I was measuring torque required to drive various drill bits and incidentally found that my cordless drill was delivering way less torque than...

I was measuring torque required to drive various drill bits and incidentally found that my cordless drill was delivering way less torque than it was spec'd for. 80in-lbs measured vs 250 spec'd. If this wasn't a Milwaukee drill, I would have dismissed it as a spooky torque spec. But 80 vs 250 for a Milwaukee doesn't figure. The thought that came to me was maybe the battery couldn't de...

Knowing ship owners are the cheapest folk on the planet, it's 100% certain similar calculation have been done before: Vessel displacement: ...

Knowing ship owners are the cheapest folk on the planet, it's 100% certain similar calculation have been done before: Vessel displacement: 1,000 kilo ton (~300 m LOA) Prop power: 80 MW Na-S battery density: 0.150 MW-hr/ton Voyage time: 720 hours 57,600 MW-hrs 80 X 720 / 0.150 = 384 kilotons ~ 38% of the weight of the loaded ship The ship loses about a quarter of it's ca...

I am looking for a formula for calculating the run time of my APC battery system. I did a search but what I found required a particular model...

I am looking for a formula for calculating the run time of my APC battery system. I did a search but what I found required a particular model of apc. Total watts of computer and monitor is about 120 watts. Battery in my apc is 12V 18 Ah Thanks, Andy

I assume everyone has heard of this kid and his clock. http://truthuncensored.net/wp-content/uploads/2015/09/ahmed-mohamed-clock.jpg The...

I assume everyone has heard of this kid and his clock. http://truthuncensored.net/wp-content/uploads/2015/09/ahmed-mohamed-clock.jpg The picture of the clock shows a 9V battery hookup but no battery. That means the kid either had to plug the clock in or it does have batteries that are not shown. If we assume that there are no batteries, can this clock store it's alarm time? I say no, bu...

90% of the electric bill in the desert at this time of the year is HVAC. The rest of the house doesn't need so much power and only requires a...

90% of the electric bill in the desert at this time of the year is HVAC. The rest of the house doesn't need so much power and only requires a small low cost battery for night time. Freeze about 2 tons of water during the day and then sink heat into the ice at night. Maybe 2/3rds of the solar power goes to running the conventional AC or heat pump during the day and 1/4 goes to freezing water...

OT: Solar Charging 12V Car Battery... My son, Aaron, software engineer turned farmer, has acreage in the San Tan Valley with no source of...

OT: Solar Charging 12V Car Battery... My son, Aaron, software engineer turned farmer, has acreage in the San Tan Valley with no source of electric power. He'd like some artificial light for his chicken coop to increase the egg output. Lighting and timers are easy to find off-the-shelf, but I need some pointers toward finding a good quality solar panel that can charge a 12V car batter...

I want to calculate approx run time of a D cell with a capacity of 13,000 Mah. I assume that Time(H) = Capacity(Ah)/Current(A) equals a final...

I want to calculate approx run time of a D cell with a capacity of 13,000 Mah. I assume that Time(H) = Capacity(Ah)/Current(A) equals a final battery voltage of 0 volts which will not work in my case. I need a calculation for an ending voltage of around 2.0 volts. (At 2.0 volts, my clock starts losing time.) Thanks

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http://www.ebay.com/itm/Etinesan-Big-capacity-900mAh-9v-li-ion-lithium-Rechargeable-9-Volt-Batte ry-/390967934161?pt=LH_DefaultDomain_0&hash=item5b07813cd1 Claims the nominal voltage is 8.4 and it's good for 1200 cycles. Made in China by Etinesan. Priced at $9.59 with free shipping. Sounds like a deal to me. --- news://freenews.netfront.net/ - complaints: news@netfront.net ---

A friend has a battery powered Ryobi lawn trimmer ("weed whacker") which doesn't work. The 12vdc wall wart puts out only ~ 12.4v. I charged...

A friend has a battery powered Ryobi lawn trimmer ("weed whacker") which doesn't work. The 12vdc wall wart puts out only ~ 12.4v. I charged the lead-acid gel cell using a car charger. The charge rate (selectable) was 0.5A. Afterward the trimmer seemed to work as new. Can the car charger be used to charge this battery? He can install a timer to limit charge time if that's something req...

