this.

[Anonymous No.723714]

>>723710
nope, only shit like this: https://www.youtube.com/watch?v=XDCSDTV0yUo

or some chink company which wants to sell you their charging controler but you can't even ortder it anywhere and if you want you better order 1000 of them because shipping

[Anonymous No.723719]

>>723714
your googlefu is weak.
http://www.ebay.com.au/itm/1x-Nice-5V-Micro-USB-1A-Lithium-Battery-Charging-Board-Charger-Module-Protection-/181557677953?pt=AU_B_I_Electrical_Test_Equipment&hash=item2a45ae4f81

$1.74 incl shipping

[Anonymous No.723721]

>>723708
just balance however many cells you want and then wire them in parallel.

[Anonymous No.723722]

>>723719
>1A
fucking cheap shit, I need MOAR AMPS
the USB limit is 1.5A. why not just make it 1.5

[Anonymous No.723723]

>>723722
1A charging. 3A output.
if you need faster charging then get a imax b6 charger, a lipo pack and a 5a ubec from hobbyking.com.

[Julez No.723730]

I know how to make one.

First, you need a shitload of cells. I slaughtered some LaptopPacks from ebay and have now around 40 good cells. But I am an RC Geek and have all kinds of computerized chargers to test cells. If you don't have this, buy new name-brand cells, ie avoid everything with "fire" in the name.
Second you need a charge circuit, precisely this:

http://www.ebay.com.au/itm/DC-DC-Converter-CCCV-Power-Module-LM2577-LM2596-Charger-Module-/121409411294?pt=LH_DefaultDomain_0&hash=item1c449098de

You can power it with a large variety of input voltages, meaning solar is also acceptable.

Third, you need a Converter to make the USB-typical 5V from it.

http://www.ebay.com.au/itm/2PCS-PFM-Control-DC-DC-USB-0-9V-5V-to-5V-dc-Boost-Step-up-Power-Supply-Modul-M29-/291156172199?pt=LH_DefaultDomain_0&hash=item43ca429da7

Problem is, they work down to 0.9V, so they might deep-discharge your cells.
To prevent this, put a protection circuit between the cell pack and the USB thing:

http://www.ebay.com.au/itm/5pcs-1S-Li-ion-Lithium-18650-Battery-Input-Ouput-Protection-Board-PCB-DW01-/181441124951?pt=LH_DefaultDomain_0&hash=item2a3ebbda57

One of these will do.

I decided it is not worth the hassle and bought this one from Fasttech:

http://lygte-info.dk/review/Review%20USB%20battery%20box%206x18650%20Qidian%20UK.html

Search theyr power bank secion, they have an identical thing there, but matte black, not shiny. Works very well.

[Anonymous No.723808]

A powerbank with LCD display telling you percentaage would be cool

I got a QI powerbank from lugulake, 6Ah and you can charge wireless with qi or with USB. it has a 4 LED power indicator but it's inaccurate as fuck. when only 2 LEDs remain the thing is empty in 5 minutes.

[Anonymous No.723815]

Dumping the schematics and PCB for a solar powered lighting installation I did a few years ago.

[Anonymous No.723816]

>>723815

[Anonymous No.723817]

>>723816

[Anonymous No.723825]

>>723817
that looks pretty cool, where is that at?

[Anonymous No.723831]

>>723825
It's set up near Vancouver. A random spot along the highway nobody ever walks through. I didn't get any say in the location.

[Anonymous No.723857]

I actually have a question along the same lines.
Looking into building an electric bike.
I had my eye on this kit here:
http://www.ebay.co.uk/itm/Electric-Bicycle-E-Bike-Conversion-Kit-48V-1000W-Brushless-Motor-Rear-Wheel-/170939207305?pt=UK_Bikes_GL&hash=item27ccc54e89..
It doesn't include a battery though and after looking around on forums and a bunch of different ebike retail sites as well as ebay I found that batteries are expensive as fuck.

Anyway, my question is can I build my own battery like this
(http://www.ebay.co.uk/itm/2014-Model-48V-10-4ah-bottle-holdermount-lithium-Li-ion-electric-bike-battery-/171524013964?))
one using four of these?
(http://www.ebay.co.uk/itm/DC-12V-6800mAh-Super-Rechargeable-Lithium-ion-Battery-ON-OFF-Switch-OVS-SCA-0650-/171327297905?pt=UK_ConsumerElectronics_Batteries_SM&hash=item27e3e71971))
The massive price difference makes me think I can't, I know very little about electronics though so I really have no clue.

[Anonymous No.723861]

>>723857
I can't find any information about how much current the battery you posted can output. the problem is that you need like alot of current to drive the bike.

[Anonymous No.723865]

>>723861
So do you think I'd be able to pull it off using some sort of step up transformer?

[Anonymous No.723872]

>>723857
A 1000 W motor at 48 V, will draw somewhere between 20 and 30 A when you step on it. A really rough rule of thumb when dealing with batteries, is that you don't want to discharge them at more than 1C; i.e, 1 ampere per ampere-hour. Some can handle a lot more, some can handle less, but unless you have a real datasheet for your batteries (which you don't get for $20 packs off of Ebay), I wouldn't use anything smaller than a 20 Ah battery for that motor.

