Introduction: Tim's 5W Solar Charge,12VDC 4.5AH Portable Power Supply.
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About: Principal Consultant cum Trainer for Lean Management.
He graduated from a Technical College majoring in Mechanical Engineering and is also a Certified Kaizen Specialist and a hands on TPM Lean Facilitator …
This Project is primarily design for charging communication equipment & gadgets like Laptops,Hand phones, GPS, LED lights while doing mission work in remote area without Grid Electricity Supply.
The capacity of the Power Supply is sized for above personal equipment with portability,availability of material,cost effectiveness & flexibility in mind. 5 Watts Solar panel pumping out 17 Volts was targeted so as not to overcharge Internal 4.5 AH Lithium Ions batteries with only blocking diodes to maintain Simplicity.
From the desk of :
Timothy Wooi ,
20C, Taman Bahagia,
06000, Jitra, Kedah,
Malaysia.
email:timothywooi2@gmail.com
http://facebook.com/timothywooi
32 Comments
11 years ago on Introduction
Awesome idea. I am going attempt to build the project. I have some a123 batteries laying around from old VPX packs. Wonder if I could use these..here are the specs...
http://www.elektromodely.sk/A123/APR18650M1_2007-05.pdf
12 years ago on Introduction
Very cool!
Reply 12 years ago on Introduction
far play but i have made a laptop that powers and charges its self ave had it on for about 3 days and the unit you have is big once the unit i have is finished it will be smaller than a laptop charger but good jop
12 years ago on Introduction
Very nice project!!!
12 years ago on Introduction
I believe it is only a matter of time before your batteries go up in flames; yes the diode is all you need to charge but what about over charging; also i believe you wouldn't get the necessary amp out of the device to charge and discharge at the same time; if you regularly monitor the heat of the battery with your hand, that would work, but you should add a switch in for charging and discharging.
Reply 12 years ago on Introduction
Well no one can change what you beleive,but Ive been using this set up almost half a year without any problems and will stick to this set up.Engineering is such that Input & output once match with a little 10% tolerance is ok & I dont need a switch to intentionally waste Energy to discharge it.I have a 9 units LED lamp again design to discharge the fully charge batteries over a time of 8 hours usage.I normally connect the lamp up to get light at night at the same time discharge it. Lean Thinking is all about not reinventing the Wheel.
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Reply 12 years ago on Introduction
The chances of it blowing are low. But its like how you should use an ESD strap when woring on electronics. The probability are slim to none.
I would like to see your cuircit to. The charging cuircuit I use is a slew of 2 op amps and 3 transisters
Reply 12 years ago on Introduction
Since there are request for a circuit for this KISS(Keep it Stupid & Simple) project ,meeting 90% of my needs, Ive added a 15 V Regulator circuit for you all to use as a Constant 14.3V Charger.
Please bear in mind that incoperation of this Circuit will lower Charging Efficiency as for the Panels to charge, you need more than 15V to biase the Regulator. Below that threshold, it will not conduct thus Charge.
As for me ,I personally do not us it as mine charges as long as I have more than 13.5 Volts at Panels giving 12.7 V at Batteries terminals.
( as the Diode drop off another 0.7Volts)
Lean is all about using minimum resourses to add value to meet your requirement tapping on law of Nature & Equilibrium to acheive that Goal
Reply 12 years ago on Introduction
All you would have to do is use protected batteries. You can also buy the circuit for $1.25 per batt. Saves a whole lot of worry and has hi and low protection so you don't drain them too far. Drain them too far and you just made a very expensive paper weight.
12 years ago on Introduction
If you ad some kind of hand-wound dynamo for cloudy days you'd have a perfect device! Or perhaps an auxiliary power input, for a variety of sources.
Great project!
Reply 12 years ago on Introduction
Tks buddy,Yes you do that or even add a 12 V dynamo with collapsible 36" PVC blades on top of a retractable Fishing rod to tap on Wind Energy (if there is)
Reply 12 years ago on Introduction
I was thinking the aux input could let you do something like that, but still keep the handy portable charger.
12 years ago on Introduction
cant wait to see your charge circuit... probably the most important part of a build like this.
Reply 12 years ago on Introduction
Since there are request for a circuit for this KISS(Keep it Stupid & Simple) project ,meeting 90% of my needs, Ive added a 15 V Regulator circuit for you all to use as a Constant 14.3V Charger.
Please bear in mind that incoperation of this Circuit will lower Charging Efficiency as for the Panels to charge, you need more than 15V to biase the Regulator. Below that threshold, it will not conduct thus Charge.
As for me ,I personally do not us it as mine charges as long as I have more than 13.5 Volts at Panels giving 12.7 V at Batteries terminals.
( as the Diode drop off another 0.7Volts)
Lean is all about using minimum resourses to add value to meet your requirement tapping on law of Nature & Equilibrium to acheive that Goal.
Reply 12 years ago on Introduction
Theres no circuit except for 1 Blocking Diode IN 4001 in series to the positivevs
Reply 12 years ago on Introduction
That's a highly dangerous way to charge lithium-ion batteries. (e.g. no overvoltage protection at all.)
Li-Ions are supposed to be charged only with a current-limited constant voltage source - a solar panel with a blocking diode and nothing else is anything but that. Such a simple charging mechanism will result in either dangerous overvoltage/overcharging of the batteries, or if the blocking diode always keeps the battery below maximum charge voltage, significant undercharging of the batteries.
Reply 12 years ago on Introduction
'Supposed to' is a bit misleading. 'Best' is probably a better word. They will charge like this just fine. But as I said before,
All you would have to do is use protected batteries. You can also buy the circuit for $1.25 per batt. Saves a whole lot of worry and has hi and low protection so you don't drain them too far. Drain them too far and you just made a very expensive paper weight.
Reply 12 years ago on Introduction
You are right as overcharging lithium ions batteries are dangerous but te batteries ,panels, min/max charging voltages cum current for a 7 hr exposure at extremes had beed evaluatee and match to preent such,thus this simplicity.Im fine with this set up & had been usint it for months enjoying it without any fear/problems or hazard to bother me.
Reply 12 years ago on Introduction
Judging by the low output of these panels, I can't personally see overcharging to be a problem and think that the more bits and pieces that you put in between the panels and your device, the more power will be lost along the way.
I like this idea!
Windy
12 years ago on Introduction
I like this. The fact it was born out of necessity and not a whim and that it is simplistic and practical are awesome.