48 DCV battery design

Hi to all !

I have connected 19 "small" homemade batteries into one realy, realy huge battery. After some tests and after fixing some problems with volmeter, i have this situation:

One "small" battery: DCV : 2,53 V DCAmps: : 0,5 mA

Huge battery: DCV : 48V DCAmps : 24 mA

Hardware:

- 48 DCV homemade battery

- 1KW DC/AC converter

Idea: To pull 1KW from the inverter, for 10 hours.

Methods to encrease power: Step - down Charge pump (?). Capacitors

Calculations:

P 1428 W Ibat. = --- = -------- ~ 30 amperes E 48V

------------------------------------------------ P 1000W I = --- = ---------- ~ 4,5 amperes E 220V

------------------------------------------------- Pout 1000W Pinverter = ------ = ---------- ~ 1428 watts Eff 0.7

------------------------------------------------- C = It = 30A *10hr = 300 ampere - hours.

Questions:

1.) How to produce so much power ( 30A)

2.) Is there possibility to fill the capacitors and then to pull the power from them ( for 10 hours). ?

Conclusion: I have conected two devices ( volt and amper meter ) on the same battery wires, to measure the states on small battery. When i switch to power measurment (on ampermeter ) my voltmeter shows 350mV and my amp. meter, 0.5mA. After i shut down amp. meter, voltage on the voltmeter shows again 2,5 Volts.

Mark

Reply to
mark2006
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There's no way the home builder can build batteries that will provide the amount of power that you're seeking.

Think bigger; much, much BIGGER!

A typical automobile battery ($50US)might provide 30 amps at 12 volts for something over an hour (battery with 20 hour rating of 55AH, derated for higher discharge rate). 8 or 10 of these batteries in parallel (not a great design) could provide power for 10 hours ($400US to $500US), but multiply the number of batteries by 4 to get 48 volts ($1600US to $2000US). Since automobile batteries are not designed for continuous or deep discharge, you would need to use deep discharge rated batteries (higher capacity, so fewer batteries) but at 2 to 4 times the price of the car battery (maybe $4000US)

Do some online research on wind and solar powered homes. Learn how much battery capacity is available in various formats.

  1. Do you have appropriate space (size, ventilation) for that much battery plant?
  2. Can your floor support that much weight (40 - 100lb per battery)?
  3. Do you have 00 or more to invest?
  4. Unless you have a "free" source (wind, solar, hydroelectric) for charging the batteries, there seems little value in building this size plant. Pedalling a bicyle to drive a generator doesn't count - that's a source of maybe 200 watts for a short period.

On the other hand, a 5KW gasoline powered generator with an advertised run time of 10 hours (at half load) on 4 gallons of gas is $499US. That's a small fraction of the cost of building a battery plant to provide the amount of power you described.

My qualifications? 32 years in various technical/support roles with AT&T.

John

Reply to
John

I've always wondered why a bike hooked up to an alternator/dynamo with fat children on it peddling wouldn't work?

Reply to
Aly

--
Forget it.
Reply to
John Fields

Average person is good for maybe 200 watts for 15 to 20 minutes. Athletic person can do more power and/or longer time, but probably no more than 300 watts for 25 to 30 minutes. (This assumes an efficient permanent magnet generator, not an automobile alternator.)

If you have enough children (bicycle built for 6 or 8?), a method of combining multpile pedalling speeds into a common load (none of the kids will be exactly matched in ability to the others), and an incentive that keeps them on task - it might work...

John

Reply to
John

fat

Just long enough to watch an episode of Futurama or The Simpsons.

All of this talk of environmental polution, nuclear power, wind turbines, and solar power.

Just stick the fat kids on the power bikes in the garden. It'd probably work in Iran, but let's not go there. They're not fat, unfit, and have an addiction to Big Macs.

I can manage 60-minutes on a cross country trainer which is pretty intense.

60-minutes peddling hard on a bike can be done but more like about 20-minutes as you say.

:)

Reply to
Aly

On 29 Sep 2006 02:02:23 -0700, in message , "mark2006" scribed:

I believe your math is a bit off. It would take 912 (not 19) 2.53V .5mA cells to make a 48V 24mA battery. To wit:

48V * 24mA = 1152VA

2.53V * 0.5mA * 19 = 24.035VA

1152VA / 24VA = 48

So you need 48 columns of 19 rows of 2.5V .5mA cells. Only 47 more to go. Keep us posted.

Reply to
Alan B

:-))))))) I didn't laugh so much for some time J. Holly shit, now i have to sing =ABwith tears in my eyes =AB. The fat kid, the bike, 6-8 kids, the mcDonalds etc. :-))

I've always wondered why a bike hooked up to an dynamo with fat children on it peddling wouldn't work? :-)))))))))))

Just stick the fat kids on the power bikes in the garden. It'd probably work in Iran, but let's not go there. :-)))))))))))

Becuse i am european and catolic i could find some good german girls over 150 kg and tell them that this pedalling is for spirutual enlighment and for waste of fat :-))

//-------------------------------------------------------------------------=

----- Anyway, back to the problem...

The enlightment:

*** The battery is big in design (48 V) but its really light (don't have to worry about the floor :))

Do you have $4000 or more to invest?

***The design is rather simple and i dont have much costs.

charging the batteries

*** I have solar panel for this purpose //-------------------------------------------------------------------------=

--------

Second enlightment : I have changed the design and now i have 1 DCV and 1,2 miliAmps small battery (cell). I conected two small battery's and i get 2 DCV and 2,1 miliAmps.

Tests: If i connect additional two ( all togehter 4 ) i get 4 DCV on 4,15 miliAmps. If i connect cell to voltmeter and if i measure discharge of that cell, then the total discharge ( with voltmeter resistor ) would be 14 days.

//-------------------------------------------------------------------------=

---------- Question is still the same: How would you encrease the needed power ? What do you think of the capasitor idea ?

Mark

p=2Es. OK, this looks like =ABunpossible=BB project but i will not give up... So keep that optimistic spirit and please give me answers to my questions. Keep cool :-))

Reply to
mark2006

any idea / suggestions / comments ?

Mark

Reply to
mark2006

If you want to run a 1KW 48 volt inverter, you will need a battery that will deliver 25 amps or more, for as long as you want to run the inverter - your home-brew cells are totally inadequate for the task, and you can't do anything with capacitors or other things to make it work.

--
Peter Bennett VE7CEI 
email: peterbb4 (at) interchange.ubc.ca        
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Reply to
Peter Bennett

Did you say *homemade* batteries? What are you making them from? Lemons?

Well, even if you have 48V (that's a lot of lemons with nails sticking out of them), at 0.024 A, that's a whopping one Watt of power you're producing. (Ok, 1,15 W.)

You need a battery array about a thousand times bigger to run a 1kW inverter.

Why not make a one-watt inverter?

Reply to
mrdarrett

On 3 Oct 2006 01:20:56 -0700, in message , "mark2006" scribed:

Yes. Read what I posted before, which should help you realize that you cannot square capacity by doubling cells. Unless, of course, the factor is two, which in this case, it is not.

Reply to
Alan B

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