Big Battery for Inverter

[kltrider]

I stopped at a freight salvage house this (tuesday) afternoon on the way home from Atlanta.
I found a Deka AGM battery intended for back-up use in cell sites.  285 AH and it could be
connected as anything from 2 volts to 48  since it has 24 individual cells. At over 700 Lbs.
this isn't something I'd want to move often. Certainly made my F250 ride better.
What I need to know is: If I had the choice of inverters, which I do for a nice change,
which ones to consider buying? Does anyone have opinions on specific brands? I
know Xantrex is rated highly, as are a couple others.
Any real experience to provide ammo for a choice?

[okiezeke]

Ran a Xantrex for 5 years on the boat.  Seemed very heavy duty.  Survived a few lightning near misses with ease.  Let me assure you, you've never been close to lightning until you've been in a squall off shore with lightning hitting the water all around you, wondering why it doesnt hit your 50' metal mast.  Never did.
Zeke

[rmchambers]

Ditto on the Xantrex/Trace inverter.  I have one I got off a guy on Ebay that lived up the coast from me so I picked it up a bit cheaper than normal due to shipping.

My unit is a DR2438 which is a 24 volt 3800W nominal (4000something surge) inverter.  30 Amp battery charger too with a 30 amp passthrough so you need a 60 amp breaker for it to go hog wild on your power supply.

It's a pretty simple design - 24 volts in, 120 volts in and 120 volts out.  It runs with a modified sine wave which runs my computers without a problem.  I have two banks of 6 volt (4 of 'em) Trojan golf cart batteries on it so now I've got a pretty decent runtime.  I'm still in the process of (a) finding out what the electrical inspector will want to see and (b) deciding what is critical and put a sub panel in for those circuits.

There are more expensive Xantrex units, like the SW series which make a lot cleaner sine wave power but for the most part most devices run ok on the modified sine wave.  If you want 220 you have to gang two of them together with a stacking cable.  Nothing I have that I consider or am considerint to be critical needs 220 (dryer, stove, A/C compressor) so I am not bothering with finding another one.

The SW series also have more guzintahs  - like a guzintah for a generator feed, etc and it has contact closures for starting a generator when it sees the batteries are getting below a certain threshold of discharge.  It's pretty slick really but you pay for it.

The Xantrex website is pretty good and the documentation for their series are downloadable as PDF's.

Robert

[rcavictim]

I`m in the process of sorting through a bunch of telco surplus AGM, 105 AH, 12 volt batteries that I recently obtained through favor of the gods. These are used but still have about 1/2 storage capability left and with care ought to give me another five years I hope.  I am currently welding up some stands to hold them all in a useable configuration.  I plan to start with 48 batteries hooked up making two completely separate circuits.  A very high current 12 volt parallel string (likely 16 batteries at first because my racking will have that many side by each in each of three rows and this makes it easy to hang each on a massive copper buss, individually fused) that will supply three Xantrex X-power 1000 watt Mod sine wave inverters which I bought new, and a 48 volt plant of parallel strings (four batteries per string) that will power a computer UPS used as a 2250 watt, 120 volt output sine wave inverter.  I have 120 to 48 volt telco style float chargers to handle the 48 volt strings in two sections.  I need to acquire or fabricate a heavy duty 12 volt float charging supply.

This accelerates my need for a working wind turbine or photovoltaic solar panel roof.  I accept charity.   

[captfred]

The commercial boat I'm operating has been running a Trace Inverter 24/7 in tropical heat and humidity for over 10 years with out a hitch.  Nuf said there.

