Battery box or no battery box??

mjp24coho

I'm debating whether to install my battery bank in a box or not - I'd like to get some input. Here's my setup: 800 AH 24v forklift battery (to be delivered next week). I will be putting the battery bank in my detached garage ~100 feet from my offgrid weekend cabin. Inverter and charger will be next to the battery. I'm debating putting the battery in a resin yard box with a lid - if I do that I'll need to add a zephyr vent fan to vent out of the box. Other option is to do no box - but do I need to be concerned about venting the gases out of the garage? I could add a wind-powered vent to the roof if absolutely necessary (they I would prefer to not cut a hole in my metal roof). The other advantage to a box is I could insulate in the winter. My cabin is in southern utah - as low as single digits in the winter, but low 90s in the summer. If it were in a box, do i have to worry anout it getting too hot in the summer? The easiest would be no box and no vent fan, but I wasn't sure if that would be safe in my enclosed garage (25'x30').

Thoughts?

Cariboocoot

Re: Battery box or no battery box??

Batteries do not actually give off a huge volume of gas. Putting them in boxes (usually done to protect the battery from accidents) means whatever gas there is will be concentrated in a small area unless it is forcibly vented. The danger is less in a larger space.

So it becomes a question of how much air flows through the garage? Is it heated? Anything like hot water heater around that would be a source of combustion?

In my opinion the gas risk tends to be exaggerated, and the bigger risk is exposed battery connections and acid spills/vapour.

mike95490

Re: Battery box or no battery box??

2 reasons for a box

Physical protection of the battery & terminals

Acid mist control

I don't know how bad the forklift batteries are with acid mist, if they have decent caps, or if they are always fuming away.

Bump it once with the car, and you have a real mess. Or get a conductor across the terminals......

BB.

Re: Battery box or no battery box??

In some cases, you can better manage temperature extremes (keep a battery warm(er) in winter, etc.). Depends on your needs.

-Bill

Photowhit

Re: Battery box or no battery box??

I wouldn't worry about the out gassing, hydrogen will find it's way out and you have a large area. You might build a wooden top to go around your metal box that holds your cells, that would prevent any accidental shorting, though with a 24 volt battery most likely you will have terminals over 24 inches apart or if you have a cable coming off, very little area to short anything out on.

I'd put it as far 'out of the way' as I could. though you'd have to be moving pretty good even tip over a wide base one, mine has a 13" base the narrowest, and using a 12' 4x4 I had a hard time moving it, though I did try to keep my contact low, a trucks bed that hit it near the top might have a chance to tip it over, but would have to be moving pretty good. Some of the smaller 24v have an 11" width, those might be lighter and easier to tip...

mjp24coho

Re: Battery box or no battery box??

Thanks - all good things to consider. I'm going to have water miser caps on the battery, and the battery will be out of the way (very far right back corner). The garage isn't used much - mostly for storage - and no car is kept in the garage. I'm less concerned about safety and more concerned about gassing and keeping the battery warm in the winter. Maybe I could wrap it with 2" styrofoam in the winter (except the top)?

vtmaps

Re: Battery box or no battery box??

mjp24coho wrote: »

Thanks - all good things to consider. I'm going to have water miser caps on the battery, and the battery will be out of the way (very far right back corner). The garage isn't used much - mostly for storage - and no car is kept in the garage. I'm less concerned about safety and more concerned about gassing and keeping the battery warm in the winter. Maybe I could wrap it with 2" styrofoam in the winter (except the top)?

Sounds a lot like my setup... I built a plywood box for mine with a plywood top, but no gaskets or weatherstripping to seal the top. Hydrogen is hard to contain and easily escapes from the box. Build the box so that there is room on the sides to slip in rigid foam in the winter. You might want to put a layer of foam under the batteries... acid spills will react with plywood. If you make the box tall enough you can put a layer of foam above the batteries in the winter. Lay it in so it touches the foam on the sides, but don't seal it to the sides.

