Solar battery chargers and rechargeable batteries

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Another question:

I've got a smallish box of Duracell alkaline batteries (AA, C, D, 9V) but am considering whether we should be getting rechargeable batteries. A friend suggested NiMH batteries, but my reading suggests that the only SOLAR charger out there for NiMH is for AA batteries. Is this correct? We have too many uses for C and D batteries to leave those sizes out.

What about NiCad batteries? They seem to be more expensive than NiMH, but I've run into a couple of different kinds of solar rechargers, some of which take AA, C and D. But I don't know what kind is the "right" kind. Some have meters, some don't. Does it matter?

And am I correct that there is no such thing as a solar recharger for 9V batteries? I've never seen one.

Should we have more than one charger in order to keep more batteries charged? How long do these solar chargers last?

How long does it take to recharge batteries?

And is there a solar panel/charger that will run a radio/tape deck/CD player, or whatever while said gizmo is plugged into the charger while the charger is sitting in the sun? Or would the charger have to be charged up and then plugged into the gizmo or appliance?

You can see I don't know a whole lot about this. (That's why I'm asking!)

If you recommend rechargeable batteries and a solar recharger, can you direct me to the best buys?

Thanks in advance!

-- peg (peg@futureandahope.com), November 09, 1999

Answers

Hi, Peg, I think I can help.

Q. I've got a smallish box of Duracell alkaline batteries (AA, C, D, 9V) but am considering whether we should be getting rechargeable batteries. A friend suggested NiMH batteries, but my reading suggests that the only SOLAR charger out there for NiMH is for AA batteries. Is this correct?

A. From what I understand, NiCads are longer-lasting than NiMHs, so I've chosen to go with NiCads.

Q. What about NiCad batteries? They seem to be more expensive than NiMH, but I've run into a couple of different kinds of solar rechargers, some of which take AA, C and D. But I don't know what kind is the "right" kind. Some have meters, some don't. Does it matter?

A. I bought a couple of solar chargers from ccrane.com. They take all sizes except 9v.

Q. And am I correct that there is no such thing as a solar recharger for 9V batteries? I've never seen one.

A. I think you're right. But you can buy a regular charger for 9v and run it via a gizmo like the one I bought from realgoods.com--it can be solar charged or run off a car cig lighter and has a universal jack thingie, will run anything up to 12v.

Q. Should we have more than one charger in order to keep more batteries charged?

A. It depends on your usage. Do you know how long a certain battery-run appliance will go on fully-charged batteries? For instance, my police scanners go about 9 hours on a 4-pack of AAs. If I know how long it takes to recharge those batteries, then I know how many batteries and chargers to get. Then I add in the other battery-operated things we've got. . .

Q. How long do these solar chargers last?

A. No idea.

Q. How long does it take to recharge batteries?

A. I believe it's 7 hours.

Q. And is there a solar panel/charger that will run a radio/tape deck/CD player, or whatever while said gizmo is plugged into the charger while the charger is sitting in the sun? Or would the charger have to be charged up and then plugged into the gizmo or appliance?

A. See re gizmo described above, which can also be run through cigarette lighter. Go to realgoods.com, search on solar charger for more details. This thing will allegedly run a notebook computer. I havedn't tried it yet.

Q. If you recommend rechargeable batteries and a solar recharger, can you direct me to the best buys?

A. Ccrane.com definitely good for their own brand of rechargeables. Like their solar chargers too. But for the 12v thingie, realgoods.com is all I know. Also, Real Goods has some bigger solar panels for running things--watts in a box, I think they call them--search in their on-line catalogue for more. They have some neat stuff.

-- Old Git (anon@spamproblems.com), November 09, 1999.


Hi Pam,

Try http://www.stpaulmercantile.com/solar.htm

They have several solar rechargers.

BTW, use NiMH instead of NiCd. NiMH have higher capacity, don't have the 'memory' problem, recharge faster -- but are more expensive than NiCd.

You could also get (as I have) the Ray-O-Vac Renewal batteries. They are alkalines that are designed to be recharged (instead of blowing up or leaking as normal alkalines do when recharged). But they need a special Renewal charger (there's a tiny computer for each battery that's being charged that's designed for the 1.5 volts of alkalines (NiCd and NiMH are only 1.2 volts per cell, and these chargers could discharge the higher voltage alkalines).

-- Dean -- from (almost) Duh Moines (dtmiller@midiowa.net), November 10, 1999.


9 volt rechargables: "9 volt Nicads" are really 7.2 volt, and aren't a good substitute for real 9 batteries.

