D-Cell Battery Blank

[asiaeast]

I have a question along the same lines. I have a few different AA rechargers, the ones that come with a USB port, so you can charge the AA batteries, then plug in your ipod while out of the house and recharge it. Also, you can recharge anything USB, like your cell phone and digital camera. The AA batteries are obviously too small for recharging your laptop.

I basically charge the AA power packs off of a few different solar kits that I have. To sum it up, my ipod has been off the grid for 4 months now. I know, it's a little start, but I'm happy about it. Recently I upgraded my solar kit and can now recharge my cell phone directly off the solar panel, not needing to go through the AA power pack.

My question is this. Can I patch into the AA battery recharger and instead charge some D cell batteries with it? I can buy D cells with 9000 mAh, instead of using AAs with 2700 mAh. If so, wouldn't I be able to leave my solar panel out in the sun for longer, basically saving up electricity all day long, instead of for just a few hours like I do with AA batteries? My solar panel supplies 422 mAh, so a 9000 mAh battery would take a few days to fill, right?

I know, you're going to say, just buy some deep cycle batteries like they have at the boat store! But I live in Taiwan and we don't have any boat stores, or even hobby shops, that I know of. We do have some golf courses, so maybe I could find golf cart batteries (6 v x 2 = 12 volts). And deep cycle batteries cost a couple hundred dollars, compared to D cells which can run me about $10 each. What I'd really like to get my hands on is rechargeable lantern batteries, 6 v or 12 v.

I've got another solar kit on the way, and I already own a power inverter and charge controller. Until that kit arrives, what do you think, can I clip some D cells into my AA battery recharger and get results?

 

[Noggin]

The D cells are probably multiple AA cells in parallel. You can recharge them as you're saying, provided that the current is roughly a minimum C/(20 hours) (where C is the battery capacity in mAh). So, if your D cell is 9000 mAh, then you'd need 450mA of current to charge them at a trickle charge rate.

Keep in mind that charging batteries is not 100% efficient, so charging your D cells will take longer than 20 hours at a C/20 rate.

 

[audioguru]

Winter is coming. The sun is not very high so its light is not nearly as bright as in summer and sunshine is not for long each day. Behind a window glass the light is half. It might take your solar panel all winter to fully charge huge D cells.

 

[asiaeast]

winter in Taiwan

I know what you mean about winter coming. I'm curious to see how things go at that time.

Right now, I am in solar heaven. Taiwan lies directly on the Tropic of Cancer, which means that 2 days out of the year, the sun points directly at Taiwan. For most of the summer, there is almost no angle at all to the sun overhead. I'm charging AA batteries so fast here that I'm about to run out, and that's all off just a 6 watt panel that I layout on my balcony for 2 or 3 hours a day. As you probably know, due to the tilt of the earth, the sun will be directly over the Tropic of Cancer twice a year.

By the way, thanks for the info about D cells needing 450 mAs to charge. I will soon have about 800 mAs to work with, in mid October. Hopefully I can give it a try and let you all know what happens.

The irony is, just about everything I want to buy is made here in Taiwan, but due to licensing agreements, they can't sell it here. So I have to have it shipped in from the US at about $45 a shot. And when I flip it over, it says, MADE IN TAIWAN. Arrgghhh.....

 

[audioguru]

Here in Canada the sun is almost directly overhead in the middle of summer.
Now it is noticeably lower and the days are noticeably shorter.
In the middle of winter the sun is very low in the sky at noon and daylight is very short.

 

[bountyhunter]

I have never seen a women's toy that uses huge and heavy D-cells. It must be very powerful..

Must be the turbocharged version.

Energizer sells C and D Ni-MH rechargeable cells that have a little AA cell inside.

radio Shack and Digi-Key both used to sell the "full power" NI-CAD cells in both C and D size (not the fakes with a little cell inside). Surprising how heavy they are.

 

[asiaeast]

paydirt

I think I hit paydirt with my battery search. Last night I went to Carrefour, a French owned store here in Taiwan. I bought a nice looking lantern with a sealed lead acid rechargeable battery inside. Now my wife is having kittens because I want to take the lantern apart just to get at the battery. Cost = US$45.

On the battery it says:

6V4.0AH/20HR
Cycle Use 7.20 - 7.50 v
Standby Use 6.75 - 6.90 v
Initial current less than 1.2A

So I plan to buy a second lantern now, to get the second battery that I need. 6v x 2 = 12 v.

I have a charge controller and a power inverter. I'm just waiting for my second solar panel arrive, to give me enough watts the run the charge controller.

So tell me if I've got this right. I hook up the two batteries in series, getting 12 volts. I plug my charge controller in and wait for the batteries to fill up. Then, when full, I unplug the controller and plug in the power inverter, giving me AC.

My two solar panels linked together will give me 12 v 844 mA 12 watts. My charge controller says:

Load 7 A Max
Cut-out 14.2 V
Cut-in 13 V

I know the charge controller needs at least 10 watts to work.

