Batteries, Inverters and building on

[cregy]

Hi

I have no real knowledge of where to start and figured I might get better independent advice here rather than ringing a company. I am a youth worker and we have been given a £1000 grant to start building an off-grid system. It really is only the start we will be applying for further funding to move us on.

We already have a generator (recoil) but nothing else. We want to power lights at the start. We will need to power a small sound system and video projector and also charge power tools.

We have no access to mains electricity.

Where do I start please? What questions do I need to answer or can someone recommend a battery, an inverter, the checking system? Eventually we want to have pv cells and several batteries enabling. Imputed use, washing machines and 240v power tools.

Thanks

Rich

[knighty]

£1000 is a very tight budget for what you want

I think you'd be best off running a cheap battery charger from your generator charging a couple of leisure batteries

use 12v lights and hunt like crazy for a cheap inverter


you might be best off running the generator any time you need 240v power, and just using the batteries for lights for now



at a push I guess you could get an old forklift battery pack, a charger and a cheap inverter for under £1000... but it's a bit tight

the problem is you'll need a decent inverter to run the sound system and projector (i.e. not a cheap ebay one)


being a youth worker you might be able to beg and get a few freebies or bargains ?

[rogeriko]

APC ups's over 1000va are pure sine wave and will run everything. All the cheap inverters on the market are square wave or modified sine wave and they will not run motors etc. Stay away from cheap inverters. On E-Bay you can find many APC ups for next to nothing and if you open them and add extra batteries they are perfect for what you want. I ran my whole house on one for a year. Charge the extra batteries with an external 24v charger because the ups charger is very slow. Garages like to change truck batteries before the end of their lives because it ups the bill and their profit. Start scrounging some big batteries 200Ah+ buy a sine wave ups and a 24v battery charger and your in business. Probably for half of your money. This is what you want one of these will give you 1kw sine wave from 24v battery.

[Andy the Inverter Man]

Hi
I convert the APC UPSs to be used as inverters.
Drop me an email if need any.
I actually have a load of the very same ones as pictured in the previous message by rogeriko.
I also have a couple of 12v 100Ah batts for sale.

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[biff]

As Roger says,
                  1000watt @ 24volt is a very handy setup.You can do an awfull lot with !000watt and it is sine wave where everything works as it should.Running a 12volt system requires very heavy leads and wiring.I did install an 800ah yousa battery bank about 6 years ago,it is charged off 2 x 80watt solar panels and powers  a little 600va smart ups @12volt=400watt.You would be surprised how efficent and reliable this little system has been down through the years. At the end of 2010(i think) we had a big freeze,-15 and the outside battery banks,the forklift battery refused to work under -8.we did have bright sun and for 2 weeks all we had was the little 400watt backup system and our generator.
we managed fine,starting the generator after dark and charging into the 800ah bank untill midnight,to run the house overnight.
                                                                                                                           Biff

[cregy]

APC ups's over 1000va are pure sine wave and will run everything. All the cheap inverters on the market are square wave or modified sine wave and they will not run motors etc. Stay away from cheap inverters. On E-Bay you can find many APC ups for next to nothing and if you open them and add extra batteries they are perfect for what you want. I ran my whole house on one for a year. Charge the extra batteries with an external 24v charger because the ups charger is very slow. Garages like to change truck batteries before the end of their lives because it ups the bill and their profit. Start scrounging some big batteries 200Ah+ buy a sine wave ups and a 24v battery charger and your in business. Probably for half of your money. This is what you want one of these will give you 1kw sine wave from 24v battery.

Thanks for the reply. I talked to someone today who advised me re the pure wave technology and could provide a new inverter for £550. He also quoted £250 for batteries. He wanted me to do calculations with all the equipment I use and ampage etc. I could increase the budget if that would help. It just comes from a different fund! Would that help. That said the system you talk about above seems perfect. Is there a flaw somewhere?

The problem I have is getting funding again if I do something wrong! I will get funding for solar panels within the next year or so.

Thanks for the help.

Rich

[Andy the Inverter Man]

APC ups's over 1000va are pure sine wave and will run everything. All the cheap inverters on the market are square wave or modified sine wave and they will not run motors etc. Stay away from cheap inverters. On E-Bay you can find many APC ups for next to nothing and if you open them and add extra batteries they are perfect for what you want. I ran my whole house on one for a year. Charge the extra batteries with an external 24v charger because the ups charger is very slow. Garages like to change truck batteries before the end of their lives because it ups the bill and their profit. Start scrounging some big batteries 200Ah+ buy a sine wave ups and a 24v battery charger and your in business. Probably for half of your money. This is what you want one of these will give you 1kw sine wave from 24v battery.

Thanks for the reply. I talked to someone today who advised me re the pure wave technology and could provide a new inverter for £550. He also quoted £250 for batteries. He wanted me to do calculations with all the equipment I use and ampage etc. I could increase the budget if that would help. It just comes from a different fund! Would that help. That said the system you talk about above seems perfect. Is there a flaw somewhere?

The problem I have is getting funding again if I do something wrong! I will get funding for solar panels within the next year or so.
Thanks for the help.
Rich

Hi
For £550 I could do 6 or 7 of the APC UPSs mentioned in the previous message.  They are 950 watts (1400va) each and 24Vdc.
What was the wattage of the one you've been quoted for?