I use water miser caps. They are available in three heights... the taller they are the better they work. Our host only sells the mid-size caps so I bought my tall caps direct from the manufacturer.

I built my box to sit on top of two layers of cement blocks. This puts the top of my batteries at a convenient height for maintenance and makes my battery cables to the inverter about 18 inches shorter than they would otherwise be.

--vtMaps

niel

Re: Battery box or no battery box??

if the battery sits directly on a concrete floor it will lose its heat regardless if you insulate the top and sides. maybe place it onto some wood such as plywood. if you still want the styrofoam then construct an open box arrangement giving an inch or 2 of room on the sides and even more on the depth and you can opt to leave the top off of it too, but that leaves possible accidents from shorts that can occur with dropping metal things onto it. maybe a loose top can work for you in this case.

Photowhit

Re: Battery box or no battery box??

Single digits isn't very cold for a battery, and just being in a covered area, my guess is it won't get much below freezing, the battery it's self will just have less capacity while cold. My Golf cart batteries, and current forklift battery live out side in small battery boxes and seem fine 9down to -10), I don't use as much electric in the winter though.

mjp24coho

Re: Battery box or no battery box??

If I go the route of putting the battery in a box with no lid, would you think there's any need to have any special venting in the garage? I assumed I would want to put a passive vent in the roof above the batteries, although I would prefer not to put a hole in the roof. Do you think that would be necessary? I just don't know much about the gases coming from the batteries. Or alternatively, maybe I'll just put a 18''x24" gable vent in the side of the garage at the top of the roof pitch for static venting (which is also right above where the batteries will be).

vtmaps

Re: Battery box or no battery box??

mjp24coho wrote: »

If I go the route of putting the battery in a box with no lid, would you think there's any need to have any special venting in the garage? I assumed I would want to put a passive vent in the roof above the batteries, although I would prefer not to put a hole in the roof. Do you think that would be necessary? I just don't know much about the gases coming from the batteries.

The gasses are hydrogen and oxygen. Hydrogen is really hard to contain. A loose lid on your box will NOT contain it, but the lid may prevent something from falling into your box. You do not need a roof vent in your garage... the volume of your garage is large, and unless the garage is hermetically sealed the hydrogen will escape before it builds up to a dangerous concentration... you would have to quickly boil your batteries dry to get enough hydrogen to cause an explosion.

--vtMaps

BB.

Re: Battery box or no battery box??

Batteries can "mist" a bit of electrolyte when charging/equalizing. Some folks are very sensitive to the smell of sulphur (rotten egg smell from acid in the electrolyte).

And if you have poor air circulation, the acid mist can damage stuff near the battery bank.

-Bill

SCharles

Re: Battery box or no battery box??

I am in no way an expert, so my answers come only from having a set of forklift batteries for roughly 20 yr. In my case, I had them set up in an "open" pantry area off my kitchen, so they were indoors. I fully intended to put in some ducts with a computer-sized fan or larger for hydrogen. I had them in the steel box they came in [for setting on forklifts and lifting them off for exhange]. The box had no top. Above them I put a removable shelf so I could prevent stuff dropping on the tops, though the terminals were all protected with the provided plastic covers. [Thinking dropped tools, etc.] So the tops of the batteries were open beneath the shelf and any gas could dissipate. I also had Hydrocaps. I never got around to putting in those vents and fan(s).

Our home is totally PV-powered. So I wanted my batteries indoors for efficiency. It can be really cold here for months. Your set-up sounds ok. The forklift batteries I had needed support, so a box was not optional. Or, something built around them to keep them from bulging at the sides due to their own weight. Don't know about yours, but a box or containment set-up of some sort is good.

The tops will collect a lot of dust, dog hair, etc., over time and be a hassle to clean. So some sort of loose covering will save you the labor of cleaning them off.

