The power/solar/batteries/generator thread

[Irving]

I've noticed that every new phone I get has better and better battery life, and seems to take less and less time to charge. Would it be difficult to retrofit a cell battery to power some led flashlight head?

[68Charger]

I've noticed that every new phone I get has better and better battery life, and seems to take less and less time to charge. Would it be difficult to retrofit a cell battery to power some led flashlight head?

that part is not too difficult- but you have to make sure the voltage of the battery doesn't go below a certain level- so you can't just hook it up & go, there does have to be some thought to it, or the battery won't take a charge again..

also, the recharging is more tricky with Li-Ion batteries.. just make sure the charger you're using is intended for Li-Ion batteries

[Irving]

Well, wouldn't you just set it up to use your cell charger?

I'm interested in what you said about the voltage level. What is the difference between running the battery down till it won't turn on while it is powering a cell phone, or powering a light?

[68Charger]

Well, wouldn't you just set it up to use your cell charger?

I'm interested in what you said about the voltage level. What is the difference between running the battery down till it won't turn on while it is powering a cell phone, or powering a light?

you could certainly use your cell charger-

the minimum voltage has to do with the chemistry of Li-Ion batteries..

a quote from http://www.batteryuniversity.com/partone-12.htm

"Extreme low voltage must also be prevented. The safety circuit is designed to cut off the current path if the battery is inadvertently discharged below 2.50V/cell. At this voltage, most circuits render the battery unserviceable and a recharge on a regular charger is not possible.
There are several safeguards to prevent excessive discharge. The equipment protects the battery by cutting off when the cell reaches 2.7 to 3.0V/cell. Battery manufacturers ship the batteries with a 40% charge to allow some self-discharge during storage. Advanced batteries contain a wake-up feature in which the protection circuit only starts to draw current after the battery has been activated with a brief charge. This allows prolonged storage."

this is a safety feature because:

"If the cells have dwelled at 1.5V/cell and lower for a few days, however, a recharge should be avoided. Copper shunts may have formed inside the cells, leading a partial or total electrical short. The cell becomes unstable. Charging such a battery would cause excessive heat and safety could not be assured. "

so what's the worst that could happen?

http://www.youtube.com/watch?v=WeWq6rWzChw

[jerrymrc]

Solar panels. Here is the link for my first ones I did. http://www.falfiles.com/forums/showt...hreadid=215773

There have been some minor changes since then. I now place a desiccant at each end and drill a small hole at each end. I then draw a vacuum to make sure the panel is sealed. If no leaks I flood the panel with Nitrogen and seal it back up. This has stopped the fogging issues.

Now you can run the panels on just the board with no gasket/glass but they are a "good weather" only config. Cells are still cheap from the supplier I listed. I have to finish the other 3 panels for the camper. I also have 100W or so for the garage that are still going after 5 years.

Too many projects, too little time.

[jerrymrc]

Let's talk Batteries. Ya need them. Ya need rechargeables. ya need a charger. The cheap Harbor Freight ones are marginal. Let me rephrase that. The NiMh are marginal, the NiCd's are worthless.

Buy or build a solar charger. Buy AAA and AA batteries. If ya need C's and D's buy the tubes to convert the AA ones (and test them). Batteries, batteries, batteries. If your planning on taking this game more than 30 days heed the above paragraph.

Experience has taught me that the duracell ones work and last great. There not cheap but they last and you can have many stored since the life of a rechargeable starts when ya first charge it. Life is 1-2 years once you start charging them.

I keep looking at the eneloop's. I keep hearing both good and bad. For those that may not know here is the scoop on rechargeables. When you charge a NiMh you get 100%. come back in 6 months and it is down to like 60%. The eneloop's will retain 85% after a year.

So this is the deal. Ya charge and ya use. charging a second set to be used within 30 days is OK. If ya want to charge and keep.... I have heard that some people get a short life out of there eneloops. I have none at present.

I keep a good stock of unopened rechargables on hand along with two kinds of chargers.

Just a thought gang.

[Beprepared]

you could certainly use your cell charger-

the minimum voltage has to do with the chemistry of Li-Ion batteries..

a quote from http://www.batteryuniversity.com/partone-12.htm

"Extreme low voltage must also be prevented. The safety circuit is designed to cut off the current path if the battery is inadvertently discharged below 2.50V/cell. At this voltage, most circuits render the battery unserviceable and a recharge on a regular charger is not possible.
There are several safeguards to prevent excessive discharge. The equipment protects the battery by cutting off when the cell reaches 2.7 to 3.0V/cell. Battery manufacturers ship the batteries with a 40% charge to allow some self-discharge during storage. Advanced batteries contain a wake-up feature in which the protection circuit only starts to draw current after the battery has been activated with a brief charge. This allows prolonged storage."

this is a safety feature because:

"If the cells have dwelled at 1.5V/cell and lower for a few days, however, a recharge should be avoided. Copper shunts may have formed inside the cells, leading a partial or total electrical short. The cell becomes unstable. Charging such a battery would cause excessive heat and safety could not be assured. "

so what's the worst that could happen?

http://www.youtube.com/watch?v=WeWq6rWzChw

"Extreme low voltage must also be prevented. The safety circuit is designed to cut off the current path if the battery is inadvertently discharged below 2.50V/cell. At this voltage, most circuits render the battery unserviceable and a recharge on a regular charger is not possible.

Interesting about the Li-Ion. With a safety circuit inside, would this leave the battery unusable in the unlikely event of an EMP pulse? Also could used hybrid car battery (gotta be good for something) be used for home needs (If the voltage and charging was right)?

[ronaldrwl]

I would definitely be interested in learning/seeing solar power systems.

I just looked into this. Harbor Freight has a system that sells for around $200 or something. That got me interested. So, my son and I went through the calculations. Under very good conditions it would take 7 years to pay for itself (as I remember).

Very disapointing. I wanted to see if I could run my computers durring the day by solar. It would take thousands of dollars to set up and would never pay for itself.

Bummer

.

[jerrymrc]

I just looked into this. Harbor Freight has a system that sells for around $200 or something. That got me interested. So, my son and I went through the calculations. Under very good conditions it would take 7 years to pay for itself (as I remember).

Very disapointing. I wanted to see if I could run my computers durring the day by solar. It would take thousands of dollars to set up and would never pay for itself.

Bummer

.

I built the first two panels that make 70 watts for just over $100. Add a charge controller for $30..... In my case I run 1/2 the garage off of a 60W panel and the bank of gel cells.

While the solar is not dirt cheap you have to have something to provide power some way.

More thoughts on this. Most people just throw away there UPS when the batteries go bad. These can be used as cheap inverters. I have a couple that I have rescued and use them. One thing you will have to do on most of them is disable the alarm. First pic is the back up for the pellet stove. Rescued 600W UPS with 110Ah of gel attached. Second is the garage power system. Panel is in the window facing south. This is mainly a winter system so all is good. just some thoughts.

[theGinsue]

My best friend bought a 70watt solar panel from a camoer store a few years ago. It does a great job for charging his camper during MOST days. The problem is that the panel alone cost him $800.

This same guy also bought the Harbor Freight $200 setup. If it's the same one, this uses 3 panels that come up to about 50 watts total. They don't work nearly as well as the $800 panel, but you're still saving $600.

Because of this, I jumped on Jerry's idea of building your own solar panels. His plan is SO much cheaper. I had been planning on building a few of these during this winter. Haven't gotten to it yet.