offgrid power

[GW8IZR]

nice slow plodders, and water cooled

before father in law died he bought one which he sort of planned to show or at least just play with it, he gave it to someone to either fix something on it or show it to someone else and we have never seen it since, not entirely sure what the story was but its gone now anyway.

 

[the snooper]

before father in law died he bought one which he sort of planned to show or at least just play with it, he gave it to someone to either fix something on it or show it to someone else and we have never seen it since, not entirely sure what the story was but its gone now anyway.

I wouldn't have let that rest

 

[GW8IZR]

I wouldn't have let that rest

more important things in life sometimes.. but yep a shame anyway.

Thing is, ignoring efficiency and practicality an old Lister genset would be interesting in itself and run on chip fat if needed.

Like my merry tiller.. by the time its running and carried to the veg plot I could have dug it over with a spade but messing with petrol toys is part of the fun.

 

[dannyp]

the main problem here is i'm trying to help a freind of meany years, out of a hole who has had a fair run of reallys **** luck. i can throw some of my time at the problem, i can throw whatever materials i have here at it, and parts engines , alternators all thats sort of stuff. money well if needs must but there isn't much spare here

when it comes to modifying things i can hold my own, once i know what i need to acheve it will be done and it will work. thats what i do most days as part of my day job. what i'm trying to avoid doing is recovering ideas that have been tryed tested and found useless.

if i can make an AC1 charge 24v AGM batterys with an 80A 24v alternator thats brilliant because i have all of the bits. i know it may not be the IDEAL soultion but if a WORKING SOLUTION i can acheve with what i have without throwing loads of cash at it, it's a solution that'll be inplimented rather than candels

 

[dannyp]

anyway from what i'm reading atm there is no need for a MPPT solar charger, 24v alt startight to 24v battery, tho a pwm solar jobbie may be usefull for regulating the charge current if the voltage drop isn't to large.

if this is viable i'll get the alternator mounted up to a engine to test the idea, i have a 13hp lincon petrol enigne that i chould knock up a chassi plate a bit quick and throw som ebelts between them to test the idea

 

[GW8IZR]

if i can make an AC1 charge 24v AGM batterys with an 80A 24v alternator thats brilliant because i have all of the bits. i know it may not be the IDEAL soultion but if a WORKING SOLUTION i can acheve with what i have without throwing loads of cash at it, it's a solution that'll be inplimented rather than candels

If you ran a 12v distribution, to be fair you *could* just power a normal battery charger from the 240V output of the genset .. that would cost almost nothing and would be super simple to setup. you would have to run the genset for longer and apply a bit of human logic to making sure you put enough charge in to do what they want. I assume your cells are telco like the Hawker powersafe etc, they charge and survive ok if you keep them above 0c - I have a 48v string here that I acquired in 1999 and they are still perfect. I charge them ( 12 V ) with a 13.38V constant volt supply which is the ideal float voltage at 15c

Whatever crude ( meant in a nice way ) setup you decide upon can be made to work fine but as a bare minimum a low volts disconnect would be important as the user most likely wont shut down at the right time.

Maybe start of simple and refine it as you work out what the user wants after they have lived with it for a bit

 

[Justme]

I read the opening post but not the rest so forgive me if its been covered already.

You need to know how much energy you will be using per day before you can design a system to supply it.

We have been off grid for over 6 years.

 

[normspanners]

Just a little point re ac1 there is a debate that they dont like side thrust on the mains ie belt loading, which is why I put two alt's on mine 240 and 12v but apposed from each other to neutralize the pull.

