Battery bank

[nuttyprofessor]

Hi Guys,
Haven’t been on here for ages...just shows how well the ST3 has been running.
Right... I’ve now managed to get hold of:-
12 x Yuasa Endurance EN160-6, 6 volt, 160 amp hour batteries. And a 48volt rectifier. (from a computer ups)

At the moment I’ve got 8 batteries charging off the rectifier and a 12volt inverter producing 220volts for use in the cabin (every day I swap the inverter to another pair of batteries to keep the discharge equal)
 
Can anyone tell me the best way of setting up a system which charges of my 10kva(maximum) generator?
Don’t mind if I have to buy new inverter and charger or how many batteries I use at whatever voltage. Cost and simplest system is what I’m after.

Suggestion’s greatly appreciated.

[mike90045]

....
Don’t mind if I have to buy new inverter and charger or how many batteries I use at whatever voltage. Cost and simplest system is what I’m after. 

What is your load that you need to power ?    Mod-Sine, or Pure Sine output ?  120V or 240V

To utilize your 10KW output, you will need a Humongous Battery.  If you don't mind loading to 60%, you can use a giant battery.   Generally, batteries charge at 5-15% of their 20 hour capacity sticker. A 100ah battery should not be hit with more than 15 amps.
 My 48V, 800ah bank, should see about 80 amps at charge.   That's about 4KW of power.

Look for an inverter that has a built in transfer switch, with a high efficiency / Power Factor (PF) spec.
 1.0 = perfect, .9 is great, .6 is lame, but that's what most gear is.

Figure for every 1Kw of load on the inverter, you need to add 12V to the DC chain:
0 - 1Kw = 12V
1-2KW = 24V
over 2Kw = 48V  When you figure out the amps drawn, the voltage loss in the cables and the sag in the batteries, 48V systems look very good.

Hope this helps

[Sfene]

Do you need AC at all? Motors etc?

If not, 20 6v batteries equal 120v +or-.

you can run incandescent lights and even some motors off of this....

Electrical Substations run off of 135V dc for control power and to operate Motorized Disconnects.

Maybe you can eliminate AC entirely...

Sfene

[LowGear]

Holly Molly Sfene,

Maybe you can eliminate AC entirely...

Did you read that Edison?  Perhaps you'd take a minute and tell us what your doing with your DC system?

Casey

[nuttyprofessor]

Maximum load for the majority of the time will be less than a KW but it would be good if I had upto 3 KW on standby.  Pure sine 220/240 AC.
If I stick with the battery bank I’m running at the moment its spec’s are
48 volt 1280 amp hr how long would it need charging and at what amps?

What I want to do is run the generator for as little time as possible (price of fuel now).
I’m really not sure what I should be doing to build the most efficient system and need someone to tell me how my batteries should be set up... 12, 24, 36 or 48volt and then what I need to charge them.
When I look on ebay there are plenty of inverters but none of them seem to have a high enough charging amps.
Help... I’m now paying 1 euro a litre for red derv and running the genny for around 8 hours every day.
Would I be better off getting a 24volt truck alternator, bolting it to the genny and charging the batteries this way?
Thanks for the help.

[mike90045]

a 48V 1280ah bank, flooded cells, not AGM, would like to see about 130A of charge current. (10% of sticker capacity)  The largest charger I know of, is in the XW6048 inverter/chgr which can deliver 100A @ 48V.  Otherwise, you need to locate a 3 stage forklift charger.

100A @ 48V is 4800 watts - that's going to need to be hard wired to a serious supply, at 240VAC, it's 20A.

--
voltage drop calculators:
http://www.solarpaneltalk.com/showthread.php?2312-Wiring-interconnect-goodies-amp-volt-drop-loss-calculator

solar: http://tinyurl.com/LMR-Solar
gen: http://tinyurl.com/LMR-Lister ,
battery lugs http://tinyurl.com/LMR-BigLug
Setting up batteries http://tinyurl.com/LMR-NiFe

gear :
Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV !
| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine 300W inv | Sunsaver MPPT 15A |

[nuttyprofessor]