Length of time to recharge: depends on the current output of the charger, etc. A small solar charger that holds 4 AA batteries and sits in the window sill will probably take a couple of days to fully recharge the batteries. Depends on how dead the batteries are, how sunny, etc. The good thing is that they charge slowly enough that they don't overcharge to damage the batteries very fast. Larger "plug in" chargers are often automatically controlled as far as charge rate, shut off when fully charged, etc.

Hope this helps.

-- Jim (jiminwis@yahoo.com), November 10, 1999.


I have a multitude of plans and backup plans. I use the Ray-O-Vac rechargable alkaline batteries and dedicated charger along with regular "Heavy Duty" Ray-O-Vac's that I can reliably recharge in the solar charger. I also have quite a stock of standard alkalines which don't charge well in the Ray-O-Vac charger.

For raw power (not counting a generator) I have a couple of those "square foot" 6/12vdc solar panels, a couple Marine 12v batteries, a smallish inverter (140watt), and a Coleman Power pack.

I have used the solar cells to charge one large battery, while the inverter powers the Ray-O-Vac charger, and charges my laptop ;-)

Don't forget a universal convertor, 12vdc cigarette plug to 1.5/3/4.5/6/7.5/9 volts.

-- Powder (powder@keg.com), November 10, 1999.


Hi peg,

I chose the NiMH batteries because they have higher output and much longer life (greater number of cycles) than NiCad. My charging solution is:

1. Thomas Distributing has a good charger, their MAHA MH-C210 that will charge AAA, AA, C, D, and even their 9.6 volt recharable replacement for the 9v. The only trouble, as you noted, is that the charger isn't solar. Not to worry.

2. The charger will work from 12 volt sources, and comes with a 12v cigarette lighter plug-in.

3. That means the charger will work from either a 12 volt battery source or a 12 volt solar panel, even a 3 watt panel. So, I bought a 5 watt panel. I intend to add a single deep cycle battery and I alr4eady have a small inverter.

I also have a RayOVac charger which will do both NiCads and NiMHs, and can run off the small inverter and battery.

The charger I bought advertises that it will charge the NiMH batteries in only a couple of hours.

hope this helps

-- de (delewis@XOUTinetone.net), November 10, 1999.



PEG:

I've been using nicads of all sizes (AAA to cells that weigh 50 lbs each!) since 1963. When I read the specs in NiMH I got enthused and bought a whole bunch specifically for Y2K. Then I found out the downside: they have a TERRIBLY SHORT SHELF-LIFE!!! That means in Y2K when you're trying to conserve battery usage you will leave your devices turned off as much as possible -- short bursts of usage. In between the NiMH's are 'lying on the shelf' so to speak, and self-discharging (I believe the rate is >1% per DAY!)

So I went back to buying a whole passel more of plain ole nicads -- also, they're CHEAPER, not more expensive.

Bill

-- William J. Schenker, MD (wjs@linkfast.net), November 11, 1999.


PEG:

On those "9v" nicads, Jim's right, the garden variety are only 7.2v -- bad news for your 9v devices. However, there are 'true' 9v nicads (actually only 8.4v -- but nicads are 'stiffer,' i.e., work better than alkalines at the same voltage -- so 8.4v works just fine in 9v appliances. Again, don't get the NiMH 8.4v batts, only the NiCad ones: Hosfelt Electronics, 800-524-6464, Part # 9v-8.4, $8.95.

Bill

-- William J. Schenker, MD (wjs@linkfast.net), November 11, 1999.


NiMH's discharge rate is >THREE%/day.

Bill

-- William J. Schenker, MD (wjs@linkfast.net), November 11, 1999.


Thank you all so much!

I'll have to read and re-read all this and consider everything carefully, but you've given me some good information to go on. Bad news about the NiMH shelf life!

If you want, imagine me singing "You light up my life." Than again, you might not want to . . . . (grin)

Thanks again!

-- peg (peg@futureandahope.com), November 11, 1999.


Don't rule out NiMH cells entirely. For some applications, they are indispensible.

We have a couple of Cherokee FR465 FRS radios, which use either 5 alkaline AAA cells, or a NiMH pack made of 6 AAA cells (room for one more because it doesn't use the regular battery holder, so has higher voltage). The higher MAH of the tiny AAA NiMH cells makes it practical, as AAA Nicads are *quite* puny, and wouldn't give adequate service with the high-draw transmitter.

