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    Falling Battery Prices ....

    Here's an interesting chart I stumbled upon !! Solar panels also show a similar curve!
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    Makita Battery 18V 5Ahrs

    I've just bought a heavy duty grass trimmer ...runs on two if these .... Someone on Youtube has broken one open and they contain 10 Sony cells .... we can assume they're 2500mAHr cells , since Makita also have the same pack in 3 , 4 and 6 Ahr ... These packs are on ebay at $15.6each...
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    A totally new concept in electricity Storage

    "The energy storage industry is all about incremental improvements, so its rare to see a product come to market that does something radically different. That happened last week when the stealthy Swiss/Southern Californian startup Energy Vault went public with an unusually creative grid storage...
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    Exposed ...Ultrafire and other brands are recycled cells !

    This is a good video , the uploader has discovered what I found out2 years ago , that Chinese unbranded cells are recycled from expired battery packs .. At 8:30 he removes the end caps to expose the spot welding marks ...
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    Global (solar panel) PV module prices collapse

    Global PV module prices collapse The predicted fall in global PV module prices appears to have already begun, with PVInsights and EnergyTrend reporting average prices in the $0.27-$0.37/W range.... Current U.S. prices are higher, due to new tariffs ... However prices appear to be falling in...
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    recycling li-ion .... the price of cobalt

    The price of cobalt has gone up fourfold over the past few years ... now at 100/Kg and all indications are it will not come down ... Li-ion cells contain 18% by weight of Co ...value of Co in one 18650 is $0.81 ... (in additionthere is metallic copper foil 5 gms per cell and aluminium foil, and...
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    When powerwalls fade and die

    Powerwalls made from recycled cells must presumably at some point become unusable ... How does this become apparent ?? Do cells start toself discharge , or have such a high internal resistance they waste too much powerand get hot ? .... can these cells be isolated and removed?? How many cycles...
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    Making use of surplus power ...HHO ...electrolysis.

    I think a few here maybe in the same situation I'm in ... Those living off grid will use solar to charge a powerwall ... but when the battery isfull what to do with excess energy still being produced by the solar panels??? I know I have a lot that goes unused .... electrolysis !! Looking on...
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    How to make a cell spot welder in 5mins ... zero cost

    You need a short length of twin wire house wiring cable ...I used some twin 4mm square (each wire 4square mm)...thicker wire would be better ,but eventwin 2.5mm square might be OK .. Removethe plastic insulation from one end,Only 10mm ...so now you have the cable with two wires protruding 10mm...
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    Internal Resistance of cells ..

    Internal resistance gives an indication of how efficient a cell (or battery) will be in giving back what you put in . If 1WHr of electricity is put into two separate cells, the one with low resistance will give back more of that energy ... the one with higher resistance will waste more in...
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    Ultrafire and Trustfire cells

    Over a year ago I bought ten ultrafire 18650's from eBay ... the price was so good , and I actually believed the promised rating of 3800mAHrs ... lol ... I never used them , and recently I started to examinethem .. From the outsidethey all look the same ... but their weight varies , their...
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    Speeding up measuring the capacity of cells .

    A lengthy part of our process is measuring the AHr capacity of each cell ...It seems everybody does this , then writes the capacity to the nearest mAHr !! on the side of the cell , then puts them in bins for latter use . We don't really need great accuracy in this, since some will divide all...
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    Tesla launches powerwall 2

    Full article here ....https://www.pv-magazine.com/2017/03/09/tesla-launches-powerwall-2-says-all-solar-homes-will-have-storage/ "....said he expected that, within the next 10 years, 100% of homes with rooftop solar would also have battery storage....a 30% smaller, sleeker unit the new design...
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    What to do with all the POWER

    Some firewallers are sitting on some very serious power !!!! Some maybe even able to pulse ....ONE MEGAWATT!!! ... With that sort of capability (even with a lot less) you can do some very interesting things .... 1. .... Get yourself or pets airborne ... see "Ducted fans " on Ebay , used for...
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    Temperature rise in powerwalls and cell packs

    I recently watched this 3 min video by Damian ...http://ashtangapictureproject.com/wp-content/uploads/2014/10/dwipadasirsasana159.jpg He's building a 20s10p pack for a road vehicle and at first sight it seems quite wrong ... he's hot glueing the cells in a very tight pack , and shrink wrapping...
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    Replacing car lead acid battery with 18650's

    I'm sure someone here must have done this .... A slight challenge with the voltage range ... 3 or 4 cell blocks ? Some trucks use 24V I think ...this would be much easier ... 7 cell blocks is just right.
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    Using leds for balancing

    Leds have a threshold voltage voltage below which they draw no current ... This allows them to be wired across cells , if the voltage of the cell is (say) 3.8 , no current is drawn , no light emitted .As the cell is charged up and the voltage gets to 3.9 , light is seen and a small current...
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    Is it necessary to test capacity of each cell?

    I'm fairly new to this , so brainstorming an idea which may be wrong .... It seems a lengthy part of the procedure is to test the capacity of each cell and sort them accordingly ... if using these cells for a powerwallit seems sensible to use all , even those with 1/2 AHr .... but it...
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    Fuses and busbars

    Hi everyone ....New member here .... I've only recently become aware of the 18650 scene ....I'm sure it holds great promise , I've spent most of my life tinkering with electronics , playing with leds , making solar panels , so I hope I can offer some new insights , and also learn a lot from this...
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