I had very little acid mist come off mine. After 14 or 15 years, I did begin to get some. I would occasionally lightly dust some baking soda in the areas I could see the condensed mist on the battery tops. Even though mine were indoors, I never saw any damage from acid in that part of the house.

I have a friend with his set of batteries in his pantry area, too. He build an open-topped plywood box around his [not forklift in his case] and draped a strip of plastic sheeting across the tops to keep out dust. He replaces that sheeting every year or so with new plastic.

If you have children around, be sure they can't get into mischief around those batteries.

mjp24coho

Re: Battery box or no battery box??

Sounds like I'll be fine without putting an extra vent in the garage - I think there's enough circulation in the garage with gable vents. I pick up the forklift battery next weekend (800 AH 24V) for the install. I'll be commissioning a new epanel with a magnum 4000 inverter and midnite classic. This is a big expansion over my existing small system, and my first time working with a battery this large. Any suggestions, tips, or watch-outs on connecting the battery? Should I expect sparking?

vtmaps

Re: Battery box or no battery box??

mjp24coho wrote: »

Should I expect sparking?

No. Because when you connect the battery all the circuit breakers will be off. After you connect the battery cables, you can flip on the breakers to the inverter, controller, DC loads, etc.

--vtMaps

BB.

Re: Battery box or no battery box??

Always wear a full face shield or goggles, acid resistant apron (or clothes that you can toss if they get acid burns). Remove jewlery and tape wrenches/tools so you cannot accidentally short the battery while bolting up connections.

And don't let a spark freak you out and short the battery--Or pull the wire back if it is a short and you spot weld the cable to a post.

Batteries are very dangerous and you should never take working on them lightly. Put a cover/shield over the batteries (or make a locked room around them) to keep random visitors/spouse/kids from dropping anything on the batteries.

-Bill

Cariboocoot

Re: Battery box or no battery box??

vtmaps wrote: »

No. Because when you connect the battery all the circuit breakers will be off. After you connect the battery cables, you can flip on the breakers to the inverter, controller, DC loads, etc.

--vtMaps

Just emphasizing the point vtMaps is making: without a "snap connection" to the inverter you will get sparks when its capacitors initially charge on connection. That's why a breaker on the inverter is such a good idea. Failing that, use a fuse for current protection and a battery switch.

mjp24coho

Re: Battery box or no battery box??

Thanks - good advice. I have the midnite epanel, which has the breakers between the inverter and battery, so I'll be sure and have the switched off. I'll also make sure and remove rings/watches and tape the wrenches. I'll have the batteries in a covered box, so that will keep the kids safe (even though they're never in the garage). Although, I wouldn't mind if the mice find a way into the battery box - it could be a good way to thin the herd.

niel

Re: Battery box or no battery box??

it may also be a good idea to have the battery bank fused or circuit breakered at the battery bank as a short across the battery wires prior to the epanel breaker will not pop the breaker.

YehoshuaAgapao

Re: Battery box or no battery box??

mjp24coho wrote: »

I'm debating whether to install my battery bank in a box or not - I'd like to get some input. Here's my setup: 800 AH 24v forklift battery (to be delivered next week). I will be putting the battery bank in my detached garage ~100 feet from my offgrid weekend cabin. Inverter and charger will be next to the battery. I'm debating putting the battery in a resin yard box with a lid - if I do that I'll need to add a zephyr vent fan to vent out of the box. Other option is to do no box - but do I need to be concerned about venting the gases out of the garage? I could add a wind-powered vent to the roof if absolutely necessary (they I would prefer to not cut a hole in my metal roof). The other advantage to a box is I could insulate in the winter. My cabin is in southern utah - as low as single digits in the winter, but low 90s in the summer. If it were in a box, do i have to worry anout it getting too hot in the summer? The easiest would be no box and no vent fan, but I wasn't sure if that would be safe in my enclosed garage (25'x30').

Thoughts?