My power inverter needs at least 200 mA to work.

Does that sound like it will work out?

Any precautions I should take?

Look at this post and you can see the white plug that I use to get from 12 V to my hand held devices or AA rechargers (5.5v 500 mA):

Stepping Down: 12 volts to USB | Sun Pod One

 

[asiaeast]

Clip in D Cell

I went to the electronics store and bought the parts for under US$15. It took me a couple minutes to assemble. Basically, I clipped a super D Cell battery into the AAA battery power pack. Since both batteries are 1.2 volts, the idea works. The AAA batteries can only hold 1000 mAs each, but this supper D can hold 9000 mAs. In fact, I passed up on a chance to buy a rechargeable D Cell that can hold 11000 mAs, just because it was a little more expensive than I wanted to pay.

If I understand right, since my solar panel puts out around 433 mA/hour, it would take about 2.5 hours to charge one AAA battery at 1000 mAs.

400 mA x 2.5 = 1000

The 9000 mA battery should take about 22.5 hours to charge.

400 mA x 22.5 = 9000

That means I can leave my solar kit out in the sun for a few days before the battery is full. I get about 6 hours of direct sun on my balcony, and the rest of the day is indirect sunlight.

Why do all this? It's a lot less work if you don't have to keep changing the batteries all the time. In a day, I have to go out and check the solar kit about 2 or 3 times, then switch out the small batteries. Now, I can charge over a longer period of time. Once the D cell is full, I can then recharge just about everything I own from it.

I'm no expert on electroncs, so I'm pretty excited that this idea is working. Of course, only try this at home at your own risk. As far as making it portable, you'd need to make the setup waterproof, probably. And you could always chain more D cells together and store them in your backpack or on your bicycle as your travel around.

Now all we need is for someone to start selling these things in the stores!

See a picture here:

Solar Charging with D Cells | Sun Pod One

 

[fantabulous68]

Yes im a Gal LOL!!!!!!!!!!!!!!!!!!!!!!!!!!!

D cells, DD's, vibrators


Thanks for the laugh...........................
Good way to start my morning....

Happy Heritage Day!!!!

 

[Noggin]

If I understand right, since my solar panel puts out around 433 mA/hour, it would take about 2.5 hours to charge one AAA battery at 1000 mAs.

400 mA x 2.5 = 1000

The 9000 mA battery should take about 22.5 hours to charge.

400 mA x 22.5 = 9000

Only problem is that you're assuming that the charging process is 100% efficient. Add 20-30% (probably don't need to add that much honestly) and you'll be fine. And don't worry about overcharging those D cells with only a 400mA charger, it won't hurt em.

 

[asiaeast]

Only problem is that you're assuming that the charging process is 100% efficient. Add 20-30% (probably don't need to add that much honestly) and you'll be fine. And don't worry about overcharging those D cells with only a 400mA charger, it won't hurt em.

Ok, thanks.

Now the problem occurs to me, how do I get the juice back out? I'm not sure the power pack I'm using is designed to handle 9000 mAs. Usually it holds three AAA batteries at 1000 mAs each. Trickle charging a larger battery works easily, but will reversing the process causing things to flare up, literally?

I guess some of the answer depends on how the power pack is wired, with the batteries in parallel or series, right?

Is it possible to charge batteries in series and discharge them in parallel, and what's the pros and cons of that?

I feel like I just opened a can of worms here....

 

[audioguru]

While charging your battery with the solar panel, how will you stop the sun (the earth) at the noon position?
The current might be 400mA at noon in summer but will be much less at other times.

 

[asiaeast]

While charging your battery with the solar panel, how will you stop the sun (the earth) at the noon position?
The current might be 400mA at noon in summer but will be much less at other times.

I've been to the Arctic Ocean in northern Alaska and seen the sun doing loops around the sky 24 hours a day. It's pretty impressive. What amazes me is that although the growing season is shorter for plants there, the day is longer. Plants don't really care if the sun rises on time or not. When they get sun, they grow. If they get 24 hours of sun, they grow 24 hours a day. Plants don't need to sleep. When you do the math, plants in the far north actually get more daylight per growing season, often growing to sizes much bigger than plants in the lower regions. The same might be true for solar. If you store up enough energy in the summer time, 24 hours a day, it could last all winter. You just have to spend a fortune on batteries.

Since I now live so close to the equator, the position of the sun in the sky has very little effect on my solar projects. I don't even put much thought into that. In the winter, I don't expect much change, because the sun won't go much lower in the sky. It only moves between the equator and the Tropic lines throughout the year, and since I live on the Tropic of Cancer (in Taiwan), solar is idea here.

The more serious problem we face with solar in Taiwan is the crowding. Most people don't know that Taiwan is the second most crowded place on earth. On this tiny island, we have over 23 million people. As a result, almost no one lives in houses, except the rich, and the farmers in the countryside. Everyone stays in high rise building, so there is little roof area to mount any solar on. I just hang my solar out the window, or better yet, I lay it flat on the edge of the balcony.

