48V battery bank controller

[(unknown)]

I have a 17' 48V 3-phase wind turbine that I built and recently picked up a 480V 1000A rectifier that I picked up for a song and dance.  Now I am looking for a controller for a 48V 660AHr battery bank.  My diversion load is going to be a hot water heating element.

I have seen some inverters that have controllers in them but am not certain if this is the way to go.  Any thoughts as to how I might proceed?

Thanks

[birdhouse]

beowolf-

i'm pretty sure the mornigstar controllers are pretty good and reliable and do 48 volts.  ts-60?

as far as the hot water heater doing the dumping, you might need to rethink that.  with a 17 footer you'll need plenty of dump and a hw heater is 220 volts, so it wont dump the same watts at 24 volts.  try and find a bunch of nichrome wire and you can build a nice robust not too hot dump load for yourself.  gizmo at the back shed has plans to do this pretty easily.  

you're well on your way!

birdhouse

[ghurd]

If you want to heat water, you need 2 controllers and 2 loads...

A 17' can make ~6000W?  It will not take long before the water is too hot.

Then the water heater shuts off (or it needs to shut off).

Then there is nowhere for that 6000W to go, except to a second dump load.

Probably need 3 controllers if the plan is to heat water.

One to heat water with up to 60A.

Two more to dump to other loads, up to 60A.

The problem is most good quality controllers only handle 60A, and a 17' 48V can make more than 100A.

G-

[Beowulf]

Hi ghurd,

Yep, ~6000W top end and then the stator goes boom.  But it would be more like 125A when it does it imitation of a shooting star.

My thinking was to have multiple water heating elements as it would go into a ~800 gallon hot water storage tank (and thats a lot of water to heat up to 100 degrees or more.  That hot water would go to my radiant heat system in the 2800 sq ft workshop/home.

My thinking was to wire three 22 amp hot water dump loads in series which would have a line run of ~75' to the tank (this brings in another queston:  should it be a DC or AC dump).  But my concern was that most of what I have been reading is that the dump load should not exceed 70% of the max amperage of the controller.  Is this thinking wrong?

If I do as you suggest how would connect the three controllers?  And what controllers would work in the series or parallel how would I connect them?  

I was thinking of having three banks of 8 6V golf cart batteries (48V) and wiring them in parallel to up the amp hours.  How would your suggestion change this?

Thank you for your time and knowledge.

[ghurd]

What will you do in the summer, when you do not want the heat?

"wire three 22 amp hot water dump loads in series".  I trust you mean parallel.

I believe dump loads in battery systems should be DC.

I have done some AC pre-dump-load circuits with a very wide hysteresis (nearly an LVD but set to a higher voltage) operating AC loads, but they were fairly unusual circumstances.

For you, it would require a second inverter with a huge rating.  Not sure it would be cost effective.

If the AC load's inverter blows up or something, the system is stuck without a load or way to do a temporary load.  Would basically have to turn on all the lights, TV, wash a load of laundry, and anything else to use up power with the primary inverter...

If a DC controller blows up, can do some temporary hard wiring, baby sitting, and hope for the best.

The 70% probably depends on the manufacturer.  I would tend to agree with it, but consider 70% a bit conservative.

I am not intimately familiar with the giant controllers in parallel.

The TS-60 can be paralleled, and should operate and react fast enough to keep things under control.

I figure you saw some of the problems related to delayed reaction times in C60s, and 125A going into 660AH of fully charged batteries could have some serious voltage swings.

G-

[Beowulf]

Thanks for taking your time to reply....................good info!

"What will you do in the summer, when you do not want the heat?"

Good point!  Have to think about that one for a while.....maybe a air diversion load can be wired up and put on the outside of the shop that allows me to switch between the two.  Your thoughts?

"I figure you saw some of the problems related to delayed reaction times in C60s, and 125A going into 660AH of fully charged batteries could have some serious voltage swings."

Nope did not see this info but I can see where it might be a problem.  Do you have a link to that info?  I will see if I can find it through a search.  Also, any suggestions on to how to resolve this issue?

[ghurd]

An "air diversion load" is fine, and what most people with Giant systems use, AFAICT.

"Nope did not see this info but I can see where it might be a problem... link?"

Not really.  It is spread out all over the internet.

And I am not sure what I read on the net or get via email.

Not overly uncommon for over voltage batteries to OVD (meaning Disconnect from Over Voltage conditions, and completely disconnect any AC loads, letting the battery voltage go up like a rocket).

Not unheard of for the battery voltage to go SOO00oo high, the OVD'd inverter has more voltage on it's input than it was designed to handle (even in OVD conditions) and the inverter is smoked.

And the condition does not require a 17' to do it.

Not many 17'ers around.

dlenox comes to mind, and he published his issues with controllers here on FL.

http://www.fieldlines.com/story/2009/3/19/165655/623

Dan now has a software item that can do more things.

G-

[oztules]

When it gets up to temp..... just short it out. Thats what I do with my electric car. For this application I can see no good reason to let it run.

Build the stator strong. I use 9 1/2" bolts to hold it.

.............oztules

[mercurybird1969]

Morningstar is what most everyone is going with these days. Thats what most of the experts recommend http://Http://Hurricanewindpower.com has a good deal on them