Step 9: I want more current!

More current would allow you to charge your batteries faster. To double the current output you need to connect the solar panels in parallel. Connect the positive terminal of one panel to the positive terminal of the other panel and also connect the negative of one to the negative of the other. This will give you a max rating of 3V at 300ma. The circuit diagram below shows the solar cells connected in parallel. You can see that the voltage is the same at 3V but now the current will be doubled.
<p>Hi, I have a system producing continuous direct current voltage at 0.5 V. Can I charge a battery using your system setup? </p>
<p>i charged a li-ion battery but the problem is that it is charging for a while and then stop charging..then again starts charging...this happened all over the time and my battery discharged.</p>
awsome thanks<br>
The moment I read that you wrote that modern LEDs don't need a series resistor... That's a preposterous thing to say and it's blatantly wrong.
<p>Why is the positive lead of the solar panel connected through the diode to the positive lead of the battery? This type of design will lower the potential energy rather than increase. </p>
<p>I actually read about it on http://inplix.com</p>
<p>I actually read about it on http://inplix.com</p>
Hi there. great instuctable I already learned alot! now Im a girl haha but love to mess with junk. i set up the i sides of an old car charger input(12/24v) output 5v. I soldered a usb female to use for cellphone charge. I then put 10x1.2vAA in series to get the charger alive (10&times;1.2=12v) and It works! now my question is...i want to use it with solar for long bikerides. that is connect solarpanel to get juice for gps, phone, music ALL DAY riding. So can I charge ALL 10 in one go? they are now soldered in series. I get that the VOLTAGE should be around the packs size (12v) BUT WHAT ABOUT THE AMP?? My batteries are 380mah/a piece so in total (in series) 3800 what should i do? a 10th of 380mah not to overcharge or 1/10th of 3800mah?! or should i put individual wires from each battery to the panel (like a funnel) to make power go directely to each battery. sorry if i sound stupid but i cant work out HOW to do it-or if it is even possible to charge 10 AA's in series. thanks ANY HELP IS APPRECIATED!! Regards Lisbeth
<p>what will be total cost...can anyone tel me?</p>
<p>sir i have 3 watt ,12 v solar panel , i want to make recharble light through this panel, please help me to decide the value of light and battery</p>
<p>sir i have 3 watt ,12 v solar panel , i want to make recharble light through this panel, please help me to decide the value of light and battery</p>
can you do or share a link to one with a battery charger indicator and two USB ports as well
<p>I have been using Solar panel 3.5 volt 400mA to recharge 2 ,1.5volt batteries and run up to 3 leds in my instuctable (Bronze steampunk solar light) I used an old solar garden light (broken) and used the circuit inside instead of a diode.Now I bought 5 new diodes and didn't know where to put it .today I found your (instuct&quot;</p><p>and was very impressed with your explaining and now understand much more.</p><p>(SEE even at the age of 70+one can learn more .thanks Zvi..(JIMMY)</p>
Thanks this has really helped, Im trying tho get a pair of solar panels which are the same size as yours to power a water pump and charge a battery at the same time. Any suggestions
<p>Hi </p><p><em><a href="http://www.instructables.com/member/Keohohina/" rel="nofollow">Keohohina</a>, </em>did you ever get a answer to your post? </p><p>I'm trying to build one <br>that powers a fan for a dehydrator and also charges the Ni-cad batteries <br> for it and I'm running into snags. I'd like it all to be real simple, something I can build cheap, maybe with the stuff in my junk pile, but also have overcharge protection and an indecator that its charged. Looked all over the internet, cant seem to find what I want. How did you fare?</p>
<p>Hai </p><p> i want to make solar charger to charge two batteries simultaneously of the spec</p><p><strong>Voltage <br>: 14.8V </strong></p><p><strong>Capacity : 5400 <br>mAh </strong></p><p>how many solar cells would be required , the circuitry and the weight of the total set including the solar pannels</p><p> thanks</p><p><br></p>
<p>Hi,</p><p>some basic questions :</p><p>1) how to calculate the resister and diode value in regard of the Watts (solar panel). It means when we buy a 10W or a 30W or 60W how could we know (calculate) the best resister and diode to also buy ?</p><p>2) how to calculate the good battery to buy following the panel we choosed ? By example if we buy 4 panels of 3 watts that we will put in serie (or in parallel) how could we be sure to buy the best battery ?</p><p>Sincerely thanks ;-)</p>
<p>Could I have another link to buy a little kit as shown? Or better that's not too expensive? The shop linked up is deleted :/</p>
I'm using three dollar store yard light panels and I was wondering if a Zener diode would work. I have one in my junk box. 20V, Pd 1W. Will this fly? <br> <br>I'm building an AA and AAA battery charger. <br> <br>
If you want to use a 3 V solar panel, then you have to buy it<br> But Commercial Solar Panels are Expensive!<br> Fact: It will take you more than 10 years to pay back<br> Solution: Using Surplus Solar Cells You can get pay back in 1-2 years<br> There is an Engineer from Chicago his name is John Sommer<br> He explain it All in his Blog&nbsp;<a href="http://topdiysolarpanels.com/" rel="nofollow">http://topdiysolarpanels.com/</a>&nbsp;
How can i use 4V 100ma Solar panel in the above manner?
