One thing to note about Solar is that it's usually less than 10% efficient, even with Fresnal lenses. You may want to look at other options as well (to combine with a solar station) such as wind or even a Peltier device.

I don't think that's an issue here. OP gets the sunlight for free. Inefficiency just means it takes longer to charge, but it's still free. The general recommendation has been to find a lot of solar cells and wire them appropriately to get current/voltage for requirements.

Don't think she'll have much luck scrounging Peltier junctions in the trash; and their efficiency is in the same ballpark as solar cells.

 

Thanks for the PDF @dl324. I want to point out that this isn't really a viable way to use batteries, as the article pointed out. Better to use recharagable batteries from the start. One thing I forgot to mention to the Thread Starter, be very careful about draining batteries too much. Some batteries can be permanently damaged if they are discharged completely. Lead Acid batteries, for example, typically cannot be discharged much more than 50% of capacity without causing permanent damage. Always follow manufacture's guidelines.

 

Thanks for the PDF @dl324.

Always glad to help...

I want to point out that this isn't really a viable way to use batteries, as the article pointed out. Better to use recharagable batteries from the start.

Agree completely, but if you're trying to extend the life of what you already have, or can acquire for free, this is a reasonable solution.

FWIW, I was a fan of rechargeable alkaline batteries. I invested a couple hundred dollars in something that was unproven and was only on the market for a short time. I imagine Ray-O-Vac was losing money. I was getting replacements until I figured there was no future in the technology.

 

I sympathize with your situation, and I'm embarrassed by the rudeness you've encountered. I think you're on the right track with solar power and rechargeable batteries, but you'll need to get past the high cost somehow. Using discarded garden lights are a good first step, and the less you have to modify them, the better ie use them directly in your garden. Now, charging batteries requires more than simply hooking up a solar panel to the battery being charged. You'll need a charge controller (called a charger) and that's an additional cost. Harbor Freight Tools sells the panel and charger together, and that will probably be the best deal if you can find a way to pay for it. I don't know how well a car alternator/bicycle would work -- some people have tired it and found it fails. However, some stationary exercise bicycles use a small DC generator and resistive load, and if you were to scrounge the right kind, you could disconnect the resistor and use the output from the generator, again however, you'll need a proper charger. Forget using capacitors, they are terrible for storing power and they can be dangerous.

I seriously can't think of a better way to get what you need. I'll try to provide assistance any way I can.

Thank you. I do not know how far back you read but I do have a bevvy of circuit boards pilfered from discarded children's toys and small electronics from which I can pull (and am in the process of doing so) electronic components like capacitors, resistors and switches. I have the know how to build circuit boards of my own I am biding my time until I can get hold of some unused boards that way I have the ability to build up some of the things mentioned here instead of having to buy them. What I don't have is the capability of building things from imagination. I am limited, at this time, to the ability to reverse engineer or copy what I see.

 

Thanks for the PDF @dl324. I want to point out that this isn't really a viable way to use batteries, as the article pointed out. Better to use recharagable batteries from the start. One thing I forgot to mention to the Thread Starter, be very careful about draining batteries too much. Some batteries can be permanently damaged if they are discharged completely. Lead Acid batteries, for example, typically cannot be discharged much more than 50% of capacity without causing permanent damage. Always follow manufacture's guidelines.

Thank you! I do not have a huge amount of experience with lead acid batteries so I did not know that! No wonder why I have such a problem with car batteries! I cannot begin to count the number of times I have had to call my dad to bail me out of a dead battery on the side of the road...daddy did, however, teach me to follow the manufacturer's guidelines on [everyday] batteries.

 

Thank you. I do not know how far back you read but I do have a bevvy of circuit boards pilfered from discarded children's toys and small electronics from which I can pull (and am in the process of doing so) electronic components like capacitors, resistors and switches. I have the know how to build circuit boards of my own I am biding my time until I can get hold of some unused boards that way I have the ability to build up some of the things mentioned here instead of having to buy them. What I don't have is the capability of building things from imagination. I am limited, at this time, to the ability to reverse engineer or copy what I see.

Just checking, do you have a soldering and desoldering tool handy? Those will help significantly.

Don't think she'll have much luck scrounging Peltier junctions in the trash; and their efficiency is in the same ballpark as solar cells.

That's why I was suggesting using them in conjunction with the solar panels. Some cooling devices have Peltier devices built into them, and you'd be amazed how many people throw away such coolers.

Can you cite some sources for this information? When I was a child, they used to sell chargers for recharging primary batteries. And I remember seeing Dick Clark advertising something on TV within the past 20 years.

To that end, here is a reference from 1998 that says it is possible.
http://techdoc.kvindesland.no/radio/psu/20061103160627551.pdf
I assume these articles receive some sort of Peer review before being published...

Certainly primary batteries will leak or explode if stressed when recharging, but so will rechargeables. I just had a NiMH AA battery leak in my charger and the fluid was a very effective paint remover.

I have some hand crank LED flashlights that charge a CR2032 battery. This clearly goes against what's in the datasheet, but they do it anyway (and don't have a problem with exploding batteries).

I'm not saying it can't be done, but due to the chemicals used in alkaline batteries, they are much more dangerous if they fail. And trying to recharge them does increase the chance of failure. It's generally better to avoid trying to recharge them altogether.

 

Hi UnityInDiversity,

Many of us would choose to pursue an elegant solution for a seemingly simple problem.