I am using CIGS solar panels. They are really new material and they don't have any silicon in them. When I put them back to back with the older silicon based solar panels, there's no competition. Even with the sun at a angle, they still pick up and store and ton more energy. Give it a try.

Every part of the world is different. For example, because England is overcast so often, solar is not as effective there. I don't think solar will solve problems everywhere. What I'd like to do next is get a little wind turbine. Because I live on the 20th floor, we often get a lot of wind, especially on overcast days when solar doesn't work so well. Anyone know where I can buy a portable wind turbine, something not too big? Looks like I might have to build something like that someday, since I haven't found one that fits my needs yet.

As far as the Brunton solar kit goes, it says 400 mAs and 12 volts. But in actually testing in direct sunlight, I see it flucuating between 15 volts and 18 volts. Possibly because the sun is so intense here. So at noon it might be producing a lot more than expected, which means during the rest of the day, I'm still doing fine. Whatever the math and the notion about the position of the sun are, in actual use, I'm getting more charge out of a 6.5 watt solar panels than I need. I've filled all my hand-held portable devices (i-pod/cell phone/etc.) 10 AA batteries and 3 AAA batteries. Still we have sunny days and I have nothing left available to charge. That's why now I'm experimenting with moving up to a bigger system, like with the D Cell and the lead-acid battery.

If you go around and recharge all the batteries in your remote controllers (I must have a dozen of them by now), that will last you a year or so. If you recharge all your hand held stuff about twice a week, that will keep those items off the grid, too. Yeah, when you do the math, it's not cost effective and I'm not even putting a tiny dent in the global pollution problem. But hey man, this is just my hobby. And it's teaching me a lot about solar and how a bigger system could work out for an entire house.

 

[audioguru]

I have many solar garden lights. They work fine in the middle of summer and glow all night long.
But now in the fall the sunshine is weak and not for long. They glow for about 2 hours following a sunny day and for only half an hour or less following a cloudy day.
I don't see them glow in the winter.
They are cheap (many were free) so their light output is almost nothing.

 

[asiaeast]

I have many solar garden lights. They work fine in the middle of summer and glow all night long.
But now in the fall the sunshine is weak and not for long. They glow for about 2 hours following a sunny day and for only half an hour or less following a cloudy day.
I don't see them glow in the winter.
They are cheap (many were free) so their light output is almost nothing.

How do you keep people from stealing them? Do you live out in the country? My friend in Seattle bought a lot of them (they were cheap) and slowly they disappeared. I'm pretty sure the wind didn't blow them away... hahahaha.

It would take some work, but you could wire them together like Christmas lights and keep them going all year round from a battery bank. Personally, I'm not the kind of guy who likes to wire stuff up. I'm more the "plug and play" type. However, the more I experiment with electronics stuff, the more hooked I get. In the back of my mind I keep thinking about how to write a patent and make some money off these ideas, too.

Does anyone know anything about writing patents? It looks somewhat complicated (and probably expensive).

 

[audioguru]

How do you keep people from stealing them?

There are no poor people in my city. All the American criminals are in jail. So there is no stealing. Even school kids do not steal solar garden lights.

My electrical utility gave away solar garden lights for free so their value is almost nothing.

 

[mneary]

Where in Canada is the sun almost overhead? Even in Niagara Falls, Ontario at Noon on June 21, the sun would be less than 70 degrees above the horizon.

I guess that's 'almost overhead' if you compare it to 22 degrees above the horizon on Dec. 21.

 

[bryan1]

Well years ago in chat all da gals said they had major trouble keeping their BOB's fully charged. I simply suggested to them to use re-chargables and stop buying new batteries everyday. The things thrown back at me were from marriage proposals to you dirty ol' bugger. By the way a BOB is known as a Battery Operated Boyfriend......

 

[bountyhunter]

Well years ago in chat all da gals said they had major trouble keeping their BOB's fully charged. I simply suggested to them to use re-chargables and stop buying new batteries everyday. The things thrown back at me were from marriage proposals to you dirty ol' bugger. By the way a BOB is known as a Battery Operated Boyfriend......

As Peggy Bundy once said on "married With Children":

"If they could just make a shower massage that could take out the garbage, we wouldn't need men at all..."

 

[asiaeast]

wind turbine

I know this is really off topic for this thread, but so are most of the funny posts about women.

Since we've got two typhoons heading toward Taiwan at the same time right now, with the potential to form one big gangbuster (no, I didn't say gang bang) of a typhoon, I haven't seen much of the sun at all in the last week. So now my thoughts are, why can't I build a wind turbine for the days when it's windy and put it where the sun don't shine? (I mean outside, silly rabbit)

Anyone recommend a good motor I can find just about anywhere? I saw this cool thing online where this guy took PVC pipe and cut blades from it, cause they are curved and will respond to wind pressure.