WT Hell is 48 volts all about

[Vik351]

Vik

If you already have the appliances, stick with 12 volts.

I originally started the fit out planning on 12volts but switched to 24.

The batteries and solar is set up for 24.

heater, lights, inverter and most other things are 24.

The water pump and gas cook top and gas water heater electrics is 12. (using a lillte converter for both) They are 12 becuase I had collected them before deciding to change to 24.

Yea jon_d, sorta sounds that way, reading more stuff and 1/2 the time I find they use 12 volt solar panels hooked up to get 24 anyway...

The less complicated it is is how I would like it... Will head up to Terry with the humpy on wheels one arvo(Whats his favorite tipple...???) let him have a look and go with that me thinks...

The last thing I want is to burn the thing down to the ground, I fiddle around with too much now,so there is no way I'm gunna muck around with stuff I know bugger all about

I will learn how to keep it ship shape etc, but thats it...!!!

All in all it looks like if you start with say an empty Bus, take the seats out and plan which way ya go from there, changin mid ships like Busman found out can be costly and dangerous to a novice like me...

So to date,lookin at decent solar panels, as many as I can fit, properly with air gaps,fall etc, decent controllers and Lithium battery set up.

http://img.photobucket.com/albums/v639/ ... lqcxcm.jpg

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[Busman]

Take a bottle of Durif or three, that'll get his attention !

[bob r]

Maybe some honey bourbon hmm ......maybe not won't get anything done.

Bob

[Vik351]

Take a bottle of Durif or three, that'll get his attention !

http://www.google.com.au/shopping/produ ... gKj4fD_BwE

Cases at that price...!!!

vik...

[Busman]

Not much good if you can only use it to wash the cat though, I would not be game to front up there with a $4 bottle of the stuff !

[homeless]

Plenty of Honey Bourbon because that's what Marg and I drink.
He drinks fifty lashes and that is what we use to get him going LOL.
I will be working on the boat for a while as progress is very slow now I cant see that well.
Ass long as it is drinkable some one will get it down.
Regards
Brian

[Lance]

Take a bottle of Durif or three, that'll get his attention !

http://www.google.com.au/shopping/produ ... gKj4fD_BwE

Cases at that price...!!!

vik...

Vik.....maaatteeee.........not a bad drop that one, good texture and flavoursome with a lingering smokey aroma.

Yep not bad that one, just like skwoshed grapes............but out around the fire, very pleasant

2017-08-19 18.50.24.jpg

Yep, not a bad drop that one

2017-08-19 18.49.59.jpg

But we digress, that fire is way over 48v, someone best explain just what 48v is and how it is related to the output of a firedrum or maybe even it's effective use in an an RV... ....48v, not the firedrum

[T1 Terry]

As has been said already, the old thinking of 34v or 48v being better was related to lead acid batteries. the reason was mostly the rate you could pull the power out of the battery before voltage drop became as serious issue and Peukert factor meant far less available capacity at a high current draw.
Don't let the eyes roll back just yet, I'll try to explain what all that meant.
An average 100Ah 12v AGM has a C20 rating, this means the advertised capacity (100Ah) divided by 20 hrs, in the case of a 100Ah battery that equals 5 amps. 50% available means 50amps @ 5 amps will give you 10hrs of energy supply. Then Mr Peukert through a spanner in the works with a formula to explain why 5 amps for 10hrs didn't mean you would get 50 amps for 1 hr. The formula is a bit like bistro maths, that thing women do when trying to split the restaurant bill All you really need to know is a lead acid battery (flooded cell, AGM, Gel, lead crystal) will only supply the 50% capacity at 5 amps per 100Ah capacity.
The next bit needs a bit of electrical understanding to do with amps, volts, watts and how it all fits together.
5 amps @ 12v =60w, amps x volts equals watts ad watts is the actual working capacity of energy and electricity is one form of energy. With this bit of info and the bit about 5 amps per 100Ah, if the battery voltage is doubled to 24v and the same 100Ah the available energy while still getting the full stored capacity doubles, 5 amps x 24v = 120w, at 48v the same occurs, now 240w is available but still only 5 amps load... I know it sounds a whole lot of Irish computer logic but that was the whole issue with using lead acid batteries for house battery use.
Then lithium technology entered the scene and made all that part of the 19th century technology where it started and remained. Lithium does not suffer a Peukert factor at the rate we use them for house power, 50 amps per 100Ah and up to 300 amps per 100Ah capacity before it really has enough of an effect to become a problem. Now 600w can easily be used from the 100Ah @ 12v battery for a whole hr before it would be considered discharged. That's right, the full 100Ah is available without damage if you really need it, but logic says it's always best to have a bit in reserve just in case the battery didn't have the full 100% capacity when the load started so the usual rule of thumb is to calculate on a max of 80% being used out of the battery before an alarm tells you to settle down a bit Our system will shut down the battery link at 50% capacity I think he meant 5%?remaining just to protect it and leave a little bit spare for an emergency..... that 5% is still plenty to start a big diesel engine for example so even though it is a 12v battery pack at a state of charge most would think was flat as a tack, it still has quite a bit of punch left.

