First steps in using the Sun's energy

[birrbert]

If found another interesting piece of equipment today.

I. Lithium ion 5V 2.1A USB Boost Charge Board iPhone Capacity LCD Mobile power
Link: http://www.ebay.com/itm/Lithium-ion-5V-2-1A-USB-Boost-Charge-Board-iPhone-Capacity-LCD-Mobile-power-/171319321551?pt=Battery_Chargers&hash=item27e36d63cf

I will buy one and try it out, but if anybody here thinks it's a good idea, you can test/review one too.

Other versions:

II. Lithium ion battery 5V 2A Dual USB all-in-one boost charge iPhone capacity LCD
Link: http://www.ebay.com/itm/Lithium-ion-battery-5V-2A-Dual-USB-all-in-one-boost-charge-iPhone-capacity-LCD-/111087745765?pt=Battery_Chargers&hash=item19dd587ae5

III. 1.2" LCD Dual-USB 5V 2.1A Boost Board PCB DIY Module w/ LED for Mobile Power
Link: http://www.ebay.com/itm/1-2-LCD-Dual-USB-5V-2-1A-Boost-Board-PCB-DIY-Module-w-LED-for-Mobile-Power-/321181410160?pt=UK_BOI_Industrial_Automation_Control_ET&hash=item4ac7e76370

[MJLorton]

Interesting little chargers....will be keen to hear your thoughts if you get one.

[birrbert]

Hi!

Disregarding the warning that says "this topic has not been posted in for at least 120 days."

Family is priority, so once again I've been drawn away from my hobby for several months, but I did manage to buy the first Lithium Ion charging board. I've used it for a while now and it's good, usable. My experience is subjective since I didn't take any serious measurements, but I'll hopefully manage to buy a meter with basic logging capability and check the efficiency of the board. For example THIS ONE was presented by a good ol' English man, Julian Ilett, on his YouTube channel.

The charging board physically comes in two pieces, identical in size, which connect together via some pins. Maybe this board wasn't intended for an end user, but if it was then it's a bad idea, because the two pieces wiggle and bend and twist too much, there's nothing to hold them strongly together. So, this would be a negative point. I'll point out that versions II and III have a different structure so I'll make a comparison when I have one of those in my hands.

I remain at the drawbacks and quickly mention that I found the LCD to be a very good idea, but the one they used with this charger board is not the best. It's usable, but quite hollow. The back-light has a strong blue color, but at least it helps to read the information. The display is controlled by a 12 bit analog to digital converter and shows the charge state of the battery in percentage, has a bar graph too in this regard and shows the output current.

Technically, the board does what they say: uses a 5-6 Volt input to charge a Lithium Ion battery and then boosts the electrical energy coming from the battery to deliver a stable 5 Volt output. On the input side it has a micro USB port and on the output side a regular female USB socket. It has the necessary resistors to charge iPhones or other sophisticated smartphones, tablets and gadgets. Over-voltage and under-voltage protections are a must. I believe what it doesn't have is reverse polarity protection so one must be careful when connecting the battery to the board.

I bought a Boston Power Swing 4400 battery: http://www.boston-power.com/products/swing-4400
Datasheet: http://www.tme.eu/ro/Document/a6369bd7221221e62bfbb11b3daf3733/ACCU-18650X2_BP.pdf

It seemed like a good choice for about 10 USD. What I found extremely difficult is soldering the cable to the positive terminal. The metal part there is about 4 cm x 1 cm and I was having a hard time getting the solder to stick even with my 3 mm chisel tip. First I tried with 350 degrees Celsius which is the usual temperature I utilize when soldering, but I had to go up to 450 degrees and then I managed. Although I succeeded in the end, I think I put the battery through a lot of stress. Unfortunately, the whole body of the battery got heated up several times so I'm pretty sure its life-cycle got reduced. After this procedure I did some reading and I realized that in fact I should be happy that it didn't explode in my face. So, everybody, be careful when soldering directly to battery terminals! If there's a possibility, don't do it, try other/safer methods. If you really have to do it, then do it with a very hot iron, choose a large enough tip and make very short (i.e. 2 seconds max) contact. I'll be honest and say that I don't know of other possibilities for home DIY people, so if you know of some techniques, please share.

Since I still lack a HD video camera, this would be a brief description regarding this type of Lithium Ion charging board. I connected my small solar panel to it and it charged the battery quite well. Photos below.

- Board A one side - http://i.imgur.com/6qARDKw.jpg
- Board A other side - http://i.imgur.com/NrIbdTH.jpg
- Board B one side - http://i.imgur.com/Poqc4Bz.jpg
- Board B other side - http://i.imgur.com/iI0VULA.jpg
- Assembled one side - http://i.imgur.com/asazLaK.jpg
- Assembled other side - http://i.imgur.com/VK9JMLy.jpg
- Assembled positive terminal - http://i.imgur.com/xkZSQbo.jpg
- Assembled negative terminal - http://i.imgur.com/sgfF12p.jpg

Please let me know what you think. Cheers!

[SeanB]

I think those terminals were designed for spot welding of a thin strip to, rather than for direct charging. Well done though on making it though, should be a nice charging station.

[MJLorton]

Totally respect your priorities...at the moment here it's family...and clearing the never ending piles of leaves! Fun, fun!
Good work...looking forward to seeing  / hearing how well it operates.

[birrbert]

Yes! Especially valid for me, young father, who has to acquire new time management skills now.

Sorry for my slow reaction SeanB! I read something short about spot welding, but it didn't sound to me as a home DIY thing. I would need a solution for this, because I'm planning to build a bigger capacity charging station and I have no other idea than soldering.

[SeanB]

Look for some really big high current capacity high voltage capacitors, like 4700uD 450V, and you can build one using them, or using some 1F 16V car audio capacitors ( but be aware of the fake ones out there as a lot are fake units in a big case with a rock inside to add mass) for a low voltage one, then you can build your own.

Gotta get off my ass and finish the one I was planning to build, got as far as winding the transformer for it.

[SeanB]

Totally respect your priorities...at the moment here it's family...and clearing the never ending piles of leaves! Fun, fun!
Good work...looking forward to seeing  / hearing how well it operates.

In 2 months while I am enjoying the sun you will be building snowmen.

[birrbert]

Hello!

Still on this topic, learning every time I have the chance.

I didn't like the efficiency and the build of the first all-in-one charging board so I bought the second type that I mentioned back in post number 60. This has a much better build quality, dual output and better efficiency. I also bought a a KCX-017, the USB power monitor mentioned in post number 62.

So, if it's of any value, here are some measurements:
- charging my Lithium-Ion pack needed 4526 mAh which means 16.7 W at 3.7 V nominal Voltage
- while discharging the pack provided 2960 mAh meaning 14.8 W at 5 V
- if I calculated correctly, that means an efficiency of 88.6%

Discharging was done with a small 4.8 V / 710 mA incandescent light bulb. Next I'll see if I can test this thing in a more realistic situation, i.e. charging cell phones, USB gadgets, etc. Plus I'm still planning to make use of the small solar cells and create my own custom portable small solar powered back-up. I'll get there sometimes.