I think it is good to have some kind of cover around the batteries. A full box or locked room is really necessary if you have kids under 6 around (6+ can be easily educated/disciplined, educable age range actually can vary between 4 and 8 ). You can vent a box passively if placed correctly and enlarged. I have overkill ventilation on my batteries for temperature control in the AZ heat. You want to vent outside if you don't want to smell the batteries while charging at gassing voltages.

YehoshuaAgapao

Re: Battery box or no battery box??

mjp24coho wrote: »

Although, I wouldn't mind if the mice find a way into the battery box - it could be a good way to thin the herd.

That is if the Mice don't chew up your wires before the die.

YehoshuaAgapao

Re: Battery box or no battery box??

BB. wrote: »

Always wear a full face shield or goggles, acid resistant apron (or clothes that you can toss if they get acid burns). Remove jewlery and tape wrenches/tools so you cannot accidentally short the battery while bolting up connections.

Just a slight rubbing of battery acid eats through cotton like it is nothing. One of jame's helpers got a big surprise hole in his jeans just from carrying the batteries after a 1-2 hour nap. Polyester is more resilient but not immune. If you drop a drip from a hydrometer onto your soccer jersey and you clean it up with baking soda water somewhat promptly it is unaffected (you can even wait until you are done and it will be fine though waiting can cause a permanent stain and polyester is stained very few things). Cotton would get eaten through within minutes. Most people wear cotton and hence the Apron advice.

Dripping from hydrometer? My battery boxes are not hydrometer friendly. The boxes are top loaded and the tops of the batteries are a little a foot below the top of the battery box. Either I have to stick my whole head into the battery box to read the hydrometer (I am nearsighted and my distance limit for reading is about 12-15 inches, about 9 inches for the small poorly contrasted print on the hydro, and glasses are uncomfortable for anything less than 5 feet) or I lift the hydrometer to read it and sometimes I just don't feel like kneeling or sitting if only checking a battery or two. The battery boxes are very friendly for wiring and watering from a chair though. I have both a EZ-Red plastic super to easy use hydrometer and a old-school Deka glass hydrometer with a temperature correction thermometer in it. The Deka drips badly when lifted out. THe EZ-Red hardly drips at all.

Think taping is a good idea, especially with forklift batteries that have terminals close each other. I dropped wrenches several times in my battery box when I was redoing the terminals because the non-stainless steel washers nearly instantly corroded (steal is galvenized with zinc and batteries eat zinc for dinner), but Surrette happens to put their terminals on the opposite corners of the batteries and I have 1.5-2 inches between batteries so it is difficult to short the terminals (wrench not long enough or it just falls). Another thing is accidentally putting your hand across a positive and a negative terminal (between batteries) can hurt a little but it don't lock anything up (probably because it is only 6V between the terminals).

YehoshuaAgapao

Re: Battery box or no battery box??

vtmaps wrote: »

mjp24coho wrote:

Should I expect sparking?

No. Because when you connect the battery all the circuit breakers will be off. After you connect the battery cables, you can flip on the breakers to the inverter, controller, DC loads, etc.

The only spark I saw/heard is flipping on the inverter breaker (The utility AC disconnect and the main house panel's main breaker can make good sparking sounds too when turning on). Sparking among the batteries? If all disconnected, only if you short something within the battery bank (wrench, etc..).

mjp24coho

Re: Battery box or no battery box??

niel wrote: »

it may also be a good idea to have the battery bank fused or circuit breakered at the battery bank as a short across the battery wires prior to the epanel breaker will not pop the breaker.

I assumed that would be necessary as well, but when I ordered the system from NAWS, they indicated it was not necessary given the circuit breaker in the epanel (5' of wiring from the epanel to the batteries).

BB.

Re: Battery box or no battery box??

mjp24coho wrote: »

I assumed that would be necessary as well, but when I ordered the system from NAWS, they indicated it was not necessary given the circuit breaker in the epanel (5' of wiring from the epanel to the batteries).