No idea if that helped or really muddied the water but hopefully it helps to relieve any anxiety when a 12v lithium system is suggested yet some say it needs to be a higher voltage to run heavy loads..... the difference between lithium thinking and lead acid battery thinking when it comes to deep cycle house battery use, there are lead acid batteries that can supply the high loads but they can not supply the capacity to sustain those high loads for long periods where lithium batteries can.

T1 Terry

Thanks Bruce, it was meant to read 5% not 50%

[Vik351]

Thanks Terry...

"No idea if that helped or really muddied the water but hopefully it helps to relieve any anxiety when a 12v lithium system is suggested yet some say it needs to be a higher voltage to run heavy loads..... the difference between lithium thinking and lead acid battery thinking when it comes to deep cycle house battery use, there are lead acid batteries that can supply the high loads but they can not supply the capacity to sustain those high loads for long periods where lithium batteries can."

Thats the bit I get... so the MH garage sale of all my 12 volt stuff is off before it even got off the ground...!!!

Ahhh, to be able to sleep tonight without the 48 volt nightmares...!!!

vik...

[native pepper]

Vick, to give you an example of what Terry has posted. When we first went off grid back in 1976, getting the power to our land would mean wires and poles of 6 klms and that was out of the question. So we started off with old car batteries running on a big motor mower engine, driving a generator off a ford tractor, we could only run car interior lights and a car radio then.

We got our first solar panels a few years later along with some ex telstra 1000amp x 2v batteries, the cost of the panels was so high we could only afford a 10w and 40w. Which in reality provided virtually nothing and so relied upon 2 alternators running on a single cylinder diesel, but could still only run a 12v B/w tv, lights and 3 way small fridge.

It was the same with AGM and gel batteries, even though we had by them accumulated over 1000w of solar. Then one day my mate arrived with this box with what looked like little batteries in it, along with another box which had switches and wires coming out if it and told me to connect that to my house and tell him how it worked. At the time he was on grid and we off grid and struggling. So he was using us as the guinea pigs for his experiments with lifpo4 cells, previously he'd been playing around with various lithium chemistries and after a world trip, he came back with lifepo4 cells.

Even though this little pack was 120ah, it made our 2000ah agm batteries look like they had never worked. We bought a fridge, new colour tv and primitive 12v led lights. When I moved back to my home state of Tas 10 years ago, my mate provided a 700ah pack and 2kw of solar through his building business. Our new home was on the grid and thought deeply about staying on the grid because of the convenience, but he convinced me to disconnect and go full solar. So we took what he offered and went for it, must admit the thought of having to pay power bills after decades with none, was the catalyst. Since then he kept updating our system and advised on what we should change to suit the new stuff. Early controllers were combinations of relays, BMS and manual cutoff switches, which required watching.

Three years ago he arrived with a controller he built, which was dedicated to lifepo4 and nothing else. Then a few months later he arrived with what he called a cell equaliser and from there, have never touched the system, it just works.

Even though we now only have 700ah of lifepo4 and 4.2kw solar, compared to 2000ah of agm. We run inverter fridges, freezers, big led tv, led lights, inverter A/C, washing machines, vacum cleaners, induction cooking and everything else you use in a normal house. When my grand/great grand kids are here, they test our systems out as the TV goes constantly as does 3 computers and phones getting charged, lights are left on and yet the 700ah of lifepo4 just sits in a cupboard in my lounge and never gets below 13v.

The really dramatic thing with them in my opinion, is how fast they take charge. Used to take days of full sun to get the 200ah agm to full, if you are lucky. Now, can get up in the morning and the cells will be sitting on 13v, within a a couple of hours, they are on 13.8v. If it is a sunny day, at sunset they are still in 13.8v, even if there is just a couple of hours of sun, the pack is normally full and we use everything on sunny days. Do have a lister gennie backup, which runs the big stuff in my workshop and that's only used occasionally as my 120ah lifepo4 portable pack, runs the workshop on a variety of different wattage solar panels. Use the gennie for welding etc.

Same with the bus, used agm then gel and never had enough power for much beyond tv, 60lt 12v fridge radio and charging phones. Now have 480ah lifepo4 and 1kw solar and run everything you can think of, just like being home and can go many days without much sun.