Commercial Solar Panels are too much Expensive!<br>Fact: It will take you more than 10 years to pay back<br>Solution: Using Surplus Solar Cells You can get pay back in 1-2 years<br>There is an Engineer from Chicago his name is John Sommer<br>He explain it All in his <br><a href="http://topdiysolarpanels.com/" rel="nofollow">DIY Solar Panels</a> Blog<br>Search for him using Google - look for &quot;Top DIY Solar Panels Review&quot;<br>or just use this link <br><a href="http://topdiysolarpanels.com/" rel="nofollow">http://topdiysolarpanels.com</a>
Can the 1N5817 diode be use with a 6v solar panel (130mah) to charge 4 AA?
According to <a href="http://www.fairchildsemi.com/ds/1N/1N5817.pdf" rel="nofollow">this Data Sheet</a>, it appears to be a viable, if not over-kill type use. Is there any specific reason for using a Schottky Barrier Rectifier diode?
we can charge all types of battery?? ni-cd ,ni-pb or li-on batterirs??
No, if the battery doesn't have &quot;rechargeable&quot; on the outside (excluding the OLD style carbon rod batteries), then they are not rechargeable and will leak or explode of put in a charger for any length of time.
An improvement: add a LED with no resistor in series with the positive line on the solar panel to the battery holder. It will serve as a current limiter and a basic display as to how the battery is charging <br>eg. Brightly lit = charging battery a lot<br>Not so bright = charging more gently<br>dim = trickle charge<br><br>Also *USE A RED OR YELLOW LED FOR CHARGING SMALL BATTERIES OFF A SMALL PANEL*<br>Just my ten cents :)<br>Uber
Hi, I am new to solar energy and am trying to create an emergency power light kit. In my prototype I want a solar panel to charge somewhere around 10 LEDs. First off: Is this possible if they are aligned in parallel? Second: Is it possible to over charge the batteries and if so (which would probably have a horrific outcome) how can I prevent that? Third: How might I go about getting the solar panel to charge a large re-chargeable battery which then charges the smaller batteries. I want to do this so the suitcase doesn't need to be left in the sun in order to charge the batteries. If you can't help me with any of this its alright but thank you for any information you can provide. If some of this didn't make sense please send me an e-mail and I'll try and make it more understandable<br>Ryanclark@verizon.net
I choose the gifts from myloveedhardy.com. It&rsquo;s really a good choice.
i found this very helpful.thanks but i ddnt gt to see the complete circuit with all the components listed from the start,i only saw piece by piece.i would like to see the whole complete circuit.
Hi <br> I am making solar panel jacket. In order to charge phones and i-phones etc <br>I need some help with circuit. do not know what cicuit to use. <br> <br>Please help
Question. What happens if the solar cells aren't the same? Or one solar cell goes into shade before the other? So you could end up with a cell pumping out let's say 2v @ 20mA and the other 5v @ 100mA. Would they just add up to a 120mA output ? Wouldn't the flow change direction and head into the 2v 20mA cell?
Question. What happens if the solar cells aren't the same? Or one solar cell goes into shade before the other? So you could end up with a cell pumping out let's say 1v @ 20mA and the other 3v @ 100mA. Would they still just add up to a 4v output ? or You could have a cell pumping out let's say 1v @ 100mA and the other 3v @ 20mA. Would they still just add up to a 4v output?
what happens if i get a solar panel of 4V and I have 4 AA batteries in series. would it charge?or go the opposite way? tks :)
No, you need a higher voltage panel to charge 4 AA's in series. Here at Sundancesolar.com we recommend at least 6V to charge 4 batteries.
thank you <br /> pure energy
i was playing around with my solar powered radio once and noticed that i got less static&nbsp;and the battery charged better&nbsp;when i focused a&nbsp;magnifying lens over it to the point where the solar panel appears at its largest, <br /> <br /> just a simple way to increase efficiency of the panel
what is the voltage &amp; current required for the solar cell?<br />
Does any one know how many battries i could charge with a solar panel 1.5V at 500mA
If you are trying to charge a 1.25 volt battery (which is the typical voltage of a rechargeable battery in size AAA, AA, C, or D), then you can charge ONE battery with a solar panel that has 1.5V at 500mA. Be very careful when you charge your battery because 500mA is 5 amps, and that is a lot of amperage for a 1.25 volt battery. You are in serious danger of overcharging and making your battery leak or explode. Some of the fast chargers in the stores charge at a very fast rate (800mA), but if you decide to charge your battery using the 500mA straight from your solar panel you will have to monitor your battery very carefully and check it at least each hour to make sure it isn't over charging.If you want to make it slower and easier, you will need to add a resistor to take the amperage down to a decent level of about 100-200mA. There are websites you can use to calculate what resistor you need. Try googling "ohms law calculator" or "resistance calculator." Good luck!
