3000 mAH AA NiMH / 56 cents each
erco
Posts: 20,259
NiMH cells ain't sexy, but they're getting dang cheap. Here's a dozen cells shipped from China for $6.77: http://cgi.ebay.com/12X-AA-2A-3000mAh-NiMH-Rechargeable-Battery-Cell-MP3-RC-/110614485787?pt=US_Batteries&hash=item19c1231b1b Even if you use them once and throw them away, they're cheaper than good quality alkalines.
I ordered 2 dozen: a full 4 Scribblers' worth. Now I have no excuse for not having at least 2 Scribs doing my evil bidding at all times.
I have also been buying some Lithium Ion 18650s (3.7V, also 3000mAH) and chargers to try. But these NiMH cells are cheaper (and slightly heavier) overall, and AFAIK, safer to leave on long-term trickle charge. Quite frankly, I doubt if these are really 3000 mAH, but even if they are around 2000 I'll be quite happy. Will report back after they arrive. Unless they burn the house down. Cheers!
I ordered 2 dozen: a full 4 Scribblers' worth. Now I have no excuse for not having at least 2 Scribs doing my evil bidding at all times.
I have also been buying some Lithium Ion 18650s (3.7V, also 3000mAH) and chargers to try. But these NiMH cells are cheaper (and slightly heavier) overall, and AFAIK, safer to leave on long-term trickle charge. Quite frankly, I doubt if these are really 3000 mAH, but even if they are around 2000 I'll be quite happy. Will report back after they arrive. Unless they burn the house down. Cheers!
Comments
buyer beware
Now if you use a slow battery charger that voltage is NOT being detection then you will be alright
and the price is right
1) the charge rate is quite low and safe (~60 mA from the small cells I have), and
2) it's easy to put (N) 1.2 V NiMH cells in series directly with one or two 5.5V solar cells in series to match the voltages for peak power transfer without a fancy charge regulator.
What a great buy.... just in time too. I need some
new cells.
Hey, I just got some of those solar flashlights you turned
up on ebay.
They are really nice and pretty bright.
They sent black ones and I wanted green ones is
my only gripe. How did you manage to open them up
without messing up the case? These seem pretty
well sealed tight. I want to see how much room is in there
and hook up a meter to see what the charge rate is in
sunlight.
@Holly, have you been selling refirigerators to Eskimos?
@Holly: the ones I got were barely sealed. Can't remember if there were even any screws. I took off the keychain and easily popped the case open with a screwdriver.
I've become addicted to Sanyo Eneloops. The new ones are only about 2000mAh, but the long shelf life more than makes up for it. No dead robots after a week of sitting on the shelf.
By the way, MAHA POWEREX 2700mAh are around $3 each from www.thomasdistributing.com which isn't too bad a price. I used to use MAHA almost exclusively before switching to Eneloops. MAHA has since come out with their own low discharge batteries (Imedion) but I've never used them.
That assumes I get the cool plan working of course; if I don't, it won't matter and the key will be saving the money in the first place.
The AAA's come out at about 300mAH.
I'm curious what you think about them and what type of applications they are good for. I just purchased two dozen myself.
I've read that Duracell NiMH are better than Energizer's NiMH batteries. I have a bunch of Energizer NiMH and they do not hold there charge long.
I recently purchased some Eneloops at CostCo. I haven't opened the package yet but I've read they're good (and not just from schill).
I'm also tired of having to plan ahead and charge batteries in order to use my robots. I'd rather have them ready to go all the time.
Duane
This goes back a few years, but I heard that there was a big difference between Energizers made in Japan and Energizers made in China. At the time, it looked like they had stopped making them in Japan. I managed to find some of the Japanese ones and they seemed pretty good. I didn't compare with the Chinese ones.
We have now got almost all the batteries in the house as rechargeables - even wall clocks and TV remotes. As various batteries lose their capacity (as measured by the charger) they end up in the bin, and interestingly, my collection of rechargeables is now almost 100% duracell.
Good info, I'll test them. Even if you're right though I'm way ahead because even domestic NiCD's of about that capacity are way more expensive. If my robot works I can always upgrade. I'm trying to get a cheap project off the ground though and "working at all" is fine.
With energizer batteries and energizer chargers, my PP3's used to do ~200 cycles. With the MAHA charger I just threw out my first one at over 900 cycles.
E-bay NIMH are garbage. Cheap garbage, but I use them in my RC cars, all my remotes and even my noise cancelling headphones when I fly. They end up costing me less than .85c each, but when teamed with a real charger that treats them nicely I've not lost any yet to cycles... they may only hold 1/10th of their rated capacity, but they've been doing it for a couple of years, so I've more than got my moneys worth out of them.
I also have some Eneloops, and to be honest they are worth every cent, but only in stuff like keyboards and mice when you don't want to be swapping the batteries every 3 months.
Cheap Chinese are ok, but you *must* have a good charger. Can't recommend the Maha Wizard highly enough. Really.
I'm thinking about this one.
Any other suggestions?
Duane
That C9000 does a lot more stuff than the C808. I'm thinking about getting one of those also. It only does 4 cells at a time and only AA and AAA. The C808 is able to do C and D size and up to 8 at a time. The Maha chargers are all individual, I can charge any combination at the same time or different times. They work like having 4 (or 8) individual chargers. The only con is that they don't do 9-volt.
Which is why next to my MH-C9000 I have an MH-C490F. Brilliant little machine
I'm sure a nice charger (or even a trickle charger) can put more power into them than the cheapie wall fast charger I used, so this is kind of a worst case scenario. Will advise initial findings.
-Phil
If that's your definition of a good day, then things are freakin' FANTASTIC here!
BTW, I'm testing the batteries at work, so worst case, if there's a fire or explosion: AFTERNOON OFF!
Life, lemons, lemonade again!
Yikes, BradC is right on the money. Even at fairly low continuous drain, my quickie test puts them only in the 500-700 mAH range. I had two cells in series hooked up to a DC motor under light load, so the current started at 500 mA and slowly dropped, as did the voltage. After one hour, we were down to 2.2 V total and 440 mA. By 1:10, 1.5V at 350 mA.
So not 3000 mAH by a long shot. No good for mission critical applications!
What do you suppose you are going to do wrt feedback on this purchase, erco?
Regarding feedback, I find that most China sellers are quite eager to please. Many of them will refund 100% of your money in exchange for good feedback. In this case, the price and risk was low. These particular batteries are low-grade, more like Ni-Cad cells, but certainly worth something. I'll find a use for them. It would be wrong to expect a full refund; the shipping costs alone from China had to be something. I'll probably ask for a partial refund, maybe half and see what they say. I will mention the lower capacity in my feedback, but give them good stars for customer service.
My cells feel pretty lightweight, that might be some indirect indicator of chemistry or capacity. Each cell weighs 18.7 g, whereas a standard Duracell alkaline AA weighs 24.6 g.
-Phil
If the capacity of the batteries aren't close to what the seller stated they should be called out for it. It's deceitful, especially if the seller knows their claims aren't true.
I ordered a couple sets of these batteries. If they're not at least 2000mAh I'm going to leave negative feedback. I will cycle the batteries a couple of times and try to get the batteries up to their maximum capacity before complaining (or blaming erco as an accomplice).
Duane