View Single Post
  #114   Report Post  
Posted to rec.crafts.metalworking
Larry Jaques[_4_] Larry Jaques[_4_] is offline
external usenet poster
 
Posts: 9,025
Default No Gorbal warming...in...58 yrs....

On Sat, 12 Mar 2016 12:18:32 -0500, "Jim Wilkins"
wrote:

"Larry Jaques" wrote in message
.. .
On Fri, 11 Mar 2016 20:20:05 -0500, "Jim Wilkins"
wrote:

"Larry Jaques" wrote in message
news On Thu, 10 Mar 2016 19:25:29 -0500, "Jim Wilkins"
wrote:



That's a case where I think the economics favor grid power, because
of
the high cost and limited cycle life of vented deep-cycle batteries.


That it does, but what happens when (not if) the grid goes tits-up?


We return to the 1800's and DIY steam power, the Good Old Days. But I
suspect that a deteriorating, unreliable electricity supply as in
India would switch the helplessly codependent Greenies from blocking
construction to screaming about their NEEDS!! before it did more than
annoy the more technically competent of us. This neighborhood bands
together and shares resources, one generator serves three houses. I
contribute 100' extension cords and repairs to carbs and electrical
systems, and one of my Coleman gennys has spent almost its entire
operating life powering the house across the street.


Perhaps Gunner's Cull will "reduce" the Green needs. wink



https://en.wikipedia.org/wiki/2012_India_blackouts
"The nation suffers from frequent power outages that last as long as
10 hours."

How often are you equalizing? The last article I read said that it
drops battery life considerably if you do it very often. I think
the
article was in HomePower mag. No equalization can drop the life,
too,
so there's a balance.


Every manufacturer's advice is slightly different, and a battery's
behavor changes as it ages. I think the least damaging method that's
still adequate is to charge at 1% to 2% of the 20-hour-rate capacity
until the voltage rises to 14.8V for flooded or whatever the maker
says for AGMs. I charge unmarked ones to 14.4V at less than half an
amp.


OK.


Usually I use an unregulated rectifier + capacitor charger adjusted to
the individual battery with a Variac. The cap I added to the charger
stabilizes the voltage and current meter readings. "Dumb" rectifier
chargers automatically taper down the current as the voltage rises.
The next time I walk by I check the meters and turn up the Variac.


More automation, I see.


One is a 1970's Schauer charger with a small 3 Amp Variac added in,
the other a homebrew that puts out 0 - 35V at up to 15A, with a 1/10
Farad filter cap. Since they don't have an output regulator they
aren't susceptible to damage from battery voltage being fed back into
the unpowered circuit if the AC is interrupted. You can protect a lab
supply from that with a series diode but then the voltmeter will be
useless.


Useless or merely off by .3v?


I don't equalize vehicle batteries very hard unless the hydrometer or
charging behavior reveals a weak cell. The smaller colored-bead type
is enough to show significant differences and works better on small
riding mower batteries with small caps and little free liquid..


I've forgotten to ask about your battery stack. Whatcha got?


If they are sulfated / corroded / whatever and won't accept current at
14.4V I apply 15V to 16V and keep an eye on the current, which is
typically under 100mA until they start to recover, then it rises and
may need to be limited due to the otherwise excessive charging
voltage. This is the case where a Smart Charger gives up, but a smart
user can salvage the battery. These numbers are all from makers' data
sheets. I just pick the more conservative ones and procedures that can
safely be left unattended.


What kind of new life do you get from the salvaged batts?


My 5-year-old HF '45W' kit supplies 0.6A per panel, making it good
current-limited source for gently conditioning batteries. I made an
LM350 variable regulator to fine-tune the charging voltage and
current. An LM338 will pass more current, I chose the LM350 to protect
some nice 3A meters I found.
http://www.eleccircuit.com/adjustabl...a-using-lm338/
D1 protects IC1 from higher voltage on the output than input, as I
mentioned above.


I picked up some LM317s + heatsinks cheap, and was thinking about the
same use.


Active, adjustable current limiting is conspicuously absent from
commercial battery chargers. I've read that "Pulse" desulfating is
really only a cheap substitute for building in a current limiter. At
Segway I learned how to use a lab-type adjustable power supply to meet
almost any battery charging requirement except fast-charging NiCd and
NiMH. The problem is that it requires a careful, attentive and well
informed user such as an electronic lab technician, NOT the average
mechanical engineer.


g


stratified electrolyte by bubbling. That's one of those inconvenient
solutions only the inventer would tolerate, and impractical for
batteries heavier than Group 31.


