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Author Topic: Grid Hopping  (Read 62726 times)
biff
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« Reply #15 on: July 13, 2015, 08:55:20 AM »

Hi Again Scruff,
              The 36cells are green topped Floride lead acids and are still sitting in the old forklift they came in over 7 years ago. I only take the pack up to 146volts twice a year and only for a couple of hours each time. At the height of the incoming power during the summer,the controllers only allow the voltage to creep to 140max but can hold that for a good 8 hours in summer.The excess goes into the tanks in 2 x 2kw dc immersions which do a great job, hence me getting roasted while building the brickwork around the new stove pipework last week.
  I got the acid from the suppliers, A friend,retired from rewindings,alternator,starter,electric motors and most things electrical gave me the number and told me to say xxxxxxx said xxxx xxxx Grin and a couple of days later, I had a pretty pallet sitting on the front street with a dozen 2.5 jars of No 8 acid which I was told goes directly into the cells and needs nothing else. Sure enough, I had a few batts which had sat for a good 10 years dry,(from new) and when topped up with this miracle restorer, sprang to life. The price of the acid was some 30cents a ltr cheaper than distilled water. Buying the distilled water was causing me a severe pangs of regret and self doubt and worst of all a certain inbalance in my stride because one hip became considerably lighter than the other, so I went back to the old system of collecting the juice of our winter dust free north westerlies.The last time I bought the stuff, it cost me 64 euros for 40 ltrs of the stuff and I swear that our 60 cells were moaning and asking for the rain water with slight taste of the Atlantic instead. The summer delivery is a different kettle of fish,or should i say,frogs,newts,bathing birdies and fox,cat,mink stopping for a pint. So winter collected rain is the order of the day. I store in in clear 5 ltr jars in which it sits for months in the dark and appears pure and clean as the day it was captured.
  As  little side story,,, I went to the local hardware shop to look for something that would clean the soot of the face of the brickwork, now I know that that is a job ,",impossibleeee". but I had to try.
 The guy in the shop, stood upright ,hands on hips and preached in a negative fashion about the contrary  values of soot ."There is nothing as soul destroying as soot on your fireplace" he confided and lowering his voice to get my attention ,he swung round and pulled a 5ltr plastic jar off the shelf. It had warning all over it. It could kill. " Holy mooly it was dangerous" I said "It must be good"
 " Look there" he said tapping the line that stated the contents.  " It has got hydraulic acid" He explained.   "But, But  only 12.5%" I argued
  "but the stuff is liquid gold and impossible to obtain on the open market" " The 100% version would burn its way through to OZZ man" he said, throwing his head back like victors do.
  " I have some stronger stuff already" I said.
 " No you don,t,,well you could,nt have, well you have no reason to have it,what would you be doing with that stuff"   he muttered retreating.
  "I put it in Batteries" I chirped.
  " Batteries come with it already in them" he chortled.
  " I had a few delivered dry and had to put the acid in them myself" I explained,
  " What ta xxx would ya be doing with dry batteries,,wait,,donm,t answer that and he turned round to another customer. He is still the most helpfull guy you could possibly find. The moral of the story is,
  " If ya wanna sell,, buum it up alright but don,t say what it in it" The chances are some clown might have it at home.
                                             Biff
  NB The acid did help clean the brickwork, not perfectly but lowered it to an acceptable level..
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jonesy
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« Reply #16 on: July 13, 2015, 10:19:50 PM »

Where do you get concentrated H2SO4
35% strong enough?  Any hardware store in France, along with acetone, hydrochloric, ammonia.  Can't get IPA easily.
Iirc 2/litre
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« Reply #17 on: July 14, 2015, 10:55:43 AM »

Ready for dilution for batteries.
UN1830-Sulphuric acid with more than 51 per cent acid. Delivery guy wanted to throw it off the lorry as he didn't have a tail lift and my forklift was broken help.


* acid.jpg (554.92 KB, 920x1632 - viewed 1832 times.)
« Last Edit: July 14, 2015, 10:58:22 AM by Tinbum » Logged

85no 58mm solar thermal tubes, 28.5Kw PV, 3 x Sunny Backup 5048, 3x Sunny Island 5048, 2795 Ah (135kWh) (c20) Rolls batteries 48v, Atmos wood gasification boiler, Brosley wood burner, 2000lt buffer tank and 250lt DHW
biff
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« Reply #18 on: July 14, 2015, 05:48:02 PM »

Ah Ha,, Tinbum,
               That stuff would shift the soot,,if not the bricks themselves.. whistlie
                                                             Biff
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« Reply #19 on: July 14, 2015, 06:21:34 PM »

If I recall its pretty well 100% acid. horror
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85no 58mm solar thermal tubes, 28.5Kw PV, 3 x Sunny Backup 5048, 3x Sunny Island 5048, 2795 Ah (135kWh) (c20) Rolls batteries 48v, Atmos wood gasification boiler, Brosley wood burner, 2000lt buffer tank and 250lt DHW
Scruff
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« Reply #20 on: July 14, 2015, 06:49:45 PM »