I have a solar charging I am using with my car battery. The current voltage of the battery is 12.7 volts. And the charger is still...

I have a solar charging I am using with my car battery. The current voltage of the battery is 12.7 volts. And the charger is still charging. Here are some specs for the charger. Rated power output = 5W Operating power voltage = 18V Operating power current = .33A Trickle charging current = .2A Floating charging Voltage = 13.8 Overcharge Protection Voltage = 14.1 Voltage At what ...

Ok, this is a question that is not so battery-charger specific, but is obviously related. So here's a circuit fragment: 18V ...

Ok, this is a question that is not so battery-charger specific, but is obviously related. So here's a circuit fragment: 18V +----+--------__^------/\/\/-----------+ | 2n3055| 0R5 | | | 5W / | | \ 5R10W | | / |_______|>

Robotic;Notes - Mizuka's death https://www.youtube.com/watch?v=rIoV60cIu7s

Robotic;Notes - Mizuka's death https://www.youtube.com/watch?v=rIoV60cIu7s

In a hardware store, I saw a rectangular bar, 10" long, with two through holes, labeled "MAGNETIZE" and "DEMAGNETIZE". Presumably it has a...

In a hardware store, I saw a rectangular bar, 10" long, with two through holes, labeled "MAGNETIZE" and "DEMAGNETIZE". Presumably it has a battery compartment, though I didn't check. What's inside? -- Rich

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http://blogs.smithsonianmag.com/ideas/2013/12/a-potato-battery-can-light-up-a-room-for-over-a-mo nth/?utm_source=smithsoniantopic&utm_medium=email&utm_campaign=20131208-Weekender

Would the stuff inside ever become an insulator and stop conducting electricity? -- @~@ Remain silent. Nothing from soldiers is...

Would the stuff inside ever become an insulator and stop conducting electricity? -- @~@ Remain silent. Nothing from soldiers is real! / v \ Simplicity is Beauty! May the Force and farces be with you! /( _ )\ (Fedora 15 i686) Linux 3.3.4 ^ ^ 22:50:01 up 6 days 2:36 0 users load average: 0.00 0.01 0.05 不å??貸! 不詐é¨?! 不援交! 不æ??交! 不æ??å?«! 不è?ªæ®º! è«?è?

Cost of solar PV just keeps dropping. Even EV battery costs have dropped 30% in 5 years. Anyone who this fundamental truth will change needs...

Cost of solar PV just keeps dropping. Even EV battery costs have dropped 30% in 5 years. Anyone who this fundamental truth will change needs to join a drinking club, i.e., the "Man will Never Fly" society. Bret Cahill

I was thinking about making a little battery powered strobe using one of the really bright white LEDs now available. But I don't know how long...

I was thinking about making a little battery powered strobe using one of the really bright white LEDs now available. But I don't know how long the phosphor glows after the LED turns off. Anybody here know? Thanks, Eric

This is from a cordless phone. I think it is a speaker. Phone uses 2.4 volt battery. I was wondering if it would work in a 9 Vdc...

This is from a cordless phone. I think it is a speaker. Phone uses 2.4 volt battery. I was wondering if it would work in a 9 Vdc circuit? https://www.dropbox.com/s/yy6rwm0vib91010/PhoneSpeaker.jpg?dl=0

Hello all, Can anyone ID the component in the picture with the marking FD218-3055?? Or is there an alternative replacement for the...

Hello all, Can anyone ID the component in the picture with the marking FD218-3055?? Or is there an alternative replacement for the device. It is part of a battery charging circuit. As you can see the one on the left popped it top and let the smoke out. https://www.dropbox.com/s/y1b6hzhh47w583p/Component%20ID.jpg?dl=0 Thanks, Les

Hi, What is the simplest (cheapest, lowest energy) way to get an LED to light if the circuit from a 1.5v battery is broken? Thanks, Rod

Hi, What is the simplest (cheapest, lowest energy) way to get an LED to light if the circuit from a 1.5v battery is broken? Thanks, Rod