In my home I've  run a VFX3524M (vented marine  3500watts/24volt DC) Outback true sine-wave inverter (with integrated battery charger) and 2 banks of T105 batteries for over 3 years.  Over the past 2 years we have experienced serious  island generation  problems which have lead to hundreds of brownouts or blackouts.  My household power has not once gone out in those 3 years.  Nice thing is there's no need to start a generator, the kicks in inverter automatically-  my wife loves the bloody thing.  When power wanders beyond prceset parameters Hz or voltage the inverter cuts off the island power and runs on batteries until the power stablizes.  No more need for battery back-ups for computers.   I run lights, UV sterilization, tv,  computers, refer and 5000 btu A/C with no problems.
 
Any alternative energy generation system will always require a  standby generator (for when the wind or sun isn't available).  My listeroid is the secondary component to my alternative energy system (the primary part was my inverter batteries).  After my listeroid is up and running reliably, my next project is the tertiary component will be wind generation; hope to get that  up and going by the end of the year.

Anyway, can't say enough good stuff about inverters- do your research and go with what you feel fits your needs; Trace/Xantrex or Outback I can't praise either one enough. (BTW Trace was bought out by Xantrex;  Outback was started by a group of Trace engineers who thought they had a better idea).

Cheers, Fred

[spike]

Although the sine wave inverters are more expensive and a little less efficient, they don't make that 60 cycle buzz on your AM radio, tape deck or electric guitar. Just something to consider.

Tim

[rcavictim]

Although the sine wave inverters are more expensive and a little less efficient, they don't make that 60 cycle buzz on your AM radio, tape deck or electric guitar. Just something to consider.

Tim

Tim,

The quality of output filtering inside the modified sinewave inverters may vary between brands.  I know for a fact that some audio amplifiers are better shielded against line noise than others as well.  I have run my home stereo tube amp from my Xantrex X-power 1000 and it is absolutely black silent in very high efficiency speakers (100dB/1W/1m) that really show off low level hum and buzz if there is any.  The power xfmer in my amplifier has a copper faraday shield between the primary winding and the secondary windings.  Your guitar amp power xfmer probably doesn`t.  It is probably possible to make your amp more immune to line noise by adding some filters.

[spike]

My guitar amp wasn't the problem as the buzz was only when my guitar was plugged in. I did solve the problem (besides turning up the distortion) by upgrading from a Trace modified sine wave to a Trace pure sine wave. But now, sadly, I don't seem to have time to play anymore.....maybe that's best for everyone. 

Tim

[kltrider]

Thanks for all the input folks. I will be making my decision this weekend, after I
deposit the checks from my last batch of customer sets. It looks like 2 Xantrex
SW2524s in a stacked configuration is my best bet. BTW, I bought 2 DEKA
Legacy fork truck batteries today for trade-in price from the plant where I work.
96 volt wet cell packs in steel containers. This is the perfect place to try out that
de-sulfater / charger I bought last month.
Thanks again, Wayne.

[rcavictim]

BTW, I bought 2 DEKA
Legacy fork truck batteries today for trade-in price from the plant where I work.
96 volt wet cell packs in steel containers. This is the perfect place to try out that
de-sulfater / charger I bought last month.
Thanks again, Wayne.

I was considering used forklift batteries too until these decommissioned telco units came along first.  Forklift batteries have heavy lead plates and are designed to spend their entir life being deeply cycled.  They are probably as good as you can get in a battery for off-grid inverter use if they are still good.  Not the easiest things to handle however in a home environment without a loading dock and forklift.   

I would like to experiment with a pulsing type de-sulfator. It would be very helpful to reclaim more capacity from my load of tired lead.  There is one I`ve seen that takes the power to run itself from the battery it is being used to treat.  What did you get Wayne?

Curious, what is trade-in value for a forklift battery?  Do you know the AH rating on your`s?