I'll put a barrel on the yee olde shopping liste. Thanks guys.
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« Reply #21 on: July 14, 2015, 07:11:34 PM »



One shot drain cleaner from b&q is 91% sulphuric.  Add acid to water to dilute, and I always wear safety glasses and gloves.  I used it for anodising a home made bike light some time back, worked well, bike now nicked though😩
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« Reply #22 on: July 14, 2015, 08:58:13 PM »

I got mine from here;

http://www.trinity-research.co.uk/index.php?cPath=21_96_23_106_35&osCsid=1qkakl6ju2820h84h33oi0vgn7
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85no 58mm solar thermal tubes, 28.5Kw PV, 3 x Sunny Backup 5048, 3x Sunny Island 5048, 2795 Ah (135kWh) (c20) Rolls batteries 48v, Atmos wood gasification boiler, Brosley wood burner, 2000lt buffer tank and 250lt DHW
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« Reply #23 on: July 20, 2015, 07:18:26 PM »

Has anyone forged their own TriStar remote temperature sensor?



Behold my 0.10 TriStar RTS.

 genuflect

Thermistor type NTC 10kΩ @ 25C Beta curve 4160K (Beta response can vary manufacturer to manufacturer)

Lab test results:


It's pretty good. It's 2C high of actual @ -15C, 1C high from -10C to 10C and fairly on the money up to 30C.
It's only listed as 10% accuracy. So I broke the aulde piggy bank, got 5 and picked the best. Worst case scenario it puts me -48mV of where I want to be across my expected range.  extrahappy
And to be honest I never checked the genuine RTS to see how accurate that is.

Any suggestions for a good thermally conductive electrically insulating potting compound to lash this into a lug terminal?

Took me two rounds to reverse engineer this.
First round I had two meters and the genuine TS RTS. The results were messy because I didn't factor response time and my clamp meter only goes to 7kΩ so I had to keep swapping the leads and ranges on the 87V.
It was enough to get me the wrong thermistor, right ballpark which I used for the round two results.



Round 2: I used the wrong thermistor to chart the results rather than breaking my van looms to get an RTS in the house. The TriStar was giving me a temperature reading via MSView and I could read the corresponding reading of resistance on the ohmmeter. However the ohmmeter drops a small voltage onto the circuit to measure resistance which in this case was changing the resistance and therefore temperature as read by the TS so that's what the relays are for. I just needed a DPDT switch to  swap between the TriStar and meter inputs both reading the same resistance with different references. Didn't have one in the spares clobber though so I made one from a switch, a SPST relay and a SPDT relay with the coils paralleled on an isolated supply.

The idea is to plot resistance versus temperature in 5C increments to narrow down the parameters, to compare to a component datasheet.
Which takes ages by the way because there's thousands of variants... faint

I reckon you could apply the same method to any RTS.  fingers crossed! ...if they're just thermistors and not an evil thermistor based potential divider.

The sub zero results are the most telling because they have a logarithmic response and <-5C is the steep end of the bell curve.
« Last Edit: July 20, 2015, 08:00:10 PM by Scruff » Logged
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« Reply #24 on: July 20, 2015, 07:50:12 PM »

Other recent events; I got myself a cheapo and accurate "zero centre" ammeter with a 200A shunt from eblag. It's putting the TS meter to shame. I calibrated it against the Fluke with the PCB mounted trimpot. So when the TS tells me it's floating @ 0.0A the ammeter tells me there's just under an amp. I hate dishonest meters  fume...I wonder if it's calibrated for piece of mind as in to stop people complaining that it never stops charging. It's a bit hit and miss in absorption too it's usually reading about 500mA low of actual. Othertimes it's spot on. Which leads me to suspect the Ah counter is inaccurate too.



Anyways true to form since I let the TS at the batteries it's put over 1kWh into them after all my other chargers signed off.  genuflect

I got an ebag voltmeter too but it's been returned to sender because it was 185mV out of spec and non adjustable.

Made a layout plan for the power station. Trying to mix voltages as little as possible and keep things modular. I'm gonna start panel making soon. Might start with the busbars...from what's on the market it makes less sense to buy them than make them.

« Last Edit: July 23, 2015, 08:50:40 PM by Scruff » Logged
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« Reply #25 on: August 07, 2015, 04:12:49 AM »

Shame having photons and nowhere to put them. I had a tinker with some strip lights I have in the junk bin. I have some fancy drivers and fancy controllers but decided against them because it was all too elaborate. Besides I don't really like the colour temperatures of these things.

This is a little proof of concept. I've decommissioned them since...I might reinstate them later but I'd rather some 2700K CRI 95 jobbies instead of the RGB ones. Besides these have loads of dead strips that need a splice.

Here's my home brew controller. A bank of three switches for each strip and a switch for every colour. Another switch would be useful as a Master. Having two strips is handy for hot wiring these because you can mix some colours to 50% eg: strip A 100% red and 100% green with strip B 100% red = amber.
I wired them direct to battery.
The heat sink is my "regulator". Its just a diode to stop the leds cooking with charging voltages with the 1.4V diode drop.



