First off, I wouldn’t expect many people to click on this article because who the heck doesn’t know what a rechargeable battery is. So for that reason I added to the title “Where There’s Smoke…,” implying that there is fire somewhere. I am not referring to literal fire, though some rechargeables have been known to cause them. What I mean by that is where you see a name brand on a rechargeable battery, be careful to not pay too much for the name, instead of getting the most milliamps-hours for your buck.
And, besides anything you might learn from this article (which I hope is something), how many of us have enough rechargeable batteries should the collapse happen today? Hopefully we also a solar battery charger, which I’ll get to as well.
What is a milliamp-hour, usually labelled as mah, like 3000mah? A milliamp is a thousandth of an amp, and if you have followed our solar articles in this series, you’ll already know that amps can be confusing, because they are rated at a given voltage, so they can seem like a lot of power when in fact they are not. I’m not going to get into the math yet again, but apples to apples, always check what the mah rating is on whichever brand of battery you decide to buy.
If you want to know your draw rate on a given radio or appliance, check out the adapter. If the radio takes 6 AA batteries, it is most likely running at 9 volts, and the adapter will be a 9 volt adapter. If the adapter says 800mah, you know that your radio is running at this rate, so if you put 6 AA batteries in it that are are rated at 800mah (which would be a pretty butch radio), you’ll get one hour out of it. When batteries are run in series, to increase their voltage (each AA battery is 1.2-1.5 volts), the capacities average. They don’t add up.
I used the 3000mah number above because if you look around, it is tough to find an AA rechargeable higher than that. Regular Energizer AA batteries that come with a charger at Walmart are 1300mah. It isn’t that Energizer doesn’t make a more substantive battery. I found what is actually a pretty good deal on 2400mah Energizers on Amazon just now in fact. It just seems that ignorance is the order of the day with rechargeables, and you have to be careful with your numbers. Before I began this research I bought some Tenergy 9v batteries from Amazon, and it turns out that I could have gotten more than twice the mahs for the same price or less on Ebay.
So lets get into Ebay for rechargeable batteries, where, as you may already know, I have found the majority of my prepping needs (and no they don’t advertise here). When it comes to rechargeables, it seems as though there are large wholesale distributors using Ebay to sell bulk to retailers here in the US, and you can get very high mah batteries for as cheap or cheaper than store bought batteries with half the capacity. For instance, this ad for 48 3,000mah AAs for $23.99 is ridiculously cheap.
C, D, and 9v batteries seem to go for a lot more than the AA and AAA, because for C and D they are much more power, 5,800 and 10,000mah hours respectively for the , and for 9v batteries it is because they are actually made up of 6 smaller cells and they are expensive to make. Beware that with 9v batteries there are ranges from 250mah all the way up to 900mah. I found that these 600mah lots are a good buy compared to the other sizes, considering I got taken on Amazon for the 250mah. The rechargeable Energizer 9v batteries are only 175mah ouch.
A lot of these sellers will bundle a charger in with their batteries, and obviously you should make sure that you have a charger for all of your sizes. AAA, AA, C and D batteries are all the same voltage. There are large 6 volt rechargeable flashlight batteries, and obviously 9v batteries need their own charger. Chargers add only about $5 to the cost of bulk battery deals.
The question is whether or not you should invest in a separate solar charger. I vote yes, because otherwise you will be a slave to your power inverter if you plan to charge your batteries from a solar or wind system. Please see our solar articles if you don’t know what this means.
To charge AAA – D batteries 4 at a time, I found this guy who sells a 160mah solar charger for $39.99, and he also has deals on up to 20 of them. I also found a nifty charger that has a voltage switch from 3v to 12 volts, but you would have to get some battery boxes, like this one that holds 8 D batteries. You could of course also charge 8 of the 1.2 volt batteries in series from a standard solar panel voltage controller. Theoretically you could also series together to 9v batteries to an 18v panel as well, but I wouldn’t do it without a controller.
Can I recharge any Lithium battery? NiCAD?
The short answer to this is yes, you can, but you won’t get the full rated power back out of it, and it will probably only last a few times. There is a subtle difference between lithium ion batteries, which are the standard rechargeables, and regular lithium batteries, which are disposable. I include this point because I think there is a misconception out there that lithium is lithium.
All NiCAD batteries are rechargeable, but you’ll find that in the small battery sizes NiCADs hardly even exist anymore, and they have way less capacity than lithium ion.
Don’t Forget Your SureFire!
If you have flashlights or optics that take the CR123A size 3.7v battery, orA the larger 3.7v battery, you need to get some of those as well, and a separate charger. The good news is that they exist on Ebay as well. It looks like 2300mah is the larger capacity size, and the batteries are a couple bucks each.
I also found that you can get button cell 2032 batteries in lithium ion with a charger, so all of my optics will have fresh batteries.
Don’t Drain Your Batteries!
From what my research shows, it is best to not drain your rechargeables down to less than half power before recharging them. I guess that is true for all batteries, so in a survival situation it is probably a good idea to figure out the drain of all battery appliances in advance, and keep records of the battery drain. Most battery driven things are more for convenience than necessity, but it would stink if you realize that you killed your flashlight batteries after a couple uses. And for this column I try to assume that most people are on a budget, so if your only investment is 4 batteries and a solar charger for your survival radio, don’t buy the Energizers, and make sure you recharge your batteries every day during daylight hours. Rechargeable batteries are fallable like everything else, so you might want to get two sets, and two chargers.
Some of the commenters on this article have brought up an interesting point about the “self discharge rate.” This is a new marketing term in the battery industry because people have noticed that (regular alkaline) Duracells, while they don’t last as long as Energizers, tend to keep their charge longer when you leave them sit. In any battery there is a tradeoff between storeage capacity and the ability to hold a charge for a long time, so regardless of which batteries you buy, it is a good idea to set up calender reminders to top of your batteries. If you use an Android phone, Google calendar is great for that because it sends you an email and gives you a notification, and even if you aren’t on Android, it’ll still email you. I also try to put away a little more storeable food every year, just in case my storage conditions aren’t as good as I hope they are. To some degree this advice is like the talking heads on TV telling you to check your generator and buy some bottled water before a blizzard, but it doesn’t hurt to mention it.