Hi Mike, thanks for the help.
I live in France and have no mains electric, I’ve now been running off a generator for 6 years so I’m used to only having electric for around 8 hours a day. I have a VERY limited budget so can’t go spending 1000’s on inverters etc.
Since your last message I’ve located a forklift charger (48 volt) but it needs 51 amps and there’s no way my genny is going to run that, the genny is a maximum of 10kva /8kw.
After seeing how much power I need to charge my battery bank I think I’m gonna have to re think things.
All I really need from my batteries is around 8 hours of power at no more than 1000watts (most of the time less than 500 probably)
As you might have guessed I’m really confused about what I should do.........
I’m now thinking of only using 4 out of the 12 batteries to create 24 volt 640 ah so I won’t need such a big charger, 50amp I’m guessing will be enough. 
What do ya recon ?
I’m waiting for permission to put up PV panels so will use the rest of the batteries then.
What are flooded cells? What is AGM?

[LowGear]

Is my math screwed up?

48 volts x 51 Amps = 2448 watts

Casey

"Math is hard!"  Barbie Doll

[mike90045]

Flooded cells.  Batteries that have a cap, where you check fluid level and add distilled water.  Needs higher charge rate to bubble the acid, to prevent it from stratifying, but not so high it damages the battery.

AGM.  absorbent glass mat   Cells are filled with chopped fiber glass and then acid added to keep it all wet, and battery sealed,  If overcharged, it vents an ruins the battery. Capable of very high performance.

48 x 51  IS  2448   What did I screw up ?  Mathz IS hard.

[LowGear]

Since your last message I’ve located a forklift charger (48 volt) but it needs 51 amps and there’s no way my genny is going to run that, the genny is a maximum of 10kva /8kw.

48 volts x 51 Amps = 2448 watts

Isn't that 2.448 KW?  What am I missing?

Casey

[nuttyprofessor]

Casey, 240v x 51amp = 12,240w ? The imput the charger requires. I'm new to this so happy to admit I could be wrong, if I'm not might it make you look a bit of a Knob...

My batteries are sealed so must be AGM?
http://www.enersun.com.au/files/PDF/Batteries/EN160-6.pdf
Does this make any differance to charging rates etc?

[mike90045]

Casey, 240v x 51amp = 12,240w ? The imput the charger requires. I'm new to this so happy to admit I could be wrong, if I'm not might it make you look a bit of a Knob...

My batteries are sealed so must be AGM?
http://www.enersun.com.au/files/PDF/Batteries/EN160-6.pdf
Does this make any differance to charging rates etc?

YES !!

1)  those batteries you linked to - are labeled for FLOAT application, like an emergency light, or computer UPS.  Not Deep Cycle service

2) Sealed batteries, AGM, can take a pretty heavy charge, till they are full, once full they start to gas, and that instant, charge must be cut back to float.  Or the gas forms faster than the cat can re-combine back to water, and the gas vents, and you loose water you cannot replace.   Needs 3 stage charger with battery temp sensor.

[LowGear]

Well all of us can do simple multiplication but where in this blue earth would they get charged at 12+ KW?  I mean if we drop that 240 volts down to 48 volts or say 53 volts where the battery is we're talking about 250 Amps.  That's some pretty fat wire.

How come I'm confused? 

Casey

[nuttyprofessor]

Are these batteries good for what I want to do with them?
They all hold a charge of 6.5volts+.They cost me very little not even scrap value do you think it’s best to invest the money to buy the proper charger for these or try and get my hands on the other type of battery.
These batteries came from the back up communications system of a very large pharmaceutical company when they moved and building was demolished. They hadn’t reached their service life.

Casey, I found a fork lift charger... the supply it requires is 240volt 51amp? In the UK?

[LowGear]

Hi nuttyprofessor,

If I worried about looking like a knob (?) I would have dropped quietly off this website many months ago.  Luckily there are a few rather knowledgeable contributors that try to help me along in my aspirations of understanding.  Life is much sweeter when you let go of your ego in a group of people you'll probably never actually meet or know. 

240 volts at 51 amps; Wow!  60 Amp breakers; Woof, Woof!  I've been thinking about how much work those electric fork lifts do when they're just moving to where they need to do the actual lift and carry stuff.  I wonder how many DC amps this charger puts across the battery?  You sure that charger isn't for a bank of batteries?  (Isn't it funny how the ignorant hold onto their misconceptions so tightly?)  You realize that this charger should be able to produce nearly  250 Amps at 48 Volts?

Casey