Search found 9 matches

by kc8adu
Nov 20 2016 3:47pm
Forum: Alternative Energy
Topic: Archimedes screw turbine control for off-grid generators
Replies: 17
Views: 3245

Re: Archimedes screw turbine control for off-grid generators

i would also use a pm generator head. much easier to regulate and a dc-dc converter is easier and safer than a flywheel and governor. the alternator wants to be run at 3600 rpm to get its rated voltage and frequency. and the dc genrerator is easy to prevent runaway.just switch in a diversion load in...
by kc8adu
Nov 14 2016 8:35am
Forum: Battery Technology
Topic: ac batteries at walmart
Replies: 2
Views: 599

ac batteries at walmart

ac battery1.jpg
ac battery1.jpg (242.02 KiB) Viewed 235 times
shelf tags reads same.
btw these were on blowout sale recently.
so there we have it.18500 3.7v=1000mhz
18650 3.7v=2000mhz.
direct chemical to rf conversion.
and at walmart.
by kc8adu
Nov 13 2016 3:51pm
Forum: Battery Technology
Topic: anyplace to buy 21700 cells yet?
Replies: 3
Views: 591

Re: anyplace to buy 21700 cells yet?

they are an unknown at this point till we get hands on with them.
some of the datasheets which are preliminary show ok for 20a bursts.
but they are unicorns for all practical purposes.
till i can order some and test.
by kc8adu
Nov 13 2016 2:03pm
Forum: Alternative Energy
Topic: Using a Computer UPS as a Solar Inverter
Replies: 19
Views: 4201

Re: Using a Computer UPS as a Solar Inverter

had some compaq branded 3kva 48v units that were great.oem is deltec.
saw some recently on govdeals but you have to buy by the palletload.
dark startable too.
thats important when using them for an inverter.
by kc8adu
Nov 13 2016 10:56am
Forum: Battery Technology
Topic: Let me know your oppinion about these Chinese 18650 cells
Replies: 9
Views: 840

Re: Let me know your oppinion about these Chinese 18650 cell

common in power tool packs. when rebuilding packs i save the sleeves and put them on the new cells. important if the tool is at stall and the operator(not me)holds the trigger. i have measured in excess of 100a in this condition.while it wont help with preventing damage it may delay an "oh shit!" ev...
by kc8adu
Nov 13 2016 10:51am
Forum: Battery Technology
Topic: Lishen 18650 cells and the death of disposables
Replies: 4
Views: 711

Re: Lishen 18650 cells and the death of disposables

most devices here are modded to accept 18650. those that are not feasible to mod are dumped at the flea or garage sale.or used to dispose of any alkaleaks i happen to get. aa and aaa that come with devices i mod go in the battery box at the shop for remotes to the tv's i refurb and sell. while the d...
by kc8adu
Nov 13 2016 9:44am
Forum: Battery Technology
Topic: anyplace to buy 21700 cells yet?
Replies: 3
Views: 591

anyplace to buy 21700 cells yet?

seems these would be great in the versapak sticks.
and possibly some flashlights.
by kc8adu
Nov 13 2016 8:47am
Forum: Battery Technology
Topic: Let me know your oppinion about these Chinese 18650 cells
Replies: 9
Views: 840

Re: Let me know your oppinion about these Chinese 18650 cell

the cardboard is actually better than shrinkwrap. at severe high temp shrinkwrap melts exposing the can.leads to shorts,thermal runaway,and a violent failure. takes much higher temps to destroy the cardboard and if that happens you already have a much bigger problem between your legs and should have...
by kc8adu
Nov 12 2016 9:12am
Forum: Alternative Energy
Topic: Using a Computer UPS as a Solar Inverter
Replies: 19
Views: 4201

Re: Using a Computer UPS as a Solar Inverter

yes a quality ups makes a nice solar inverter.been doing that here last 25 years. i saw the modding being done to the mosfets,shunt,ect. i would not bother. see the mfr uses that same board for the whole line from 1kva to 3kva. and populate to suit. all you will do is blow it up when the undersized ...