Living offgrid with small solar system(s)

[Muhendis]

For those interested in LifePo cells, make sure you do your research, as you're going to have to give them a nice temperature controlled environment in order to achieve manufacturer claims.

At low temperatures (freezing) LiFePO4's can be discharged but the capacity will be lower. They cannot be charged at freezing. At elevated temperatures the capacity increases offering as much as10% more capacity due to higher lithium ionic conductivity. Taking them above 60 deg. C can be detrimental to the battery. Above 70 deg. C there are internal chemicals which will begin to evaporate causing gas buildup and internal pressure. Above 80 deg C there are internal plastics which will begin to deteriorate.

[George Harmony]

Laboratory results indicate that you could expect to see 2,000 to 5,000 cycles out of a well cared for LiFePO4 battery bank, which means that a lithium ion battery bank has the potential to likely outlast your RV!

In contrast, even the best deep cycle lead acid batteries are typically only good for 500-1000 cycles.

As already explained by @muhendis. So, how about the price ?

Supplier quote me a price of 50ah sla here where i am for about 130usd. The above 40ah lifepo is 100usd more expensive. What is wisdom if you intend to buy a battery which daily in the evening can supply about 300wh ???

Lifepo, interesting or not??

Edited April 18, 2016 by George Harmony

[KonaRain]

Interesting, yes...

Thanks so far..

We may have a good one here,

Aloha

[KonaRain]

Interesting @crossy.

I find this one for 1300usd. What i dont undrstand r the specs. Does this battery have a build in charge controller???

$1,300 for measly 108 amp hours?

what am i missing?

10 KW is what I meant.

A reconfigured block of em weighed 140 pounds..

Tessa's is 3,000$.

I'M sure we're on right track.

A 200 mile electric car will powers a house with 4 kw.

For as long as it takes to go 200 miles..

Sounds like a lousy inve$tment..

[Muhendis]

An additional comment on LiFePO4's over lead acid.

To maximize cycle life of a lead acid battery you would limit the discharge to 30% of the battery capacity so in the case of a 200Ahr battery you would only use 60Ahr the remaining 140Ahr is not used.

A 200Ahr LiFePO4 battery with a discharge limit of 90% would yield 180Ahr the remaining 20Ahr is not used.

So. If your lead acid battery giving 60Ahr of useable capacity is enough for your application then a LiFePO4 battery with a capacity of 66.6Ahr will do the same job. In other words you don't need to buy a LiFePO4 battery of the same amp hour rating as the lead acid battery to get the same performance.

A further advantage of LiFePO4's is that they must not be trickle/float charged whereas lead acid batteries must (internal resistance causing self discharge) and so take more power from the charging system.

[Naam]

March 18, 2016

Even at Tesla’s low wholesale price, a 500-cycle battery just doesn’t pencil out against the alternatives, especially once the inverter and other system costs are included. State-of-the-art backup generators from companies like Generac and Cummins sell for $5,000 or less. These companies also offer financing, which removes any advantage Tesla might claim with that tactic, as GTM’s Jeff St. John pointed out last spring.

“Even some of the deep cycling lead acid batteries offer 1,000 cycles and cost less than half of the $3,500 price tag for Tesla Powerwall,” said Ravi Manghani, senior energy storage analyst at GTM Research. “For pure backup applications only providing 500 cycles, lead acid batteries or gensets are way more economical.”

http://www.greentechmedia.com/articles/read/Tesla-Discontinues-10kWh-Powerwall-Home-Battery

[Muhendis]

March 18, 2016

Even at Tesla’s low wholesale price, a 500-cycle battery just doesn’t pencil out against the alternatives, especially once the inverter and other system costs are included. State-of-the-art backup generators from companies like Generac and Cummins sell for $5,000 or less. These companies also offer financing, which removes any advantage Tesla might claim with that tactic, as GTM’s Jeff St. John pointed out last spring.

“Even some of the deep cycling lead acid batteries offer 1,000 cycles and cost less than half of the $3,500 price tag for Tesla Powerwall,” said Ravi Manghani, senior energy storage analyst at GTM Research. “For pure backup applications only providing 500 cycles, lead acid batteries or gensets are way more economical.”

http://www.greentechmedia.com/articles/read/Tesla-Discontinues-10kWh-Powerwall-Home-Battery

Thanks N@@m. I haven't had such a good laugh for a long time. What is a 500 cycle battery? The only battery chemistry I know which matches that is lead acid. Inverter and system costs are totally irrelevant since they are needed whatever chemistry battery you use. What sort of "state of the art" backup generator is this man talking about that costs $5,000? I have a 3kW unit which cost around $300 (9500 Bht)

http://inhabitat.com/teslas-powerwall-battery-is-a-stylish-but-expensive-way-to-ditch-the-grid/ This link is all about a 10KWhr unit for $3500 which is the sort of power American homes need? If that price (10.85 Bht per KWhr) is for LiFePO4 batteries then it is getting into the affordability arena for me. Watch this space..............

