New Power Source for Polywell?

KitemanSA · Post by **KitemanSA** » Thu Mar 12, 2009 8:19 pm

Greetings,
Might these be a good power source for a small scale "continuous" Polywell?

http://www.nature.com/news/2009/090311/ ... 9.156.html

D Tibbets · Post by **D Tibbets** » Thu Mar 12, 2009 9:36 pm

Maby? Appears to be a way to increase the charge/ discharge cycle in lithium bateries. But I'm guessing they would still be way to slow to to be used as capaciters. In mobile applications like electric cars they would be benificial, but in a static application a larger bank of lead acid car bateries would be much cheaper. And, to charge the batteries at a faster rate, you need corespondingly higher power chargers.

Dan Tibbets

Roger · Post by **Roger** » Mon Mar 16, 2009 4:23 pm

D Tibbets wrote: And, to charge the batteries at a faster rate, you need correspondingly higher power chargers.

Dan Tibbets

Yup, I have witnessed this in the Radio Control Hobby. A nice charger for Ni-Cads was $40, Fast charg a 1500ma battery in 15 minutes. Then the 2000ma Nicads came out.....Then the N-Mh batts came out, 2000ma then 2300ma.
Nowadays a nice Li poly charger is $200-$300, batteries are 2000ma to 3000ma now. Chargers use micro processors to manage charging, cells get balanced.

The neat thing about Li poly is compared to Nicads, they can be charged very fast, 3000 milli amps in just a few minutes. (Well, less than 15 minutes. compared to 1500ma Nicads.

Plus N-Mh needs to be stored in a semi charged state and monitored. Failure to maintain the N-Mh properly causes premature failure.

KitemanSA · Post by **KitemanSA** » Mon Mar 16, 2009 8:50 pm

D Tibbets wrote:Maby? Appears to be a way to increase the charge/ discharge cycle in lithium bateries. But I'm guessing they would still be way to slow to to be used as capaciters. In mobile applications like electric cars they would be benificial, but in a static application a larger bank of lead acid car bateries would be much cheaper. And, to charge the batteries at a faster rate, you need corespondingly higher power chargers.
Dan Tibbets

Sorry the link is worthless now. I should have copied the relavent parts and posted them here. The part I was interested in was the 9 second discharge capability. No, this isn't a capacitor, but it may provide good power for a cryo-copper MaGrid. Could run "steady-state" for ~9 seconds with very limited base load power requirements. This may be semi-pro level power at hobby level prices.

D Tibbets · Post by **D Tibbets** » Tue Mar 17, 2009 12:26 am

Hmm... 10,000 AA lithuim batteries (2000mA each (probably more)) would give 10,000 amps (at 1.5 V)for 2 seconds if they could discharge fast enough.
Car lead acid batteries, each with 500 cold cranking amps, would require 20 batteries to do the same (at 12V), except they could probably run over 5-10 times longer. Costs should heavily faver the lead acid car batteries.

I don't know how many volts would be required to drive that many amps through a cooled copper wire, but the 12 volt car batteries would have the advantage here.

I'm unsure why EMC used capaciters to drive the magnets, unless thier low budget scrounging obtained the capaciters at a cheaper price than the required number of car bateries (which I believe they used to drive thier electron guns).

Dan Tibbets

choff · Post by **choff** » Tue Mar 17, 2009 5:10 am

I recall something about rv batteries being used.

D Tibbets · Post by **D Tibbets** » Tue Mar 17, 2009 7:35 am

choff wrote:I recall something about rv batteries being used.

I think you may be right. RV or deep cycle batteries can be discharged to a lower level repeatedly without damage that can occur in car or starter batteries, but they cannot give as much maximum power, so in the given example maby 25-40( or more?) batteries might be needed.

http://www.windsun.com/Batteries/Battery_FAQ.htm

Dan Tibbets

KitemanSA · Post by **KitemanSA** » Tue Mar 17, 2009 3:53 pm

I do wish I had saved that article, but from what I remember, the claim was that the battery could efficiently dump in 9 seconds all the energy that a battery the capacity of a typical Li AA could dump in the 15-30 minutes one usually gets. If this is the case, we are talking not 10,000 but more like 50 to 100. That seems a reasonable power pack, no?

Heck, even at $20 per battery, I could afford that!

Mike Holmes · Post by **Mike Holmes** » Tue Mar 17, 2009 6:30 pm

The bright boys at MIT seem to have a solution: http://www.sciencedaily.com/releases/20 ... 153408.htm

Mike

KitemanSA · Post by **KitemanSA** » Tue Mar 17, 2009 8:13 pm

Mike Holmes wrote:The bright boys at MIT seem to have a solution: http://www.sciencedaily.com/releases/20 ... 153408.htm

Mike

That is the same battery I noted at the intro. Unfortunately, my source hides the article after a few days. I think I will look for better sources from now on.