I am working in a 50cal ammo can battery pack to charge phones and other stuff when away.  The original plan was to just use a small deep cycle battery.  However the 18650 batteries look like a better option if I can get them for about 2$ apiece on that auction site.  I can fit a lot of 18650’s in an ammo can and get ~13.2V to 14.8V.

What batteries did you use?
What kind of PCB set up did you use?
Is there a charger controller that will charge from 120Vac and DC (solar) (I have ~17Vdc available)?
Any advice?

That looks sweet.. I have probably 50 3400 ma batteries in cold storage,, plus a few users.. that looks like a good future project.

Going 18650s, you don't want to buy crap cells, or laptop pulls, or cells that have been stored incorrectly (full/high/low temps,) so $2 a cell is a bit spotty.  For $5 a cell, you can get the newish 3400mAh Panasonic NCR18650Bs, which have been at the top of the heap for 2-3 years, although they aren't >10A drain, that shouldn't be a problem for your setup.

If you want 10A cells, but still almost as high in capacity, you might try the Samsung 30Q, the LG MJ1s and/or the Sanyo-Panasonic NCR18650GAs, but those will probably be over $5 in say quantities of 20+?

If you go 3S8P: 3 in series, 8 strings in parallel, that'll be 24 total cells.  They come hot off the charger at 4.2v and are 3.6-3.7v nominal, so we're looking at 10.8v (nom.) to 12.6v.  Throw in another in series and you're at 14.4v-16.8v and then capacity will be 3400mAh x 8, or approximately 27Ah.

You can play with the numbers and amounts.

You'll need a balancing charger, since you're charging in strings and that implementation is probably a bit above my pay grade, but guys build 50 cell packs for electric bikes everyday, so it's being done and done safely.

This guy might be able to help you, if you PM him:

http://www.candlepowerforums.com/vb/list.php?author/10167-Overclocker

Here are a couple of good places for li-ion cells:

https://www.imrbatteries.com/

http://liionwholesale.com/

There are E-bike sites out there, as well and building packs and charging solutions are their speciality.

Chris

All of mine, except for maybe half of my users, are Panasonics... at $10 each,, it put a hurt on my wallet,, but I collect flashlights,, bright flashlights,, I have one that I can use extensions, and install 12 of these for long runtime..

Ahhh, yes,, Candlepower.. I am a member there, but haven't been online if probably a couple years.. started hanging out at budget light forums..  I need to long on an check out new stuff... thanks

Yeah, the OP's info is out there, I'm just not somebody to school you on building multi-cell packs with charging algorithms, is all.

A little research will give you both all the info you need.  Tabbed cells will be helpful and there are places that sell them, so that's not a problem.

My reply was mostly a caveat on not buying the cheapest cells that you can find, but to start with quality cells and a safe way to charge them up in series, which one will be doing.

Chris

I personally would not build a pack. Too many things can go wrong and balancing all those cells is tough.

For your build I'd run something like this for $100.00.



https://www.amazon.com/Battery-Tender-BTL14A240C-Lithium-Phosphate/dp/B00F9LPJ8S

May I suggest Military BB2590s. There is some cost up front sourcing a good charger but they can't be beat. The only issue is they run about 16 volts. I bought some Battaxx adapter plugs and made a plug in down converter using a switching converter. They are rugged as hell and last forever. The converter is adjustable from about 6v to 30v and has a secondary fixed 3 amp 5 volt switching supply that feeds the USB port for phones or whatever else. I've used it all week and the batter has only dropped about about .5 volts. I can plug the ecig in and smoke till I pass out.

http://www.battaxx.com/product/bb590-male-connector



About 12 Ah of power

Thanks guys.  The cheep batteries all look fake.  To bulid with Li batteries is getting too complicated when i add in a DC to DC board to handle solar charging.

I am going with the original plan and will get a UB12150 SLA battery.

I will still have 15Ah @12V

I went out and bought a Chrome 22Ah and a PowerSonic 12Ah AGM battery to be used with a 12v Triplett inverter, my 2x30w solar panels and Morningstar SS10L controller, for emergencies.  I don't need it to be light in weight, but I can't charge up various batteries/cells, run a 12v fan and some other small devices during hurricane season.

Chris

What auction site are you refering to?

go Li-po. plenty of big cells out there with plenty of amps to power pretty much anything you want at a lower weight than a SLA or gell cell battery. then you can use a standard Li-po charger and not have to worry about any special charging setup.

That big bay site.  Don't bother the general consensus is they are fake.

I finished the ammo can battery pack.  It works good enough for my needs.  It charged my phone for a week.  Here are the details:

Can I ask where you purchased the panel on the side of the ammo can?

Sure

http://www.amazon.com/Alwayswish-Charger-Voltmeter-12V-24V-Motorbike/dp/B015LYG7TW/ref=sr_1_1?ie=UTF8&qid=1473540068&sr=8-1&keywords=Alwayswish+4+hole+Pane+Base+kit+With+Dual+USB+Charger+%2B+DC+Voltmeter+Meter+%2B+Power+Socket+%2B+ON-OFF+Button

 

SurvivalTech Nord on YouTube has some videos on building your own 18650-based battery pack.

Here is the corresponding US link

https://www.amazon.com/Alwayswish-Charger-Voltmeter-12V-24V-Motorbike/dp/B015LYG7TW

His soft voice makes me think of him as the Bob Ross of Ham radio videos .......

 



Lets put a happy little QRP antenna right here .

 

Balancing a bunch of cells becomes a lot easier when they're all connected in series - which is what most manufacturers of cordless tools are doing.

Currently, they're getting 80+ volts out of 'em...

...which begs the question: How do you convert that high voltage down to 12VDC without wasting a lot of power, or generating a lot of EMI?

In other words, how do you make an 80 volt, 3,000 mAH battery pack look exactly like a 12 volt, 20,000 mAH battery pack?