[Anonymous No.723876]

>>723872
Thanks anon.

[Anonymous No.723885]

I want something that can supplement my computer battery. is it out of the question to have a giant ass battery and then plug that into a 12v DC to 120V AC inverter you get for a car jack, and then plug the computer charger into the inverter, and use to charge the computer battery, and the computer thinks its plugged into a wall outlet and doesnt know the differece?

Not worried about efficiancy, just the concept.

[Anonymous No.723905]

>>723885
The concept is fucking retarded, though it will work why wouldn't it?

Does anyone know that video of the dude who made a handheld AC generator making 120 (or 230 not sure) V AC from batteries? It had some sort of spinning thing which made the Ac

[Anonymous No.723912]

>>723815
>>723816
That's nice but I think it would be more useful if you'd post the binary for the PIC somewhere.

[Anonymous No.723939]

>>723885
At full charge 3.7v batteries are really 4.2v and drop to 3.2 at empty. 3 in series would give you between 13.6v and 9.6v. The best high drain batteries you'll find in stock are 2100mah. You'll want 15 parallel series to get 31.5ah. So 45 batteries. That'll run you $400 - $500.

Can you do it? Yes. Would I want to be in the same city block as you charge it? No.

Get a car battery.

[Anonymous No.723959]

>>723857
http://www.pingbattery.com/servlet/the-12/48V-15AH-V2.5-LiFePO4/Detail

533$us

this is about as cheap as you can get. the batteries are the most expensive part.

beware the cheap small packs that claim amazing capacity. they suck.

[Anonymous No.723965]

>>723959
like this thing. they go for like 6km before running out. there's just no way you can fit the rated capacities they claim in those small packs. there's a physical limit on the size of batteries with the current technology.

[Anonymous No.724074]

>1kW
Nagga you need more power

http://youtu.be/_ZpIYw_Xs_E

[Anonymous No.724081]

>>724074
what's the point. you can't drive it anywhere. its such a clear road rule violation

[Anonymous No.724227]

>>724081
Then make a normal looking e bike but with powerful engine. There are several videos out there of people riding e bikes in traffic and smoking cars

[Anonymous No.724240]

If you must use solar, have a panel that connects to your pack. Don't mount cells directly on the powerbank for 2 reasons:
1) Cells on the bank are pitifully small and will probably only output about 400-500mW of power after conversions and losses.
2) Direct sunlight exposure without good a good case will heat up your batteries, shortening their lifespan or worse.

Anyway here's the basic procedure.
1) Hit up ebay/aliexpress for 3-6 Ah lithium cells, get the rectangular ones not the cylindrical batteries, watch out for ludicrously high capacity rating scams.
2) Connect them in parallel.
3) Research lithium battery balancing and see if you need it, iirc you don't when they're in parallel.
4) Attach a 5V boost converter and a charging module, both from ebay for a few $$$ each. Make sure the boost converter can supply 1A, or 2.1 if you have an iPad iirc.
5) You're done, you should have bought about 15-20Ah worth, which will charge your phone probably 5-10 times over.

[Anonymous No.724317]

Any chance to put a display in there that tells you the battery percentage? There must be some chips which do this, right? Phones can do it too after all.

Apperently there are powerbanks on amazon that show you the percentage and they aren't even that expensive but they're very thick

[Anonymous No.724348]

I would bet my left nut that quoted capacity is a single cell at 3.3 volts or so getting converted up.

this autismo did it
Batteries will always cost alot
https://www.youtube.com/watch?v=Z-VLdE6RxYQ

[Anonymous No.724710]

Where can you get flat cells like this one?

[Anonymous No.724733]

>>724710
Hobbyking 1s lipos

[Anonymous No.724737]

>>724733
Lel

[Anonymous No.724739]

>>724733
Nogga it's a 6Ah li-ion. it's thinner than those cheap tube batteries

[Anonymous No.725268]

>>723708
Dude I had the same issue as you. But now I am enlighted. Solution to all the below problems: http://m.ebay.com/itm/181508204888?txnId=1257295344008
May Tyrone bless u.

[Anonymous No.725280]

>>725268
>18650 cells
shit is too thick dood. need some flat shit

>>724710
i need this battery man, sell it to me

[Anonymous No.725283]

>flat li ion batteries

guys, can you just take a smartphone battery and drain current from it? or does it have electronics which don't simply allow this? The smartphone batteries I'm talking about have 4 pins and 2 of those seem to be for communication to the battery/temperature. or can you just hook something up to + and - and charge the battery through that?

[Anonymous No.725286]

>imax B6 charger

can't you charge lithium ion batteries by just hooking them up to a lab power supply, setting it to 4.2V (or whatever the cells maximum is) and limiting the current?

[Anonymous No.725363]

>>725283
crack it open and bypass the brain, sure, it's just a battery then

[Anonymous No.725612]

>>725363
I'm afraid that I might cause a fire or something, it seems pretty well sealed. Is the battery inside the battery case also properly sealed against humidity and such or does the case which I'd tear down do that job alread??