Battery Box?

[Peppyy]

Slowly but surely I am gathering what someday may turn out to be a complete R/E system.

I just picked up these beauties from the only battery dealer in 75 miles. They are 14 month old 225ah 6 volt floor buffer batterys. They have been cleaned, watered, inspected, charged and tested to factory specs by "Mr. Interstate" himself.

I paid $120 for all 4 ($30 each) Please don't tell me I made a mistake lol.

My

My question is about my "rack". I was planning on placing them on 2" blueboard on the garage floor. My garage is not heated so I was wondering if it would be a good idea to build a box out of blueboard and surround them to keep them warm?

My plan was to use a charge sensor, (Possible as simple as an analog amp meter with a set of contacts) to run a small computer fan to exhaust the gasses when charging over a certain rate. (10 amps).

Should I build a rack and raise them up off the floor farther? Space is at a premium and I have a spot under some shelves that would be great.

[TomW]

Peppy;

I think you definitely want to enclose them for 2 good reasons. First being safety since if a metal object gets across those posts it will be very interesting to say the least. Second would be to minimize temperate fluctuations. I also think getting them up off of the floor is good to help prevent a big temperature difference in the top and the bottom of the battery. Sitting on a concrete floor, for instance, will suck heat from the bottom of the battery.

I say nice score on the batteries if they are still near spec.

Cheers.

TomW

[jacquesm]

I'm on my second set of battery boxes here (the batteries are still the same), but mine are very tall cells so I had a 'bulging' problem due to insufficient stiffness in the original boxes.

Yours are packaged pretty good the way the are, you only need a box to protect them from stuff (metal !) falling on them and to be able to vent gases to the outside (those gases are explosive). Both of those are safety issues.

The simplest I can think of is a plywood box just a little larger than your batteries, with tbe bottom part reinforced by some 2x4's or so in case you want to move the box as a whole.

The lid should have a vent in it, with a tube that allows gas to go outside of the storage room (and out of the building) to avoid dangerous concentrations of gas during heavy charging.

Temperature is an issue, but it is more of an issue when the batteries are discharged, so keep an eye on charge state when it's cold, with a normal charge/disharge cycle when it's cold around the batteries a simple foam insulation layer on your box (maybe make it double walled) should keep thm well even when it is -30 celsius or so.

[Victor]

"My plan was to use a charge sensor, (Possible as simple as an analog amp meter with a set of contacts) to run a small computer fan to exhaust the gasses when charging over a certain rate. (10 amps). "

 It will be simpler and much more relivant to use voltage to turn your vent fan on and off as gassing is voltage dependant. Many inverters have programable voltage controlled relays within them that could be utilized for this,Xantrex SW, Outback. Some of the PV controller co's have small voltage controlled boards to drive relays , also many charge controllers can be configured for this.  There are also purpose built vent fans that operate on this principle.

 I have used blue board under smaller batteries with no problems and your L-16 size batteries should probibly be OK. I don't know what the compressive load limit of the foam is though. I would make sure that the batteries are restrained from tip over, in case the foam starts to crush.

Victor

[Peppyy]

The explosive gasses batterys create is lighter than air right? The battery box is on an insulated outside wall so it would be no problem to vent them to the outside.

I thought it would be nice to have a good acess to the batterys for maintainence.

I already had the adjustable angle shelf there so I just cut a piece of 3/4" hardwood plywood for a cover. It is hinged and latches in any position. I can cover the foam with plywood but I don't think

 I don't believe the foam I have will crush, it is high density and it had truck tire tracks on it. I have learned the local lumberyard will give you the broken pieces since they can't sell them.

Is there really any need to get fancy with a fan or would a piece of say 1/2" tubing through the wall near the top of the box be enough? (Screened of corse) It is not a very tight building, Yet anyway. I don't want to let all the cold in from outside. That would be worse than leaving them out of the box.