[kltrider]

RCAVICTIM:
They are not necessarilly 96 volts as I originally thought. These have 985 AH at an 8hr. rating.
Yes they are heavy and clumsy but they should be able to run a house for 24 hours or more.
Taking a better look I see that they are setup as 4 24 volt groups and could be used as smaller units.
by re-connecting the cells differently.
Incidently, they were pulled out of service because they wouldn't run the for 18 hours without a charge.
They needed to be plugged in after 14 hrs. of continuous service. The fork lift still ran, but slowed down
too much for loading a heat treat furnace.
I should have looked closer and would have seen that some of the interconnects were removed,
possibly for use on the replacement. I paid $300. for each.
I called the Clark dealer this morning and was told that the trade in was based on what the dump,
excuse me -recycling center- , would charge to take them.
I bought a Pulse desulfator and will likely spend time this weekend setting this up.
Best to all: Wayne.

[rmchambers]

The Xantrex/trace inverters have a couple of settings for "equalize" basically it throws more volts at the batteries than they like and forces the plates to bubble off a bit.  The effects of this are twofold:  1. hopefully knock off the sulphate crystals and 2. cause the acid/water mixture to de-stratify (which supposedly happens after a while).

I've done it to my old battery bank after measuring different numbers for each 6V cell.  After the equalization charge the numbers are within a tenth of a volt of each cell so I have to assume it works.

The pulse desulphators seem to be a pretty neat idea, just make sure they are hooked up to the right polarity or it lets the smoke out.

RC

[rcavictim]

RCAVICTIM:
They are not necessarilly 96 volts as I originally thought. These have 985 AH at an 8hr. rating.
Yes they are heavy and clumsy but they should be able to run a house for 24 hours or more.
Taking a better look I see that they are setup as 4 24 volt groups and could be used as smaller units.
by re-connecting the cells differently.
Incidently, they were pulled out of service because they wouldn't run the for 18 hours without a charge.
They needed to be plugged in after 14 hrs. of continuous service. The fork lift still ran, but slowed down
too much for loading a heat treat furnace.
I should have looked closer and would have seen that some of the interconnects were removed,
possibly for use on the replacement. I paid $300. for each.
I called the Clark dealer this morning and was told that the trade in was based on what the dump,
excuse me -recycling center- , would charge to take them.
I bought a Pulse desulfator and will likely spend time this weekend setting this up.
Best to all: Wayne.

Wayne,

You paid basically what an outfit in Toronto was offering used FL batteries for in a newspaper ad.  Seems to me that your company should have paid YOU the $300 each to take them according to what you reported.  These should NOT be going to landfill, no matter what money is being slipped into the palms of those running the dump site.

I sure hope the missing jumpers are indicative of being re-used in the new battery install and not as a result of cells being eliminated from the circuit during their time on the last machine as they went bad.  If that is the case they will be badly sulfated and beyond use.

Please tell us more about the pulse desulfator you bought.  Is there a website describing it?

[kltrider]

RCAVICTIM:
Talking to both the folks at work, and the FT dealer, I figured out that the $300. was a nominal number that was built into the purchase price of a replacement battery
based on what the value was at the dump. The value / price there is set by the operator of the dump according to a formula set up by the county, which owns the place.
I will get more into this as I go along.
The cell connectors were definitely re-used on the new battery.
I got my PULSETECH unit, it says on the lable. They are supposed to have a web site, but I haven't gone there yet.
I reconnected the cells into 12V blocks to re-cover / re-commision them, then will connect them into 24V packs to run the inverter at my Moms place.
I will build a couple of small carts to be able to swap them out easily during extended power outages. Use 1 there and bring the other home and charge it overnight, then swap again when needed.
There must be a high frequency sound comming from the pulser. Tripod, the three-legged Dawg, and Tipsy the also three-legged Kat are both sitting there staring at it in the classical pose, looking straight ahead with their heads cocked slightly to one side.
So cute it makes me want to cry!! 
I'll keepyou posted.
Lots of good will, Wayne.

[Tom]

Capt Fred,

Question about your outback inverter. Does it hum when it is on? I have a Trace sw2512 and it works great, but it hums while it is on. I will be purchasing a set of inverters soon for our off grid home which is currently under construction and have to make a decision soon about the inverters.