 

[dannyp]

enigne wise it's looking like i'm proaby best off looking for some form of small kubota or yanmar lump. as the more i hear about them the more of a bad idea the AC1 sounds like

power requirements, if it can run a fridge, TV and a few lights and charge the usual portable clutter ( laptop, ipad and phone ) that will proably do. with the genny off. with the genny running washing machene is going to be the killer but seperate genny is allways an option for that.


so for chargeing a stack of batterys, 12v wants 13.38 volts so if i can tweek a 24v alternator to output 26.76 volts i'm part way there. the unit i have in mind is a 24v 80 marene unit so it's desinged to put up with some work. if the output goes anything like a car alternator would i be right to expct it to output around 28.8 volts. hopefully that is enough headroom to allow some chargeing controll.

how to controll it is going to be the challenge from what i can see at the moment, im guessing from whatever i use to controll it i need to potential limute the chargeing current and defantly regulate the chargeing voltage.

i'm wondering as my supply voltage is above battery voltage would a simpel PWM solar controller do ? or do i really need to build something for the job ?

 

[normspanners]

daft as it might seem you are better with higher voltage because standard alt set up dont fully charge batteries they only go to about 80 % and most of that is thrown in fast after start up,bulk charging then tails off so you are running and running the engine for very little actual charge, the absorption stage, some alts have a thin feed back wire that senses actual battery voltage, and adjusts charging to suit, one of those types is good coz you can play with that line, back to the reg, on the actual alternator adjusting the charging amount so by making that feed back line voltage lower, the alt increases the charge.
A good source of info is found on boating forums re battery charging it really is a minute difference in charging voltage that makes the difference there is also a pulse charge method where high voltage pulses are thrown at the battery that charges it quicker buts helps stop gassing.

read this http://www.chargingchargers.com/tutorials/24-volt-charger.html

http://www.homemade-circuits.com/2012/05/battery-desulfator-circuit-explained.html

 

[normspanners]

enigne wise it's looking like i'm proaby best off looking for some form of small kubota or yanmar lump

Yes go water cooled and as said utilize the heat produced for DHW and water heat mass storage. where you use that all important heat you have generated and paid for in fuel to store it in an insulated tank. just have the ign through a tank stat, that shuts engine off at 95 degs
As my mate proved an old small engined non turbo diesel car is a very cheap way to go. And saved him thousands in fuel. I was going to run a 240v genny off the front hub by locking one wheel that effectively doubles the speed of the other hub and easy to make a pulley to go where the disc fits or direct drive it. then it is easy if you dont want the 240v leave it out of gear. you can then use the ABS pulses to regulate throttle to set gen frequency.

 

[HughF]

buy a sterling advanced alternator regulator (about £100 quid) and then you will get 3 step charging at proper voltages from your alternator...

 

[Shox Dr]

If at all possible I wouldn't have a fridge. After reading the meters every week for the last 9yrs, the biggest consumer of power is the fridge, and then the freezer. Together they use 60% of our power

Not much needs keeping below 5c, and that can be done with a cold store or pantry.

 

[normspanners]

If at all possible I wouldn't have a fridge.

AGH we have two freezers 3 fridges and a fridge freezer.

 

[GW8IZR]

AGH we have two freezers 3 fridges and a fridge freezer.

Similar here., two chest freezers in an outbuilding, an inside freezer and a fridge, and yes they do take some running *but* we freeze loads of fruit and some dead 'stuff' to keep us going through winter.

Whether its an efficient system is debatable but it works for us.

 

[dannyp]

buy a sterling advanced alternator regulator (about £100 quid) and then you will get 3 step charging at proper voltages from your alternator...

do they actualy work or are they an overpriced empty box ?

 

[HughF]

They work just fine...

 

[HughF]

If at all possible I wouldn't have a fridge. After reading the meters every week for the last 9yrs, the biggest consumer of power is the fridge, and then the freezer. Together they use 60% of our power

Not much needs keeping below 5c, and that can be done with a cold store or pantry.

We have a mains fridge, A+ rated bosch, it contributes to about 50% of our 2kw/hr per day usage. I don't think it's a massive power hog personally.

 

[Shox Dr]

We have a mains fridge, A+ rated bosch, it contributes to about 50% of our 2kw/hr per day usage. I don't think it's a massive power hog personally.

Really.
I would, just to keep your milk cool

 

[Robotstar5]

If at all possible I wouldn't have a fridge.
Not much needs keeping below 5c, and that can be done with a cold store or pantry.

We kept our dairy products cool in the pantry in the 60's, even had a pupose made meat safe