Oh and watch out these are commonly switched on the negative.

« Last Edit: August 07, 2015, 05:55:50 PM by Scruff » Logged
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« Reply #26 on: August 07, 2015, 04:28:24 AM »

I couldn't find any decent busbars for sensible money so I decided to make them.

Ingredients:

Hardware: M8s, M6s, spring washers, washers.
PVC U-channel
5 bus bar insulators,
Copper flat bar.
Perspex.
Rubber chair stops.



I wanted to tap the bolts but I drilled the holes too big before I noticed.  facepalm
Pretty low tech. endeavour, clean the flat bar, drill it out mount the hardware.

The U channel is a mite light duty, I may swap it for someat else, in the mean time I stacked it three layers high and riveted them together.
There's a slide notch cut in the perspex for servicing so the plate rotates rather than having to be demounted.  



Scruff's 300A busbars complete with shunt.


The trick to mounting these is to make sure they're a spanner's length apart.  Grin
« Last Edit: August 07, 2015, 11:56:59 AM by Scruff » Logged
biff
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« Reply #27 on: August 07, 2015, 10:06:50 AM »

That is one neat job Scruff,
                         I did similar with the flat copper pipe but not half as neat as that and yours is safe and by the book.
             In fact, You have shown me how to do it properly. Thank you. I have the bits and bobs so I will get cracking on a pair before long
                                                           Biff
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« Reply #28 on: August 07, 2015, 05:39:36 PM »

Just finished the infrastructure.

First up the rogue electron subjugation device.



It's in the next room. Best not have to venture into the fireball to get an extinguisher...seems like common sense but I'm constantly moving them a few meters from three phase distros only to find some H&S Jobsworth has resited them in their allocated place.  Roll Eyes


I've also built a shrine to the electrons.  genuflect



It's free standing with some extra storage so I don't have to riddle the wall with screw holes when I get my panels together. It also means it's easier transport to another site as a pre-wired board...erm...maybe.

It's all a bit untidy now but that's because I'm not inclined to cut up my conductor stock and run conduit in the wrong directions just to float charge. I'll loom it rightways and on correctly colour coded cables as and when I have things how I'd like.

That is one neat job Scruff,

Thanks Biff...at least it was until I mounted them... whistlie

                        I did similar with the flat copper pipe...


I thought about copper pipe but I'm not sure it's a great idea to work harden the main bus.
My original spec. was for brass nuts and bolts with copper washers but I had a budget reassessment with an ohmmeter.  Grin



Oh by the way, try to avoid using a red ammeter with a blue voltmeter or vice versa..they have this weird 3d goggles effect and it's really hard to focus on both at the same time...took me days to figure out why one was always blurry.
« Last Edit: August 07, 2015, 05:48:18 PM by Scruff » Logged
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« Reply #29 on: September 08, 2015, 12:30:24 AM »

Brand spankin' shiney new, RRP extrahappy
How could I resist!



I didn't even want a charger.  lovefirefox



Complete with Masterbus hub, battery temp sensor and Masterbus T-plug.

I was turned off the Switz-swoo inverter in the end because I couldn't find a cheapy  Grin their inverters cost more than their combis, and the XPC made some dreadful design decisions, it's 200 extra for the unit to program the charger, then you can't even program it you can only select options...there's no 58.8v charge setpoint  Undecided just 57.6V or a range of molten lead  Roll Eyes.

The Mass Sine is neat. Comprehensively programmable...must figure out how next...It'll start a 1350watt universal motor. Inrush on mains for said motor is 30A on the Mass Sine it's 10A< 6A...looks like soft starting. Runs a 95C washing machine load no bother, max. surge was 3500W  extrahappy
I woulda prefered a low frequency job for surge capability and this is better suited a boat than a house when it comes to certain features but it saves me a loada switchgear and possibly a charger. I'm testing it against the TriStar in the morning for charge-ability, my money's on Morningstar.

Had a look at the efficiencies, these aren't continuous load states so maybe derate for heat but I found the inverter 96% efficient at 60% load and the charger 86% at full load, best results I've seen yet.
Idle is ~7W...better than my 600W MSW. (I need to monitor it over time for more accurate results)

I've two concerns; One is the earth neutralising link is a relay (it's a boat thing I think). I'm not sure I can hard wire it as the output is sometimes a mains throughput. How would I go about triggering an alarm or warning light if the switch contacts fail open in inverter mode? Or setup a continuity LED that doesn't trip the RCD?

Can I AC couple this without frequency shifting? GTI into genset input, inverter in gen. support mode and dump loads on the battery?


Nudey photos for the lectronics fanciers;

Conformal coated, quality caps(mostly), Nichicon and Rubycon, forced air blows down. Solid battery clamps. Shiney!
















« Last Edit: September 08, 2015, 12:45:51 AM by Scruff » Logged
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