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[cregy]

Hi

Thanks for all the replies. It is exciting to know that we are closer to having a system set up.

I have spoken to Andrew earlier on and he suggested that I post details of the generator:
http://www.justgenerators.co.uk/pages/PramacE3200.htm

With the budget I have would I be able to include a solar panel as well please? With the kit I am looking to buy of Andrew I would need a 48v direct current one. I would probably have around £500.

Thanks for all the help.

Rich

[Andy the Inverter Man]

Hi

Thanks for all the replies. It is exciting to know that we are closer to having a system set up.

I have spoken to Andrew earlier on and he suggested that I post details of the generator:
http://www.justgenerators.co.uk/pages/PramacE3200.htm

With the budget I have would I be able to include a solar panel as well please? With the kit I am looking to buy of Andrew I would need a 48v direct current one. I would probably have around £500.
Thanks for all the help.
Rich

What I suggested was checking the o/p of his genny was a steady 230VAc.  I believe some gennys have rather varying Vac o/p relative to load.

For the inverter I have suggested a 3kva/2.2kW 48Vdc unit.  Hence the solar panel(s) and regulator need to be for charging a 48Vdc battery bank.

Regards
Andy the UPS, Inverter & Battery Man

[rogeriko]

To charge a 48v battery you will need 2 solar panels wired in series, most solar panels are 29/30v Mpp(mean peak power) A 48v battery needs 60 volts to charge it full. With the money you save by buying the UPS not the inverter you could buy 2 solar panels. Ivan has some for sale cheap check his recent posts.

[Andy the Inverter Man]

To charge a 48v battery you will need 2 solar panels wired in series, most solar panels are 29/30v Mpp(mean peak power) A 48v battery needs 60 volts to charge it full. With the money you save by buying the UPS not the inverter you could buy 2 solar panels. Ivan has some for sale cheap check his recent posts.

Do the solar panels come with a regulator for charging the batts at the right voltage?
Andy the UPS, Inverter & Battery Man

[billi]

sure a  1000  GBP do not buy a lot  


Buy 1-2000   watt of PV first and then ask  for more cash , cause no clue  ,what to do with 2000 watt  PV

 
And ask for a more efficient Inverter  then  

[cregy]

To charge a 48v battery you will need 2 solar panels wired in series, most solar panels are 29/30v Mpp(mean peak power) A 48v battery needs 60 volts to charge it full. With the money you save by buying the UPS not the inverter you could buy 2 solar panels. Ivan has some for sale cheap check his recent posts.

Do the solar panels come with a regulator for charging the batts at the right voltage?
Andy the UPS, Inverter & Battery Man

Hi Andy

I have contacted Ivan and he has suggested a route to go down that will be fine. I need to purchase a good MPPT charge controller to do the work. The genny does not output clean and would need to work through the inverter if we used it direct. Alternatively just use it to charge the batteries but as I am buying 3 pv cells it might be surplus!

Thanks

Rich

[Andy the Inverter Man]

To charge a 48v battery you will need 2 solar panels wired in series, most solar panels are 29/30v Mpp(mean peak power) A 48v battery needs 60 volts to charge it full. With the money you save by buying the UPS not the inverter you could buy 2 solar panels. Ivan has some for sale cheap check his recent posts.

Do the solar panels come with a regulator for charging the batts at the right voltage?
Andy the UPS, Inverter & Battery Man

Hi Andy

I have contacted Ivan and he has suggested a route to go down that will be fine. I need to purchase a good MPPT charge controller to do the work. The genny does not output clean and would need to work through the inverter if we used it direct. Alternatively just use it to charge the batteries but as I am buying 3 pv cells it might be surplus!

Thanks
Rich

Hi Rich,
I'm a bit confused here.....
Lets start with the genny.  2 questions....
Does it output a good sine wave?
And does it output a steady 230Vac (or does the voltage vary with load)?
By what you've said I presume the answer to both questions is 'no'?

Now for the inverter (UPS).
There are 2 types of inverter/UPS technology (double conversion and line interactive).
One WILL work with a genny with poor output and the other may not.
Double conversion will accept a wide range of voltage from a genny and also it doesn't have to be a sine wave from the genny.
Line interactive needs something close to a sine wave from the genny.

A 3kva/2.2kW line interactive inverter/UPS will work with a 48Vdc battery bank.
But a similar size double conversion inverter/UPS typically needs a battery voltage of 96Vdc.
So the important thing here is the inverter voltage needs to match the solar panel voltage!!!

So the questions you need to ask your genny supplier are....
1) What AC voltage does the genny output for no load, half load and full load?
2) Does the genny output a clean sine wave at all times?

The answers about the genny will effect the type of inverter/UPS you go for.
Can you post the replies to the questions on here?

Regards
Andy the UPS, Inverter & Battery Man

[cregy]

Hi Andy

I'm just asking the question re the voltage but know the answer to the second question. No. If I wanted to I would have to put it through the inverter or an AVR.

Will let you know once I have heard back about the voltage output.

Thanks

Rich