It is always a choice--I do not like double fusing--Fuses (and circuit breakers) are relatively unreliable (they have to open/"fail" to work correctly). Putting two in series is just something else to fail/debug.

However, if you like the idea of fusing near the battery (and if you ever had a battery harness short, you would think it was a good idea too)--BlueSea makes a very nice 30-300 amp fuse holder that bolts onto a terminal flag or bus bar:

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-Bill

Photowhit

Re: Battery box or no battery box??

I didn't bother with fusing my forklift battery, Most 24 volt batteries have their terminals on opposite corners of the battery some 30 inches apart and if you had yours done with cables? Just be sure to connect positive cable to the breaker first, then wait an hour or until morning and retighten, then connect the negative to the shunt and come back in an hour and check/tighten it.

Those heavy cable should make you a bit nervous, and I'll bet you check your breaker a few times before you connect it! Forklift batteries have reasonable protection from possible shorts, with very little exposed metal on top of the battery;
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tzy800413

Re: Battery box or no battery box??

Photowhit wrote: »

I didn't bother with fusing my forklift battery, Most 24 volt batteries have their terminals on opposite corners of the battery some 30 inches apart and if you had yours done with cables? Just be sure to connect positive cable to the breaker first, then wait an hour or until morning and retighten, then connect the negative to the shunt and come back in an hour and check/tighten it.

Those heavy cable should make you a bit nervous, and I'll bet you check your breaker a few times before you connect it! Forklift batteries have reasonable protection from possible shorts, with very little exposed metal on top of the battery;
Attachment not found.

I want to know does this is a lead acid battery ? it seems big and heavy .
We are manufacturing of lithium ion battery, if you want to replace a new and powerful one, maybe we can help you . Thanks , Betterman Tan

inetdog

Re: Battery box or no battery box??

tzy800413 wrote: »

I want to know does this is a lead acid battery ? it seems big and heavy .
We are manufacturing of lithium ion battery, if you want to replace a new and powerful one, maybe we can help you . Thanks , Betterman Tan

Forklift batteries are big and heavy, and they are Lead Acid. (FLA).
They are optimized for quick charging and long cycle life at the expense of high self-discharge current.
I doubt that a safe lithium ion battery system in that capacity range can be had for even four times the cost of a used forklift battery pack.
For most RE use, the weight and even the volume are not big factors. Cost, life and and capacity play a much bigger role.

2manytoyz

Re: Battery box or no battery box??

I've had a battery bank in a garage for the past 6 years. Generally, there's no off-gassing sulfur smell, and very little acid spatter. I do keep a sheet of 1/4" Lexan on top of the batteries to prevent accidental shorting. That has probably helped keep the acid spatter to a minimum.

But I have had two batteries (different times) seriously off-gas. In each case, an older battery internally shorted, and a large amount of current went thru the battery for hours. When I got home, opened the garage door, the stink was incredible. I pulled the Anderson connector to the hot battery, disconnecting it from the system. Because of the large volume inside the garage, and a 12V brushless attic fan running, probably little risk of an actual explosion.

However, I don't wish to test my theory. I moved to our present house over a year ago, and I'm still setting up the hardware. I bought an aluminum box, from a local salvage yard, and it will hold 8 golf cart batteries. It will live outside on a concrete slab I recently poured. I welded up a steel frame to hold the ~600 lbs of batteries.

The inside of the box has been coated with a bedliner type coating. Vents have been added near the top, and a 12V brushless muffin fan has been added. The box is located on the wall on the opposite side from my Alt-Power panel. I'm keeping the battery cables as short as possible.



The box sitting next to the slab, waiting for the concrete to cure.



The box now in position, hole drilled in the box, and the wall, conduit installed. A single cable was run to determine the required length.



The old battery bank hauled out of the garage... new batteries soon to be installed in the outdoor box.