500 milliamps is point 5 (.5) amps. one amp is 1000 milliamps. just like 1000 mililiters is one liter. 500 mA is still a lot, and may overheat the battery, but it is not as dangerous as you put in your comment. just dont stick it to your tounge, 60 miliamps is enough to kill you (stop your heart) but i have been electricuted with 15 amp ac line like 3 times, and i cant even count how many more than 60 miliamp dc lines! and obvously im alive, so i think the point of death is more like 20 amps.
<p>Can you reconcile &quot;60 miliamps is enough to kill you&quot; with &quot;i think the point of death is more like 20 amps&quot;?</p>
Your statement is partially incorrect. 500mA is not 5 amps, it is 1/2 amp. mA stands for milliamps. Milli stands for thousand (even though you would expect it to stand for million). 5,000mA is 5 amps. I know nothing else about charging batteries, but I hope this helps! :) I need to find a way to reliably and safely charge a 7.2volt 40mAh (yes, forty, not four hundred, it's a small pack) Ni-MH battery pack without supervision. Any suggestions? DC
Oh. and BTW....<br/><br/>If you charge your battery at a higher amperage, you won't be in danger of making the battery explode unless you overcharge it. You will get a good solid charge no matter how many amps you put into it. The disadvantage to using higher Amps is that you won't get the &quot;trickle charge&quot; effect that makes the battery very full to the brim. So, if you go above the 40mA, it won't hurt your battery. I purchased some solar panels at www.sundancesolar.com that charge at a rate of 50mA. You can see my tutorial with all of the links you need to buy the stuff <a rel="nofollow" href="http://thegeekmom.blogspot.com/2008/07/how-to-build-solar-powered-battery.html">here.</a>here. I haven't posted it on instructables yet....I just wired 3 panels in series so I have a total voltage higher than the combined voltage of the battery packs. Sadly, I don't think there is a way to charge any Ni-Mh battery pack without some supervision. The slower you go the less likely you are to overcharge because you can check it more often. Good luck!<br/>
Oh yah...and thanks for correcting my math...i always forget to add or subtract the zeros....and when I say it won't hurt your battery to go over its rated 40mA, I don't mean flood it with over 4000mA all at once. :) You should safely be able to charge it with 100-200mA, or more...depending on how thorough and deep you want the charge to absorb into your battery. Recharging with higher mA will result in a more shallow charge (that is if N-Mh batteries respond like lead acid batteries to recharging). I hope this is making sense. Let me put it this way. Lower charge rates result in fuller batteries with a strong charge. High charge rates give your battery a burst of energy that will charge the battery but not to its full capacity. Thats why charge controllers are needed when trying to charge a lead acid battery to its peak efficiency. It varies the rate of current to compensate for the charge rates needed to completely fill the battery to full. Again, this is all based on the assumption that Ni-Mh batteries behave like lead acid batteries when recharging.
So I could safely connect a 12v7aH battery to a 10 amp "automatic" car battery charger and leave it overnight? How about the same 12v 10a charge on a 12v38aH battery? And what the heck does it mean if a battery says something like 7aH/20Hrs??
NO! You will damage it! Charge it with about 1 amp so it gets a nice trickle charge.
As far as I can tell you are asking if its okay to connect a 12volt battery to an automatic car battery charger? I think it will be fine because as far as i know the &quot;automatic&quot; car battery chargers will do an auto shut down when the battery is full. I haven't used one, so you better make sure that it has the auto shut down mode before you leave it overnight. I think a 12V battery is fully charged when its voltage is at 13.2 volts, so in theory your automatic battery charger should be able to detect when that voltage has been reached and then stop charging the battery.<br/><br/>7aH means that you can use the 12 V battery for 7 hours at 1 amp current rate <strong>or</strong> at 7amps for 1 hour. A 38aH battery means you can use the battery at 1 amp current rate for 38 hours <strong>or </strong>38 amps for one hour. <br/><br/>If you increase or decrease the current to more or less than one amp, then the battery life will change accordingly. Pulling less current than 1amp per hour will make your battery power last longer so it will get more than the rated 7 hours or 38 hours of life.<br/>
does that happen to be a rc(helicopter/plane?) battery?
No, it's actually a laptop Cmos battery pack.

About This Instructable


706 favorites


More by DoveP: DIY Lead Acid Battery Charger How to cut square/triangle holes in ABS project boxes Solar Battery Charging
Add instructable to: