If you’ve got a solar charger packed away in an EMP-proof container (I don’t)IMHO it’s not really a big deal to put off recharging a battery. But more on that later. I also want to mention the following all-in-one solar battery charger for AA – AAA – C – D batteries. You can lacquer seal them to prevent the worst of this. This is a reasonable load, and gives a good indication of the cells true state. EBL Quick Charger with USB input(view on amzn). This leads me to believe that the detector is bad and not the batteries. The same thing goes for mice and TV type remote controls. The other thing is that one of my chargers​ plugs into the wall, the other into the solar panel. Now here is the thing. BTW, in my more expensive devices I still use the Sanyo Eneloop rechargables – those are the best. I don’t see why it wouldn’t work, you heat the battery by charging it the normal way (With a power supply to charge it +-) which gives it a charge, heating up the chemicals that are inside the battery, storing the energy. Where can a purchase this solar charger, and can you post a diagram if how you write them up? Is this kind of what you had in mind, or just an actual voltmeter? 20% of batteries are really throw aways, 40% are at 90 – 100% power. This segment came directly from WIKI…”…As an alkaline battery is discharged, chemicals inside the battery react to create an electric current. Needless to say I will not try recharging alkaline batteries again. I can’t even put into words how excited I am that I will be able to charge 3 batteries!!! They have to be overcharged to 106%. I’ll be rehoming it as I leave this site. The other thing, and something that makes me feel careless and stupid, there were some perfectly good rechargeable batteries in the box. Charging them with a car battery is a much bigger NO NO. But knowledge? ROFL. Sigh!). Each battery slot is independently monitored and uniquely charged according to the state-of-charge of each battery. Recently we purchased a 45 watt solar system with small inverter. I purchased these inexpensive storage cases for my recharged batteries. If you want rechargeable batteries, why not just buy some good-quality Ni-Mh’s or Li-On’s? Pocket-size survival blanket could save a life - throw in your bag or car. The solar DC seems to work better IMHO. I have not had a problem with Kirkland batteries leaking. And we haven’t begun figuring the rest (an inverter, the solar panel(s) which would be necessary to sufficiently recharge, the charger, etc..). Hand cranks have been used for a long time. My 2 cents worth regarding dead batteries appearing not to be dead when checked a while later – Many years ago we were investigating why our new low power parking meter design was actually using a lot less power, but the batteries were not lasting as long as in the older higher power design. The Red Cross with replace (for free) up to 10 detectors. If you live near running water, or water that can be made to move with a small expenditure of labor you could use micro hydro. I also found when testing for others to charge there were a lot of batteries that showed good on the meter. This will accommodate a battery charger which itself includes a 12-volt car adapter. All batteries test full after charging; they are now at about 65- 70% full. So I designed a solar powered battery charger, which allows you enough power to charge a single AA battery wherever the sun may shine… Then again it’s like confirming your information. You do not even need a charger just the mini solar panel wire them up in series. It takes about 2 days to recharge 4 each AA batteries…they work like new most of them anyways…it puts out about 19 volts DC the wall outlet use to put out 6 volts AC…. Off subject but congratulations Ken. A weak battery can produce nearly the right voltage without any load, but that voltage will drop dramatically when connected to a load, due to high internal resistance. It is interesting to note that many were 9 Volt batteries that came out of one of my carbon monoxide detectors. This does not work….possible batteries may heat up and explode or leak plz do not try this thx. How To Charge AA Batteries With A Solar Panel. They have actually ruined some of my electronics. Hey, laughing is OK, I’m used to it (although generally it’s ladies, and they usually wait until after I ask them for a dance/date first. I don’t understand the connection, litteraly. I’m thinking about my large maglight…. I used a charger that’s suppose to self adjust to the type of battery. It was also almost like an instant charge. Thank you! With a bit of fiddling I could get it to do 4 AAA’s at one time. And it did. AA / AAA 4 Cell Battery Storage Case (Bundle of Six Cases):  I like these little cases. So carrying some AA’s AND some D’s, maybe that adapter is not such a bad idea considering weight? Even test internal resistance. Yes, I’ve had some leak but after a while the rechargeables leak as well. Thank you for not only useful information but $$$ savings too. You can find the same or similar elsewhere, just do a search for “alkaline battery charger”. Made me laugh a couple of times, too. Have had ZERO issues with exploding batteries. You will need a “smart” charger and a solar panel. When I turn the switch to 2 LED mod, it is as bright as ever. It was something that I’ve tried to find a reliable reference for – which item performs best based on someone I trust – and you provided that. Now I know what I have and what I need to replace or add more of. While on the go, out in the field or backpacking, the following off-grid charging equipment will charge the most popular size consumer batteries (AA, AAA). I also strongly agree with you about Kirkland batteries. Currently we are living completely off the grid. The 4 in the charger have been charged 9 times. Just find the right size innertube and stretch over battery. I need to get some more of those little battery cases that I like so much. Reason: You are passing a very high current thru the dead AAA battery. I tried to charge a size “D” once when I was a kid – it blew up like a cherry bomb! This charger does it all with ease.NiMH/NiCd sizes: AAAA, AAA, AA, A, C and SubC. Submerge your dead AAA battery in 1 cup of lemon juice for about an hour. I have NEVER had a NiCad or Lithium-Ion battery leak and now use the Eneloop variety exclusively. ordering one now thanks for the info, Thank you ~ I’ve ordered the charger and also have a box of used to check out ~ Much obliged. Turn on the battery charger and begin the charge. Steve, I just loaded up the charger with eight AA eneloop batteries (partially drained) and am using the fast-charge mode (draws a bit more power than ‘slow charge’). Load the charger, set the timer for an hour, plug in the charger, the timer rings, unplug the charger. When you recharge batteries from your house electric, what is that cost? There have been times when I open up my flashlight to change batteries and find that they have leaked inside making a big mess. They produce electrical current by a non-reversable chemical reaction. another way we hacked batteries was to connect them in series or parallel or even both at the same time to create a battery pack. I don’t know if even a good tester will do this, but I know for sure that a crappy one won’t, and will therefore give misleading or incorrect information at least some part of the time. How to charge your battery: Set your battery charger based on your needs. I got a free meter from Harbor Freight – it in in their ads regularly – actually I have one in every vehicle. Each time one is successfully recharged it will loose a bit more available power. The manufacturers used to replace a product ruined by a leaking battery. As I was pondering why a few had started to leak – I mentioned this in the article – I began to wonder if it had something to do with the way they were being stored. I ran a batch of four brand new Amazon Basics High-Capacity AAA batteries through four passes of Refresh/Analyze on a MAHA MH-C9000 charger with a 400ma charge / 200ma discharge rate. Li-ion sizes: 10440, 14500, 14650, RCR123A (17340), 17500, 17670, 18350, 18500, 18650, 19670 (protected 18650), 25500, 26500, 26650. All cells exceeded the 800 mahr rating on the cells … DO YOU KNOW OF ANY WAY TO CHARGE HEARING AID BATTERIES? For now, I will charge them once until I go through the pile and then start anew. I also have a solar battery charger. I think you read the instruction booklet incorrectly or they printed it wrong: Rechargeable batteries should be fully drained before charging, NOT ALKALINES! Between DH and myself, we have 5 headlamps​ that all require 3 AAA batteries. Heat is another way the battery leaks, leaving them in your flashlight in the car will generally leak. Anyone have titles for good, fairly simple, books on this kind of lower end solar rigging? Now, some people, realizing this, will just hook an ammeter across the battery terminals. Capable of setting the charging voltage of each bay individually 9 volt batteries are particularly dangerous as the terminals are close together. Maximal Power FC999 Universal Battery Charger: This nicely built charger will charge AA, AAA, C, D, N, 9V, Ni-MH, Ni-CD, and Alkaline batteries. Recharging it, then using it, can force current to flow through the bad cell in the wrong direction. I also buy all by batteries at Costco but I don’t get the Kirkland brand…I get the other name brand they sell…is it Energizer??? i had no idea. If they would make one of these a solar unit I would buy one. The LED panels are good for 5 years on these new units! Able to charge over twice as many types of batteries as its previous model Once the battery starts loosing charge, it will stop working… when in fact that battery will work fine in other electronics. I checked on my recharged batteries about two weeks after storing them in a box in my utility cupboard. Note: When I purchased the charger, it was on back order. The little manual that came with the charger stated that alkaline batteries can be charged to 75 – 90% of their original capacity. I have a bunch of yard lights purchased years ago. Just buy eneloops and do it right,they will safely and reliably recharge for years.They wont leak as essentially all alkalines do eventually.First time you ruin something with a leaking alkaline you will see this isnt the area you want to save pennies in. This presents a significant challenge to battery charger designers. I believe I’ve seen (online) some AA/AAA chargers which will connect via a USB connection – but am unfamiliar with their practical functionality, reliability, etc.. Under the “Bargain Bin” above she lists the Maximal Power FC999 Universal Battery Charger with a link to it on Amazon. Thinking eneloops also – I saw the 10W Instapark on Amazon for $50, would it be worth it to go for the 27W at $115? Terms Of Use The cable is fixed into the adapter which is plugged into the wall and then connected to the iPhone. I’m no electrician, but PV seems not only expensive, but only works at certain times and latitudes…. I store my batteries using slits of bycycle rubber intertubes cut into 3/8 slits ( you can get hundreds from a single innertube) to cover button type batteries. OK. This process is not some kind of magic, but you can charge your Li-ion batteries without using your charger. I didn’t even know they made a charger that recharged regular batteries. Cost/watt goes down, but would the extra watts be used? Wow – I can’t believe how much money I’m gonna be saving now, thanks to you. I don’t know exactly why… it just seems like poisonous, disgusting chemical something. If it takes two hours to get a full charge on two batteries, that would be 120 minutes. If I interpreted your power requirements correctly, your cpap draws 36 watts (120 volts AC x 0.3 amps). I wouldn’t use the Alkalines in my Maglites or radios but they would offer something if they are able to hold a charge even for a little bit. I wonder what the cost of the electricity used in charging might be. You have to gather up some items before charging up your cordless drill battery. Where I live that is easier said than done so the box was pretty darn full which was great because that meant I had a lot of raw material to work with. Digital Cameras are a prime example. No problem, I have plenty more! A. I seem to recall reading there’s a possibility they can explode if left unattended in a charger. I wont bother doing that again. Charging alkaline cells are a No No. Being a dutiful citizen of the world, when a flashlight, computer mouse or portable electronic gizmo such as a remote control stopped working, I dumped the old batteries into my recycle box and installed some new ones. And after a while the rechargeables get hot in the charger. Thanks for your insight, Bill. Not everyone follows the ‘one is none’ mantra all the time. FYI, regarding ‘home’ chargers (that plug in to ordinary 120VAC home wall outlets), the one that I’m currently using is: I haven’t done it since, because I was afraid they might catch fire from overcharging. There is a slider switch that allows you to select the type of batteries you are charging – they can not and should not be mixed and matched by type (although, as I mentioned, various sizes of the same type work just fine.). They are CR123R based system that are rechargeable by induction pad that is USB cable voltage feed. I check the voltage on the charger with my volt meter and it showed that it was only charging at about 1 volt. So far all of the 9 volt zinc-carbon batteries work fine in the smoke detectors. I have a cpap that keeps me from hunting as far into the back country as I would like. And now trying with normal Alkalines too. Peace, my friend. Cute. Can brand batteries such as Duracell/Enegizer AA AAA be used instead of AA AAA NiMH as I have a large quantity of them. This 21 watt solar panel is portable, folds up, and provides the correct output operating voltage and minimum current requirements to power the charger listed above. Solar panels come in many sizes, shapes, and various electrical specifications. Put a piece of black electric tape over the terminals. Plus, it had the ability to test 9V batteries as well as button batteries and the traditional AA, AAA, C and D sized batteries. Just replaced them today actually…Coincidence I’m reading this post now…I think not! Why would anyone remove a drained battery and not recharge-put in recharer, plug in outlet. When I have a return and there is no receipt, they look the item up in my member sales record and there is never an issue. The charger and meter won’t take long to pay for itself at this rate. For a total investment of about $34, I now have what for all intents and purposes, a lifetime of free batteries. The guide 10 plus will charge 1-4 batteries but you have to have 4 in it, dont all need to be dead though, its just how the paralell loop works, i believe they equalize and charge together. Looks like a good charger. Well, that was me. Also, high drain and high charge cause them to leak quicker. That took care of the last of my Christmas money, but what the heck…fresh salad fixings all winter long is a big morale booster, and not all disasters will involve the loss of the grid (pandemic comes to mind immediately.) Those without knowledge of the risk involved by deviating from manufacturer’s recommendations for use/handling of electronic devices should not “do this at home”. A new AA reads 1.59 volts, I get about 1.55 volts on a solar recharged battery…2 days of sunlight will charge 4 ea AA batts using my 12 volt solar panel it measures 4″ x 14″ approx. Buy cheap, buy twice comes to mind…Basically throwing money away as they don’t last long at all. Incidentally, I had several of them leak after being recharged in this particular charger. They now show high end of good on the meter. If I put them back in the charger, the green fully-charged light would come on right away but when I took them out the next morning, the tester showed them about 90% charged. You dump the batteries into the recycle box and install new ones. I also use a voltmeter to tell what the real voltage is. Additionally, this charger has a fast charge mode (the default) and a ‘soft charge’ which takes longer. I will check the power with ‘slow charge’ when these are finished charging and I load up some more…. i’ve seen news stories where people’s junk drawers spontaneously burst into flames because of spare batteries touching metal. a bunch of week batteries make 1 kinda ok battery. I’m going to try it out. The advantage of having a tester is that when a gizmo dies, you can determine whether just a single battery is discharged and not the complete set. is a little expensive but after 5 years it still works good. Eventually, the excess pressure either ruptures the insulating seals at the end of the battery, or the outer metal canister, or both. Panasonic eneloop AA New 2100 Cycle Ni-MH Rechargeable Batteries, how many watts are drawn by the maha powered when you have 8 aa eneloops in the charger. NITECORE i4 Intellicharge Universal Smart 4 slot Battery Charger, Bundle with 12V DC Cable, EdisonBright BBX3 Battery Box, 2 X EdisonBright AA to D type Battery Spacer/Converters, Features: Ya know when I was a kid 900 years ago, my Dad would charge Alkaline batteries all the time with no problems, I wonder what changed? It’s an excellent, versatile charger. And OK in the charger. I got a head lamp based and a hand held version. The main difference between the rechargeable batteries and the alkaline seems to be that the alkaline reaches their minimum faster–the point where the battery will no longer hold a significant charge and should be discarded. throwing away batteries and buying new ones is built in job security for the retailer. The cpap pulls 35 watts per hr continuous and .3 amps at max per hour. Like someone else said, exactly what I’ve been thinking about. The moon often makes for a pretty decent “flashlight”. I am so grateful that I found it and hope it can help others too. If it is grounded to the chassis, clip the positive to the positive terminal, and the negative to the chassis. @Rwt, Your problem is going to be weight. Thank you for that! I use the Maximal Power Recharger FC999 that I show in the article. I’ve been dealing with electronics and charging batteries for many years; trust me – save yourself the headaches and frustration of ruined electronics! I have ordered but yet to receive my instaspark mercury 27 solar panel. This was the first thing I thought as I saw that picture of that box of batteries. I have yet to wear the batteries out so I do not have real info on charge times. This out-gassing increases pressure in the battery. Thank you for a great article, I am on the search now for the charger and reader! What are all the options?) First, a quick note on the “tools used” for this project: SORT THROUGH THE BATTERIES AND CULL THE DUDS. To have one that can do both is brilliant! I have one on my diesel truck as well it keeps the batts full…I use boron and distiller water mix to prolong the life…3 years old now and still reading 14.6 volts. WOW. Charging such high-capacity cells could be ‘problematic’ and so there are now ‘charging bags’ available (bags that you enclose your charger in which protects against unwanted ‘side effects’ should the battery vent or explode (they’re available via Amazon of course). Nailbanger, I did that with “non-dead” batteries to complete the loop and they got really hot. You’ll need two, each with a metal cover at one end; connect the wires from the battery pack to these covers. see how silly it would be to let me rob you of hard earned money? Other than the Costco brand, I have had no additional leakers. Throw the baddies back into the recycle box. Besides now a battery cost 10 times as much. Strongly suggest anyone that even jus moderately use alkalines to seek and purchase! With a 12 volt DC battery via an inverter, the current draw will be 3 Amps (36 watts / 12 volts). You and others are simply and absolutely not “recharging” them. Checked them again with the meter. you can still keep them in cardboard boxes (no metal), i just suggest keeping them all facing the same direction and layers or rows separated by more cardboard. He left the battery in the charger until it took a full charge, good as new. Thx Nate, Let me know how it goes. (I just tested one at random with a voltmeter at 1.78 vdc.) The following off-grid charging system will charge faster and will “smart” charge today’s NiMH rechargeable batteries. FULLY CHARGED. The other two were almost charged than bam one exploded. or you can make your own holder with just some tape and wire. While off-grid, camping, hiking, a remote location, or simply for your own preparedness. I’m glad you mentioned not taking the chance if you think a battery has leaked because the chemicals in those are really dangerous. I purchased an [amazon_textlink asin=’B000RB60H4′ text=’inexpensive battery tester‘ template=’ProductLink’ store=’bds100-20′ marketplace=’US’ link_id=’424e075f-c4a4-11e7-ad5a-09a74c9dc6a6′] from Amazon. LOL All kidding aside, a good friend of mine suggested this about a month ago and I’ve been looking at some on Google and Amazon to see what’s most affordable but still reliable. You can get those at Wal-mart, Dollar General, Harbor Freight or about any place that sells tools, but these are the least expensive with a cost under $5. He said not to leave it on the other battery, just touch it quickly. I just want you to know, Gaye, that you get a ten out of ten from me. It charged it up. If anyone out there finds a less expensive portable fold-able panel (at least 10 watts or better, with a 12-volt car adapter), leave a comment and let the rest of us know…. Is that like hitting your fruit tree with a bat several times as hard as you can to “wake it up?” I know it sounds strange but we had a pear tree that wasn’t producing fruit for several years and did this. They’ll charge a lot faster; work a lot better; and you won’t be risking a fire every time you charge them! You recommend wasting money by automatically changing batteries every 6 months without even testing them. But there was no smoke and no explosion so I continued on. BUT I have had enough of them leak, of various brands, to dissuade me from ruining anymore electronics in this endeavor. I did a 9 month wilderness experiment a couple of years ago and made the mistake of not packing enough AA batteries for my radio, I had plenty of AAA batteries, but AA’s were all gone, I found that by placing an AAA battery negative post down inside a .45 Colt cartridge it makes the AAA fit perfectly inside the battery compartment of the AA powered radio. it is supposed to have reset the memory in the battery so that it will not stop working any more, as long as you keep charging it, it should work, not die, as it did before. I’ve just come back from our recycling centre with another 300 batteries ( a2, A3, C, D, 9V). I agree a THOUSAND percent (if that’s possible LOL). i found a product…called mighty Charger you can get it on amazon…it charges regular batteries and it works i have bought 3 of them and i plan to buy a couple more it allows me to use regualr batteries and regarge them…its great for the kids wii i get multiple uses from regualr batties they dont have to be recharables it does aaa aa and 9 volt the thing is great, the first one i had lasted about a year before a couple of the prongs broke, but that was more due to my under 12 children using it than the product it self. Here is the truth about the process you are promoting here. First you join the negative ends, then, if you are doing rechargeables, like he was, he set the battery in it’s charger, then he attached one end of the positive wire to the good batteries(first he joined the 2 to get 2xs the power needed), then he quickly touched the positive on the dead battery. Long story short. As far as portable panels go, I have had excellent experiences with Goal Zero. With solar panels are they in danger of being fried from EMP? I am going to play it safe and protect my devices by recharging no more than a dozen times if that. Is there a better way? My experience is that if you leave the recharged batteries in the charger overnight – or say for about 10 or 12  hours – you will get a much stronger charge. Your subscription pop-up was interesting because it accessed my browser’s SQLite database to populate an email address selection menu. Thanks for your info. It has been very cold and snowy in my neck of the woods so I’ve had extra time to hunker down and organize supplies. Suffice it to say it’s somewhere between 35 and 55 watts with a full load of 8 AA’s.