I made this awesome DIY battery power bank! I use it for my LED outdoor type lights. (WHITE&BLACK)

It is a power source so of course it can be used for ANYTHING like powering a portable radio or charging a phone or tablet. And of course you can charge from a laptop power supply to a 12V solar cell!

Basically it's the same thing as a Milwaukee Tool battery.

NOT WATERPROOF!!!!! IF IN THE RAIN BAG IT!!!!!! OR HIDE UNDER COAT?!!!

(My lights have an IP rating THIS WON'T!)

Supplies

(16) 18650 batteries

Nickle plate strip for battery welding

4S BMS Anything > 15A the lower ones never work and have to throw out.

(2) XT 30 connectors Male "I personally use male side for power side"

push button

Mini DC LED Panel Voltmeter 3- digital display

Wire, solder, electrical tape, hardware(4)

Step 1: 3D Printing

Files can be found

HERE

Step 2: Spot Welding

Spot weld batteries in place and tape up. I've heard that you start with "parallel" first. Then work your voltages up. SO that does seem to work. I don't think it's much of a difference as long as the voltages are good. I have had bad cells that started to blow up! Be close to outside for disposal if case safety measures! Which is why I have my setup for this in my garage! (DIY MOT) This is where the actual DANGER exists!

ALL batteries MUST be within .1 variance! Else set aside. It's best to just have all batteries fully charged off charger!

Make sure each weld hold up with a small screwdriver. Poke around. This can be Extremely tedious and annoying! Good Luck! Measure around with voltmeter to make sure your good for next step.

Step 3: Assembly

Solder the BMS right on top of the battery bank.

Since you have a Input/Output you need to splice and double it up.

Solder the voltmeter directly on the split.

Push to test! (Usually these things are off. Use a "FLUKE" to know true) Mine was .2 off. and had another at .4 off.

Use UV super glue to hold in place the XT connectors.

Finally these are meant to be slightly over filled box. So you can stuff foam inside for a nice tight fit!!! RECYCLE FOAM!

Step 4: Test and Charging

Test as shown.

I use an old power 19V from laptop power supply and cut wire replace with XT connector.

I would share the "buck converter" dc-dc step converter but too many FAILS!!!! HARD TO FIND WORKING!!!!

Also NOTE if charge from solar you need a step up besides the step down. SO BOTH would be recommended!!!!

But basically I have XT connectors everywhere. on all power devices and cells.

And of course you have to make your own adapters.

Another BONUS NOTE!!!! THAT MOST PEOPLE DON'T THINK ABOUT!!!!

You can use a cigarette lighter plug or clamps for direct contact to any lead acid type battery or solar panel plug.

THEN this becomes interchangeable battery charging system!

Just be smart and check your voltages and have converters. Why I have 2 plugs on battery to charge and use at same time! ENJOY!

Step 5: Muti-Use

Can have many applications!

Cables and adapters!