Why not vent them well rather than schlepping? MUCH less work.
Enclosed battery space, right? Fan on the inside, window to the
outside? For a more exciting removal of the hydrogen, just burn it
off. (Disclaimer: Kids, don't try this at home.)


When I rebuild the tool shed I plan to leave space for battery shelves
in a separate cabinet on an outside wall. I've had too much trouble
containing liquids like hydraulic fluid to assume I could safely
control invisible hydrogen. I don't have or plan to acquire nearly
enough batteries to fill it so the remaining space will probably be
for lawn and garden chemicals.


I have an old fridge for chemicals.


How much of an actual problem has the temperature swing been for you?
Batteries work well enough outdoors in cars here, where the temps run
from +100F to -10F. When I lived an hour further north it sometimes
dropped to -30F.


No problems, but I'm not heavily using the batteries, nor am I
carefully monitoring their capacities. Not a prob, I don't think.
Temps (most years) run 20-109F, with (every few years) a few days down
to 5F. I've had one burst pipe (outside plumbing, valved!) and one
freezeup (4 hours of portable 1.5KW heater under house fixed that) in
the 14 years I've been here. The first damage I get in plumbing in
the future, I'll replace all the old galv pipe with PEX and put foam
insulation around all of it, for good measure. It won't burst again.
I'd likely get a better flow, too. Pipes are ca 1967.


Being able to watch and limit the charging current spares me from the
uncertainties of voltage-controlled charging. I use the
voltage-vs-temperature table only to determine state of charge and
know when they are fully topped off..


OK. Do you do full-lot, batches, or individual battery charging?


Good idea. Generators are also more costly than grid power.


I once figured about half a buck per KWH. My system is for standy use
only, but I need to test it and exercise the generators.


Solar used to be 25-cents/kWh, but is less now. I'm figuring a cost
of about a buck a watt for purchase of the system, so I'll need to get
$3k together for the systems I want.

One quote for south-facing flat panel setup:
Here in GP, 1.8KW of panels will produce 2,277KWH annually, about
$0.05/KW over a 25 year lifetime. Hmm, forgot replacement batteries
($2k): $0.10 per. No gas purchase/storage/fumes/refills, no rebuilds,
no tuneups, just pure energy. I love the simplicity of solar.


The Interstate battery I put in the truck in 2002 receives a top-off
charge every month or two and is still in good condition, judging by
the electrolyte gravity and the time it will run the headlights
without dropping too far.


13+ years? Not bad. I just replaced my Tundra battery last year,
so
I got 9 on the original.


Did you do anything to maintain it?
I caught one cell on my truck battery dropping out a few years ago and
began charging it and checking the level more often. It seems to have
recovered.


No. It never seemed to use water, and after 4 years, I don't even
look at batteries, I just replace them (in vehicles.) ONE stranding
per lifetime is all you need to move to that route. I love canned
terminal protectant. I clean the terms, spray them down, and seldom
have to approach them again during the life of the battery.
I heart purple goo.


I wish LiFePO batteries were 10x cheaper now. I'd get a few KW of
those instead of LA. Tesla keeps making strong drops in pricing on
their battery tech. A couple 10kw modules would be nice, eh?


A friend is getting a quote from Solar City, which is connected to
Tesla. When the engineers come by I'm going to find out as much as I
can about the technical possibilities. Their site is useless.


It's a fact-filled site...if you're a clueless sheeple consumer.
Please let me know what you find out, although I'll never be able to
afford one, let alone two.


Segway stores large pallets of Lithium batteries at the factory. The
fire department's practice response for a large Class D fire next to a
river was awesome.
http://www.fire-extinguisher101.com/class-d-fires.html


I'll keep a pound or two of baking soda handy for my metal fires.


I needed to use a very reactive Lithium compound for an organic
synthesis and a helpful grad student came over to break off a chunk
from the rock-like mass in the can. As soon as he tapped the chisel it
burst into brilliant crimson flame and all we could do was pull down
the fume hood door and watch it all go up, then go request another
can.


Ouch! But pretty, huh?

--
Our main business is not to see what lies dimly at
a distance but to do what lies clearly at hand.
--Thomas Carlyle