[Naam]

March 18, 2016

Even at Tesla’s low wholesale price, a 500-cycle battery just doesn’t pencil out against the alternatives, especially once the inverter and other system costs are included. State-of-the-art backup generators from companies like Generac and Cummins sell for $5,000 or less. These companies also offer financing, which removes any advantage Tesla might claim with that tactic, as GTM’s Jeff St. John pointed out last spring.

“Even some of the deep cycling lead acid batteries offer 1,000 cycles and cost less than half of the $3,500 price tag for Tesla Powerwall,” said Ravi Manghani, senior energy storage analyst at GTM Research. “For pure backup applications only providing 500 cycles, lead acid batteries or gensets are way more economical.”

http://www.greentechmedia.com/articles/read/Tesla-Discontinues-10kWh-Powerwall-Home-Battery

Thanks N@@m. I haven't had such a good laugh for a long time. What is a 500 cycle battery? The only battery chemistry I know which matches that is lead acid. Inverter and system costs are totally irrelevant since they are needed whatever chemistry battery you use. What sort of "state of the art" backup generator is this man talking about that costs $5,000? I have a 3kW unit which cost around $300 (9500 Bht)

http://inhabitat.com/teslas-powerwall-battery-is-a-stylish-but-expensive-way-to-ditch-the-grid/ This link is all about a 10KWhr unit for $3500 which is the sort of power American homes need? If that price (10.85 Bht per KWhr) is for LiFePO4 batteries then it is getting into the affordability arena for me. Watch this space..............

this article pertains to the average U.S. consumer Muhendis who usually has an central airconditioned home (4 tons / 48,000 btu/h / 40-50 starting amps) and for whom a $300 toy is as useless as are the tits of a nun.

also the Tesla10kWh (which is not built anymore but replaced by a 7kWh) is as useless as a toy genset.

[George Harmony]

How about this:

A US town has rejected a proposal for a solar farm following public concerns.

Members of the public in Woodland, North Carolina, expressed their fear and mistrust at the proposal to allow Strata Solar Company to build a solar farm off Highway 258.

During the Woodland Town Council meeting, one local man, Bobby Mann, said solar farms would suck up all the energy from the sun and businesses would not go to Woodland,

http://www.independent.co.uk/news/world/americas/us-town-rejects-solar-panels-amid-fears-they-suck-up-all-the-energy-from-the-sun-a6771526.html

[George Harmony]

Ive just been reading this:

At the ongoing Consumer Electronics Show (CES) in Las Vegas, eZelleron, an innovative start-up based in Dresden, unveiled kraftwerk, a portable water-powered charger that enables you to generate your own energy enough to charge your iPhone, tablet, or even your GoPro camera for weeks using a small, handy device. eZelleron has been developing low-emission energy sources for mobile power supplies since 2008.

Their Kickstarter campaign wowed many at the CES as it raised over $200,000 in just three days! The German company building the kraftwerk water cell phone charger is an impressive brain trust focused on fuel cell and other related material sciences. As a result, the kraftwerk charger appears about as effective as can be for portable charging.

http://infoboxdaily.com/who-needs-a-powerbank-when-you-have-a-water-powered-portable-charger/

Is it not possible to produce bigger capacity water powered batteries??

[Naam]

Ive just been reading this:

Is it not possible to produce bigger capacity water powered batteries??

this is neither a battery nor powered by water. it is supposed to be a fuel cell and looking at the price of $99 it is meant for naïve people who use pliers to pull up their underpants

here's what you get from ebay at a fraction of the price ($24):

Universal 200000mAh Solar Power Bank Dual Backup

http://www.ebay.de/itm/Universal-200000mAh-Solar-Power-Bank-Dual-Backup-Ladekabel-Akku-Schwarz-UJM-/252331279587?hash=item3ac01dc4e3:g:uIwAAOSw4UtWTAI6

[Gary A]

I looked at the Tesla battery specs and besides being more than twice as expensive, the voltages for charging and the inverter are not suitable using conventional components. Since my one small system is in the house, I opted for AGM sealed batteries. No fumes or maintenance. Four batteries at about 5,300 baht each for 65 AH was expensive but that set is now three years old. I should add that my system is mainly manual as far as depth of discharge. I VERY seldom go below 50 percent depth of discharge. My MPPT charge controller will shut down the system at low voltage but it is not adjustable for depth of discharge, I simply keep an eye on my volt meter.

