Muhendis

Or a simple inverter + ESS +ATS and forget about export. PEA then becomes your backup if ever needed.

Yes. As mentioned in the link, that lack of air is a problem but there is enough to give lift with that massive wing area. I would recommend you read the full article which I found quite fascinating. At an altitude of 65,000 feet there is virtually no turbulence and guaranteed sunshine for the solar panels which will give maximum power to the motors.

I think you're missing the all important word "informally" which I take to mean being paid cash in hand and undeclared income. Formal working is fine regardless of age because the government gets their tax.

In God we trust All others pay cash

Does it really matter? If things work when you switch 'em on You have achieved success. Well done.

Brilliant. Best way to do it. An additional benefit is when there is a dull night on TV you can spend a few hours admiring your achievement.

This is good and probably exactly what you want, but I was asking about your batteries. Your link is for solar panels.

That looks suspiciously like an MPPT graph to me. Do you have another one at 25ºC for reference? Also do you have a graph of life expectancy at varying temperatures and depths of discharge? Those are the things I would be looking for when determining the effects of temperature on batteries of any chemistry.

Generally, the operating temperature range of lithium-ion batteries is 15°C~35°C. If the temperature is too high or too low, the battery will not work. A bit of research by an American team has improved things a bit by widening the temperature range -40º to +50º and increasing power. This is achieved by modifying the electrolyte. See here; https://m.energytrend.com/news/20220719-29274.html But, like all emerging technology, there may be downsides which will prevent it from becoming common-or-garden batteries however if you want to be a high flier and are BAE with buckets full of money, then no problem.

Yeah. No problems with lithium and thermal runaway there methinks

I am thinking about that 65,000 ft altitude. I wonder what those lithium batteries think of those Temperatures? Must be minus a lot.

Whilst browsing for things interesting like you do, I came across this bit about uses for solar panels. A new (ish) airplane called the Phasa-35 has taken to the skies. This one is a bit special because it is an electric, unmanned plane which can fly to about 65,000 feet. It weighs in at only 150kg and has a whopping top speed of ........ about 55 mph Payload weight is 15kg and flight duration is indefinite. Good for carrying spy cameras and internet repeaters etc. The downside is getting it up to cruising altitude. It is very delicate and with a wingspan of 35 metres, cannot withstand much buffeting. Batteries are Lithium. Here is the web site for detailed information. https://www.prismaticltd.co.uk/?page_id=289

Yes. Quite. However it would be better if Strettha were to do this quietly without making a big issue of it.

Each battery is a nominal 12v so from Ohms law 250Ah x 12v = 3kWh and I have 12 of them giving me 36kWh at 48v. Bur the important point in this thread is there is no chemical fire risk.

Lithium based battery chemistry is generally pretty safe these days due mainly to the addition of iron into the chemical mix. When a LiFePO4 battery is charged it will get warm due to the flow of ions from one electrode to the other, likewise when it is being used but the ions flow in the opposite direction. The heat generated can be controlled by limiting this flow to a safe level hence limiting the temperature rise. This is controlled by the BMS (Battery Management System) which is absolutely essential for lithium ion batteries. In a lithium battery the temperature of the start of combustion is about 250ºC. By adding iron into the mix that temperature is raised by about 100º to 350ºC. By charging the battery too fast or by overcharging these temperatures are likely to be reached. Another cause of too much current flow is something called dendrite growth. This is crystalline growth of the chemicals on the electrodes which can cause shorting between electrodes. By using the correct charger and BMS, problems of overheating are reduced. I use batteries for my solar energy storage but not lithium. Instead I use lead carbon which perform as well as LiFePO4's but without the price tag and with no fire danger. My choice of battery is not suitable for EV's because each 250Ah battery weighs 77kg

Yeah. He totally missed the point.

No mention of acrylic crowns. Mine will outlast me which is all I require. Gold crown? Why? Total waste of money unless you want your teeth worth more than the rest of you.

This bothers me a bit because according to immigration I'm an Alien

They certainly do. Safety-Cut, considered by many to be the Rolls Royce of protective devices and fitted to my CU by the original builder electrician, tripped but failed to cut the power. This I discovered some time after when testing. I replaced it with a less expensive RCBO and all was well again. On stripping the Safety-Cut down I found the trip coil jammed solid due to evidential overheating. Why did the Safety-Cut trip? Dunno but probably a transient fault. All's well now and tests continue on a monthly basis.

Yeah. I'll drink to that. Leo? Ok I'l put my coat on........

Well actually he lost his rights to anonymity the moment he became a public figure.

Builders in Thailand often locate the earth rod under the house where you can't access it. To verify it's existence, simply stick a bit of rebar into the ground close to the house, disconnect the house from utility supply and with a cheap multimeter set to read Ohms, measure the resistance between CU earth and rebar its should be no more than a few ohms.

An RCBO looks at the difference between currents flowing in the live and neutral wires. Depending on the setting of the sensitivity of this device the RCBO will trip if a current of 30milliamps to 10 milliamps is flowing more in one wire than the other. This minute current can flow through a body and cause the RCBO to trip thus disconnecting power before harm is done. Earth is not needed for this. The person who contacts the faulty equipment is quite likely grounded enough.

In my opinion the government should mandate the certification of electrical contractors and make it illegal to do electrical work without using a qualified and certified contractor. Certificates are required for tree fellers so why not for other trades too?

Today a lady in our village died. She was in her late seventies but still very fit and active. Cause of death was electrocution. She was in her outside kitchen in which has an earth/soil floor damp from the recent rains. Using a plastic electric jug kettle to heat some water, she was in the habit of putting her fingers into the water to see if it was warm enough. Today that stupidity cost her life. There was a fault in the electric element that made the water live. Current passed from her fingers and through her bare feet to ground. There was undoubtedly no earth at the power outlet. As with nearly all village houses, there is no ELCB. A sad and totally avoidable incident which could so easily have been avoided with a little more knowledge of how a house should be wired.