We get as good -- or better -- life per charge than we got with alkalines. Even though the alkalines have a higher MAH rating, it's based on a much lower rate of discharge. Because the NiMH cells handle high-discharge rates very gracefully, they end up being a much better solution than alkalines. This is true for any high-demand circuit, such as a digital camera (where the difference is even more dramatic -- we get maybe a dozen shots with AA alkalines, and probably 75 per charge with NiMH).

In short, any application that needs the highest output/size ratio, and is in regular use (hence, self-discharge not an issue) is ideal for them.

That said, I'm not averse to buying and using Nicads when I can get a good deal, such as the 1.6 AH sub-C cells I mentioned earlier.

-- Ron Schwarz (rs@clubvb.com.delete.this), November 12, 1999.



Someone on this forum mentioned that regular C cell NiCads were actually AA batteries in C clothing. I read the same in ccrane.com's catalogue. Sure enough, when I got my C. Crane house-brand NiCads, their C batteries were considerably heavier than the Eveready NiCads I had.

Also, I have some NiCads that have been in HEAVY (scanner) use since I started using NiCads 5-6 years ago.

-- Old Git (anon@spamproblems.com), November 12, 1999.


When you're evaluating Nicads (or NiMH), you want to pay attention to the MAH (or AH) rating.

An alkaline AA will put out something like 2300, presuming it's not drawn out at a very high rate (i.e., radio transmitter, digicam, etc.) An AA Nicad will do between 800 and 1100, and a NiMH will do between 1200 and 1500. (1200 MAH = 1.2 AH, you may see it expressed either way.)

FWIW, I've heard the same thing about a lot of D sized Nicads, although there are some "real" D cells with *very* high AH ratings, and although not real easy to find, there are some D NiMH cells with amazingly high ratings.

When you get a non-flashlight size, like the sub-C the guy on eBay is selling, you don't have to worry about having an AA tucked away inside.

BTW, a *lot* of appliances with sealed Nicads use the sub-C size, which is one reason I bought a passel of 'em. My cordless soldering pencil uses two, and one is shot (and the other probably not far behind). I can buy a new pack from Wahl for something like twenty bucks or so, or, I can rig in two of the sub-Cs I ordered at $1.50 each.

Same thing with cordless can openers, drills, etc. I *think* the Black and Decker battery modules (I forget the trade name, they're tubes about an inch diameter with a plastic cap on the end, maybe 5 or 6 inches long) are filled with sub-C cells too.

-- Ron Schwarz (rs@clubvb.com.delete.this), November 12, 1999.


We got a solar battery charger from Jade Mt. that will charge AA, C, D and 9 volt batteries. There is a little cap that you put on the top of the two buttons on the 9 volt battery. You can also put a converter on a wire that comes off the unit, to plug in directly any not-too-demanding unit and run it directly off solar power. Like a small tape player or radio. (You will need to solder your converter to the wire, though. It just comes with bare ends.) The wiring on the back of the unit was really fragile, but can be protected by globbing some silicone over the wiring. I got this unit so I would have a way to charge my Rotadent electric toothbrush, which I really need for my gum condition. Went to Radio Shack and got the right converter piece so I can plug the Rotadent right into it.

-- Shivani Arjuna (SArjuna@aol.com), November 15, 1999.

I sell a 9-volt and a 12-volt solar battery charger. The 9-volt will charge AA's, C's, D's at the same time, or it will charge 3 9-volt at the same time. The 12-volt will do 4 sets of batteries at the same time or 2 9-volt batteries. Here's more info:

. . . .

Triple-Array 9-volt Solar Battery Charger - Made in the US - Only $35 ($4 shipping) Four-Array 12-volt Solar Battery Charger - Trickle Charges an Auto battery - Only $45 ($4 shipping) Click Here for Solar Battery Charger Page
Don't confuse these chargers with the more common chargers you see advertised for $25. Those are made in China and only have one solar array, so you can only charge 2 batteries at a time. These chargers can charge your 2 AA's, 2 AAA's, 2 C's and 2 D's at the SAME TIME! Or, they can charge multiple 9-volt batteries at the same time. These chargers are hand made in the U.S.A. Need rechargeable batteries? We sell only the best - Nickel Metal Hydride (NiMH). NiMH AA cells cost about $3 a piece, compared to about $2 a piece for Nickel Cadmium (Ni-Cad). www.stpaulmercantile.com/solar.htm Call John tollfree at 1-888-395-1164 or at 651-452-8572 or 651-452- 9242. Best time to call is weekends until 10:30 pm central time, or weeknights 6:30pm to 10:30pm central time.

-- john (john@stpaulmercantile.com), November 16, 1999.


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