Hopefully in the near future there will be a technology breakthrough and batteries will be cheaper and more efficient. Unfortunately that day is not here yet. Tesla is the closest but they are not there yet. My AGM batteries have been through near a thousand cycles already.

[IMHO]

Here's one for @George

Maybe you could scale this up for your pool

[IMHO]

Here's another one just taking advantage of the difference in photocatalysis of black and white surfaces:

[Naam]

my experience: lead acid 12v, 2x120ah each 3,300 Baht in series 24v powering two waterpumps lasted 3½ years in ambient environment. same bank in airconditioned environment powering big screen TVs, PCs, lights and ceiling fans lasted 4 years and 9 months.

fumes inhouse banks a breeze exhausted with 8" 12v PC fans (200 Baht). monthly water check mandatory as inverter integrated chargers trickle charge even when no demand on banks.

deep cycle batteries costing a multiple? no thank you.

pure sine wave inverters? my family name is neither al-Saud nor H@rmony. in China produced inverters imported brought from India INR 7,200 = 3,800 Baht a piece.

[Naam]

one more for @George's pool:

[George Harmony]

So, pls inform me @naam.

How many hours per day do you run your swimming pool pump and how many watt is it using after startup.

[Muhendis]

Hmmmm. This should be g@@d.

[Naam]

So, pls inform me @naam.

How many hours per day do you run your swimming pool pump and how many watt is it using after startup.

the running hours of the pump depend on the heating demand of my pool. if there is no demand daily 2½ hours of filter time are sufficient to mainly sanitise the water by a very low dose of chemicals alternatively CL and H²O² as well as an 80w UV-bulb.

runtime can go up to 6 and more hours during a prolonged cool period which i only experienced once in Thailand (dec2008 - jan2009).

reason for the rather low filter time: enclosed pool area integrated in a U-shaped home; 5.8 running amps after startup.

[KonaRain]

Thanks for your reply @muhendis.

You wrote:

If the battery is FLA (That's the one with screw caps to allow topping up of the acid with distilled water and to allow readings of the SG to be made) then you can keep an eye on the acid level and apply a desulfation cycle ever so often.

If i manage to store the FLA battery outside there is no healty risk. If i understood well a fla battery can have a longer life if you regularely service the battery.

If i plan to buy later the following only for using the electric wok:

1x100wp panel, gives me on a normal day min. 450watt

1x125ah fla deep cycle battery

1xinverter 2000watt

So after using the wok 450watt the battery will be full again.

Is it possible then than the battery last at least 5 years??

Look how handy such a wok is. Cooking where ever you want, even on the dining table or at your terrace.

I live in an offgrid subdivision.. My neighbors run their generator along with solar panels when running an applience like the elec. wok.

jus' saying.

Aloha

[KonaRain]

my experience: lead acid 12v, 2x120ah each 3,300 Baht in series 24v powering two waterpumps lasted 3½ years in ambient environment. same bank in airconditioned environment powering big screen TVs, PCs, lights and ceiling fans lasted 4 years and 9 months.

fumes inhouse banks a breeze exhausted with 8" 12v PC fans (200 Baht). monthly water check mandatory as inverter integrated chargers trickle charge even when no demand on banks.

deep cycle batteries costing a multiple? no thank you.

pure sine wave inverters? my family name is neither al-Saud nor H@rmony. in China produced inverters imported brought from India INR 7,200 = 3,800 Baht a piece.

I found a lot of pure sine wave inverters on da web...using google

[Naam]

I found a lot of pure sine wave inverters on da web...using google

i can find a zillion pure sine inverters too but i am not willing to pay for something i don't need even though learned people are telling me horrified " no pure sine wave inverters? all your electronics will conk off!"

[George Harmony]

As expected most germans like @naam arranged all well and surprisingly also your english is like an aussie hahahahha....unlike other germans i know its thump up @naam.

Ok...according to the specs of this dc toy it can pump 13000 ltr in one hour. With 200wp panel it can run easily during peak hours with a (dummy) battery. Lets say i can pump 8000ltr per hour x 4 then i think i can plan for my small pool attached to my planned gazebo above the pond

Edited April 20, 2016 by George Harmony

[Muhendis]

As expected most germans like @naam arranged all well and surprisingly also your english is like an aussie hahahahha....unlike other germans i know its thump up @naam.