In your case, you need not worry about charging batteries the "right" way. It will just require more ingenuity and labor on your part. Charging a 12V lead acid battery can be as simple as connecting a solar array that produces more than 14V or so and adding a diode in series to prevent your battery from discharging through the solar cells when they aren't producing enough voltage. If you can build a regulator circuit, you can extend the life of the batteries; but the reality of the situation is that you won't likely be generating enough current to charge lead acid batteries "correctly".

If your objective is to store energy from sunlight using what you have available or can obtain free, or at low cost, something is clearly better than nothing. You can address changing requirements as you go.

 

do you have a soldering and desoldering tool...

There are battery operated soldering irons, but you can go old school and use a fire to heat the tip. To remove solder, there are spring operated solder suckers or you can use the braid from coax cable (works best if you apply rosin/flux).

 

Always glad to help...
Agree completely, but if you're trying to extend the life of what you already have, or can acquire for free, this is a reasonable solution.

FWIW, I was a fan of rechargeable alkaline batteries. I invested a couple hundred dollars in something that was unproven and was only on the market for a short time. I imagine Ray-O-Vac was losing money. I was getting replacements until I figured there was no future in the technology.

Nice that you should mention unproven as part of the reason I am looking to charge batteries first instead of directly charging my devices is that my skill at this is quite unproven and I would hate to ruin one of my devices attempting something that I do not understand fully since knowing the basics of how to and actually doing are two very different things. I have my eye on great things and the understanding to know that some of these will take much time, trial and error before something working prevails.

I did download the PDF of the first text to my [phone] SD card and have been reading through that to build back my knowledge of the basics. Education is a part of everyday life and I embrace it daily!

 

I find it hard to believe that you cannot charge your cell phone or flashlight batteries but you can remove components from circuit boards and make your own PCBs. Are you using the Fresnel lens for soldering and desoldering?

Bob

 

There are battery operated soldering irons, but you can go old school and use a fire to heat the tip. To remove solder, there are spring operated solder suckers or you can use the braid from coax cable (works best if you apply rosin/flux).

I got a soldering iron out of a dumpster. A clipped power cord is not likely to discourage the likes of me!

 

I find it hard to believe that you cannot charge your cell phone or flashlight batteries but you can remove components from circuit boards and make your own PCBs. Are you using the Fresnel lens for soldering and desoldering?

Bob

I use coals from my charcoal grill turned campfire pit to heat the tip of my soldering iron.

 

To remove solder, there are spring operated solder suckers or you can use the braid from coax cable (works best if you apply rosin/flux).

Sometimes, removing solder without rosin is impossible. Rosin costs (though not much) but since it's little more than Pine sap, you might find some free rosin in the Pine trees in your area. Mind you, I've never tried this before, but it might just work. See if the solder flows better when applying it.

 

Hi UnityInDiversity,

Many of us would choose to pursue an elegant solution for a seemingly simple problem.

In your case, you need not worry about charging batteries the "right" way. It will just require more ingenuity and labor on your part. Charging a 12V lead acid battery can be as simple as connecting a solar array that produces more than 14V or so and adding a diode in series to prevent your battery from discharging through the solar cells when they aren't producing enough voltage. If you can build a regulator circuit, you can extend the life of the batteries; but the reality of the situation is that you won't likely be generating enough current to charge lead acid batteries "correctly".

If your objective is to store energy from sunlight using what you have available or can obtain free, or at low cost, something is clearly better than nothing. You can address changing requirements as you go.

Necessity is the mother of invention and for me, it does not have to look pretty, it just has to do its job...so off to build Frankenstein's solar array I go...

 

[snip] I would hate to ruin one of my devices attempting something that I do not understand fully since knowing the basics of how to and actually doing are two very different things.

Many handheld devices have now standardized on charging from a USB port. If you build a 5V power supply (powered from your 12V battery) using a readily available (from scrapped electronics) 7805 voltage regulator, you can attach a USB cable and use it's mini/micro USB connector to charge your device batteries in place.

A 5V power supply powered from your battery will waste power. If that becomes a future issue, you can build a switching regulator (also from salvaged parts). The MC34063A is widely used and adjusting the output voltage, if necessary, is just a matter of changing a resistor or two.

 

I use coals from my charcoal grill turned campfire pit to heat the tip of my soldering iron.

I think that officially makes you a blacksmith!

Bob

 

I think that officially makes you a blacksmith!

Bob

I am what I need to be in order to survive.

 

[snip]Rosin costs (though not much) but since it's little more than Pine sap, you might find some free rosin in the Pine trees in your area.

I should have mentioned that... You'll want to mix the pine sap with isopropyl alcohol. Make it thick or thin, concentration isn't that critical. You can probably use other solvents.

 

I use coals from my charcoal grill turned campfire pit to heat the tip of my soldering iron.

This is off topic, but do you make your own charcoal? I plan to do it when I start melting down aluminum cans (I got tired of getting cuts while cleaning to recycle).

It would be easier to buy charcoal (or propane), but I'm retired and have a lot of time and a lot of trees.

 

Check out hand cranked battery back up for charging Cells phones.. what about using a lawn motor connected to alt to charge car batteries ?? Or connecting a small genator to a wind mill blade.. Also if you have a local advance or auto zone close to you then they will charge you batties for free .. But you just have to wait..Also how you eating ??