[RobD]

Dow Blue board is made to be relatively crush proof.(It is used under foundations) The Dow gray board isn't as crush proof. I would run a 1-1/2" inch pipe out the top and a fan (you might think about an inlet of fresh air that won't let the gasses escape. I would put a one way vent near the bottom that would open when the fan is running.
One more thing is to use plastic trays under the batts to save you a big mess if one cracks and leaks.
RobD

[TERRYWGIPE]

just keep in mind that any acid leakage will eat right through that blueboard, but the stuff is a great insulator, I'd put a piece of ply or fiberboard ontop of the bottem piece of blueboard.

Terry

[DanG]

Interstate says each 6V 225ah battery is 80 pounds and 320 pounds is alot of thermal mass to have so well insulated w/ summertime temperatures. I'm sorry to comment after the foam board has been cut but I think there should be more air space around the batteries with vent provisions to help keep them cooler. Hot batteries will evaporate off more electrolyte water & cool batteries when charging makes for longer serice life - especially important when you don't know their histories.

I think I'd have an inch airgap under batteries along with an inch space inbetween cases, with insect screens over foam board vent slots to keep the weevils out; keep the cut out pieces for re-inserting for the bitter part of winter. Hard to rodent proof foam, here in Minnesota the white-footed deer mouse will nest anywhere there is a hint of warmth - I've seen foil burger wrappers shredded in their nests more then once.

Anyway very nice find - just don't over insulate them!

[Peppyy]

320 lbs. No wonder my little Aveo fely like it was glued to the road on the way home. They sure feel heavier than a bag of sacrete. These ar not interstate batterys but ones that they brought in for replacement. I wish I had written down the lables before he cleaned them all because I honestly can't remember.

I never concidered that they may build too much heat. It is no problem to duct cool air in since it is a south-east corner. There is a large covered porch on the east side of the building that I could get a "screened" pipe under, (I have lots of hardware cloth).

Perhaps I could use a fan in the summer to draw the cool air from in the building and vent it outside with a thermal switch.

[Ungrounded Lightning Rod]

Putting the fan in the intake means you're pressurizing the box.  So you'll be blowing hydrogen and acid fumes out through any cracks in it, into the surrounding area - and driving acid fumes into the foam.  Better to put the fan in the exhaust side, accepting any acid-fume exposure it gets and reducing the exposure of everything else.  (Fans can survive that pretty well.)

I'd be careful about putting a thermal switch in there:  Scenario:  cool day, overcharging.  By the time the switch cuts in there's a lot of hydrogen accumulated.  Then the switch makes a spark...

[Peppyy]

You are correct on both counts. It would be better to use a well or probe type temp sensor. My Dad suggested battery blankets for the winter which could be controled by another sensor. Would be nice to find a double throw well type t-stat that ran between 30f and 90f for a couple bucks.

Plenty of room to mount the fan on the outside blowing out, just need to build my ductwork for whatever size pipe I need. I could use a lightweight flap on the intake so it can open easily or build a hinged, counterweighted draft plate if i want to get fancy.

I still need a voltage sensor switch to turn the fan on during charging.

[tecker]

  Sulfuric acid will freeze far below 0 so with regular charging and discharging a tight box isn't a factor . A little warm air will improve charging and of coarse if the

batteries become discharged the plates will seperate when ice formes in between.

 Outside  with  a four inch pipe buried 4 to six feet adout 20' 10 out and 10 back works for my location . An interesting observation I have made is that most batteries I

have worked with charge faster and higher when the battery is heated . Another interesting point is that when you add acid to ice the temp goes up at first then drops well below 0 f .

[ghurd]

Basic, but put them on wheels if the shelf is low.

Easier access later.

G-

[Bruce S]

I agree with this!! think Plasma burst when the switch flips.

The H2 is indeed lighter than air but it is also ladden with acid fumes, which generally has it hanging right around the tops of the batts.

Would probably be best to use a circulation fan that makes use of the sensors from the charger to "pull" or causing a slight negative pressure of the surrounding air in thorugh the cracks. The fan blades being plastic will handle the acid stuff.

Great find!

Bruce