Ok...according to the specs of this dc toy it can pump 13000 ltr in one hour. With 200wp panel it can run easily during peak hours with a (dummy) battery. Lets say i can pump 8000ltr per hour x 4 then i think i can plan for my small pool attached to my planned gazebo above the pond

That's a good pump you found there George and please stop insulting the English language

[Gary A]

I found a lot of pure sine wave inverters on da web...using google

i can find a zillion pure sine inverters too but i am not willing to pay for something i don't need even though learned people are telling me horrified " no pure sine wave inverters? all your electronics will conk off!"

I'm certainly no electronics expert but I did do my research. I have three pure sine wave inverters. They were not that much more expensive. They all came from China and two of them are now three years old with no problems. One is a spare because I had no idea how long they would last. My research told me that my computer would not like modified sine wave and the refrigerator compressor motor would run hotter and would not last as long. I spent the extra money. Am I wrong? Also for in the house I bought four 65 AH AGM sealed batteries. My other small system has two 125 AH flooded batteries. All are deep cycle. Both sets of batteries have been running for three years. Time will tell which set lasts longer.The flooded 125 AH batteries cost about half of what the AGM batteries cost for the same power.

[KonaRain]

Good going..thanks for sharing. .my off grid neighbor's have a 12V refrigerator, and some have propane cooling! They still run generators during the day. Aloha to You

[Muhendis]

I found a lot of pure sine wave inverters on da web...using google

i can find a zillion pure sine inverters too but i am not willing to pay for something i don't need even though learned people are telling me horrified " no pure sine wave inverters? all your electronics will conk off!"

I'm certainly no electronics expert but I did do my research. I have three pure sine wave inverters. They were not that much more expensive. They all came from China and two of them are now three years old with no problems. One is a spare because I had no idea how long they would last. My research told me that my computer would not like modified sine wave and the refrigerator compressor motor would run hotter and would not last as long. I spent the extra money. Am I wrong? Also for in the house I bought four 65 AH AGM sealed batteries. My other small system has two 125 AH flooded batteries. All are deep cycle. Both sets of batteries have been running for three years. Time will tell which set lasts longer.The flooded 125 AH batteries cost about half of what the AGM batteries cost for the same power.

Well Gary A you certainly did the right thing getting a spare inverter. China does not have a reputation for quality control so you have done well with them lasting for three years. You were absolutely right about needing a pure sine wave generator for your fridge motor. I won't go into to many details but suffice it to say that the motor is designed for sine wave power. Switching it on and off with positive and negative square wave pulses which is what a modified sine wave is, will not take advantage of the impedance characteristics of the motor but will instead drive much more current through the coils dc resistance hence they get hot.

The results of the competition between your flooded and AGM batteries is not going to be of any use unless both sets are getting the same charge/discharge cycle. AGM's are very useful on boats because their construction ensures they are spill proof. After all, when rolling about in a force 6 the last thing you want to worry about is battery acid splashing about inside your boat. That is not normally a problem with a stationary battery. FLA's (flooded lead acid) are fine for stationary setup's and as you have said they are the least expensive. They do have problems which may restrict their choice for some. They need, as Naam George have said, to be in a well ventilated location. They need regular topping up with distilled water and they need occasional desulfation (referred to by some as equalisation). Another downside not often considered is that if you were working away from home for six months, would your batteries still be in a fit state when you got back or would your wife ignore them because their maintenance is a mans job. For the home, a better choice would be VRLA (valve regulated lead acid) or sealed maintenance free batteries. Like the AGM these are both fine to use indoors. Also like the AGM however they are more fussy than FLA's about how you charge them. They will not tolerate being overcharged.

Edited April 21, 2016 by Muhendis

[Naam]

As expected most germans like @naam arranged all well and surprisingly also your english is like an aussie hahahahha....unlike other germans i know its thump up @naam.

Ok...according to the specs of this dc toy it can pump 13000 ltr in one hour. With 200wp panel it can run easily during peak hours with a (dummy) battery. Lets say i can pump 8000ltr per hour x 4 then i think i can plan for my small pool attached to my planned gazebo above the pond

a miracle pump! 600% more effective than my pump, i envy you! not for the pump but for your faith in believing marketing BS

[Naam]

Well Gary A you certainly did the right thing getting a spare inverter. China does not have a reputation for quality control so you have done well with them lasting for three years.

two of my Chineses inverters lasted 9½ years and still work, one had a minor problem and was repaired for 700 Baht. but having a spare is a good idea, in my case having five spares is a good idea too.

China bashing isn't one of my favourite pastimes as i was always quite happy with the price/performance ratio. mileages may differ of course.

[George Harmony]

This one ive found while googling in googleNL.

What does it mean? 3.4m3 per hour??? Capacity of pumping 3400ltr per hour??

So, if i can run this during peakhours it will be only only 12000-13000ltr. It will then be a very small pool or an undeep pool.