Author Topic: Inverter vs. generator  (Read 22087 times)

wlb

  • Newbie
  • *
  • Posts: 9
    • View Profile
Re: Inverter vs. generator
« Reply #30 on: October 28, 2011, 01:12:03 AM »
I'll be interested to hear how it runs with the XW.

Interesting collection of photos, thanks for the links.

My SL2 set is bolted directly to a solid concrete block which is perhaps 6" wider than the base of the genset all around, sits on the subsoil clay, and stands about knee-high.  Very heavy and stable, and easy to work on.  The shed floor around the foundation block is fine screenings.

The 8/1 belt-drive set sits on its original Lister cast-iron base.  This in turn is bolted to and fully supported by a heavy fabricated 4" steel RHS frame.  
Between the engine and the cast-iron base is a stainless steel oil drip tray with a drain spout at the end.
The steel frame sits on a heavy steel skid fabricated from the same 4" RHS, but is isolated from it by 6 large industrial rubber machinery mounts.

The engine will run quite happily with this whole assembly just sitting on the ground as the rubber mounts absorb all the vibration.  When installed, the skid sat on a floor-level concrete slab with a small 2" x 3/4" steel frame bolted to the concrete.  The slab had a winch achor point cast into it.  When originally installed at the ski lodge, we could winch the whole skid out of a trailer, up the side of a hill through the scrub (perhaps 25m) and into the motor shed.  The frame bolted to the slab guided the skid into position and a steel pin was dropped into place to prevent any possibility of the skid gradually "walking" around.  All that remained to do was connect the fuel line, exhaust system, and plug in the electrics.

When it was removed we just reversed the process.  It was winched out and down the hill onto a trailer.

It still sits on the skid so I will be reinstalling it at home using the same methods.
« Last Edit: October 28, 2011, 01:15:28 AM by wlb »

12 gauge

  • Jr. Member
  • **
  • Posts: 71
    • View Profile
Re: Inverter vs. generator
« Reply #31 on: February 01, 2012, 08:52:09 PM »
mike90045,

How are your NiFe batteries working out?  How do they compare with your lead/acid batteries?

Ron

mike90045

  • Mendocino Metro
  • Hero Member
  • *****
  • Posts: 1594
  • Mmmm BBQ
    • View Profile
    • Mikes Solar PV page
Re: Inverter vs. generator
« Reply #32 on: February 03, 2012, 05:19:13 AM »
mike90045,

How are your NiFe batteries working out?  How do they compare with your lead/acid batteries?

Ron

Currently, they are just idling along, the house is not built yet, no real work for them to do.   
The disadvantage is, they bubble water away at all stages of charging, not just absorb like lead-acid do.  Another issue, is a very wide range from full charge (final absorb cycle voltage) of 69V to 10% at about 53V.  About 2x that of lead-acid.  So I've had to not use the full voltage swing, and limit the Morningstat MPPT charger to 67V, below the shutdown voltage of the XW6048. So I only can get up to about 90% charge.    So anyone looking at NiFe - you need to be aware of the voltage range they run, and insure your charger and inverter can handle it OK.

12 gauge

  • Jr. Member
  • **
  • Posts: 71
    • View Profile
Re: Inverter vs. generator
« Reply #33 on: February 03, 2012, 06:28:06 PM »
Thanks Mike,  Can you use the caps that recombine the gas back into water?  I'm just watching for what is available, since my system of 2 volt lead cells are now about 40 years old.  They are still doing the job though.  It seems that the wide voltage swing may be the hardest to deal with, cause my inverter/charger doesn't have that much range of adjustment.
Ron

BruceM

  • Hero Member
  • *****
  • Posts: 3054
    • View Profile
Re: Inverter vs. generator
« Reply #34 on: February 03, 2012, 07:03:26 PM »
The water use is interesting, Mike.  I wonder if it would stop at a lower charge rate?  I have read that the Ni-Fe batteries must be charged slower (and discharged slower)- what's the specified charge rate on yours and how close to that are you? 


mike90045

  • Mendocino Metro
  • Hero Member
  • *****
  • Posts: 1594
  • Mmmm BBQ
    • View Profile
    • Mikes Solar PV page
Re: Inverter vs. generator
« Reply #35 on: February 04, 2012, 05:36:26 AM »

I've only got 3KW of solar, at 55V, I seldom push more than 25 amps. And winter days are shorter. (getting longer now though)   The batteries are spec'd about 825ah @ the 20 hr rate.  So, I'm way down on the charge scale. 
NiFe has higher internal resistance, and that can slow things down too.


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

BruceM

  • Hero Member
  • *****
  • Posts: 3054
    • View Profile
Re: Inverter vs. generator
« Reply #36 on: February 04, 2012, 04:21:29 PM »
Thanks for the good info, Mike.  I knew about the higher resistance, which I don't think is an issue for most higher voltage systems,  but the water use at modest charge rates is something I have not read about.

I think NiFe is generally a good match for many home power situations; I just wish the price would come down.  One more thing besides incandescent lighting and 120VDC for homes that Edison got right, in my book.   ;)

If they got more popular I'm sure the inverter designs would all accommodate the bigger voltage range.

For my 120V system even the smallest NiFe batteries were larger than I need, and because they aren't packaged in higher voltages, the cost, size and interconnections just got way out of hand.

Battery management for NiFe sure would be easy and a fuel saver.  Instead of always trying to keep the batteries topped off (to prolong life), you can start the generator only when they are nearly empty and just put in enough to get you to the next sunny day.


« Last Edit: February 04, 2012, 06:27:56 PM by BruceM »

12 gauge

  • Jr. Member
  • **
  • Posts: 71
    • View Profile
Re: Inverter vs. generator
« Reply #37 on: February 04, 2012, 06:46:33 PM »
BruceM,
Thanks for your insights also, Bruce.  And, BTW, I couldn't be happier with your AVR for the ST-5.  It has been 100% trouble free at this point.
All the best,
Ron

BruceM

  • Hero Member
  • *****
  • Posts: 3054
    • View Profile
Re: Inverter vs. generator
« Reply #38 on: February 04, 2012, 10:44:29 PM »
You're most welcome for the help on your homebrew AVR, Ron.  Mine is still going strong, too.

It's really great that Mike took the leap to NiFe. It takes guts to try something different from the run of the mill system.




12 gauge

  • Jr. Member
  • **
  • Posts: 71
    • View Profile
Re: Inverter vs. generator
« Reply #39 on: February 05, 2012, 06:58:02 AM »
Absolutely, thanks Mike.  I'd like to soak up all the info I can on NiFe, maybe I'll go that route when I need new batteries.  It appears the inverter/charger is the problem, (aside from the price) until someone makes one that can be adjusted to charge NiFe.