Batteries inthe cellar ;)

lamplight · August 2007

didnt want to hijack other thread with different ?'s so:

ok so i ordered one of those toughboxes as a battery box and will be moving my batteries 14' to the basement, and into this box. this will be 6awg cable and is a maximum of 16'. since i understand inverters want to be really close to the battery terminals i suppose im going to have to mount my 600w inverter on a board next to the box, in the basement. is this what people do or should i leave the inverter on the next floor near my charge controller/panel (connected via 12-14' of wire to batts)? im not excited about exposing it to humidity (the inverter). it would be easy if i could mount it in the box but im gathering this is not a good idea.

also i plan to put in some convection venting outlets in the battery box (they are currently not in a box in a closet that does not shut tightly so no buildup of gasses, I would put vents near the top of the box that will go straight to outdoors and a hole below the height of the tops of the batts. so my ? in the other thread was about this: hydrogen is lighter than air right? so under most situations it would go up and out as i plan, however yes there will be windows or other scenarios that might make negative pressure from what i want and some gasses may come in. or worse case a scenario where no air movement occurs and buildup in the battbox of fumes which would be more concentrated then vented in an open room which does no appear too dangerous. .im thinking small battery bank, minimal gassing only certain times of certain days... it should be at least better than what i have now - yes or no?

there are appliances with pilot lights in the basement, the water heater is about 10' away from where i want to put them.

it gets somewhat humid down there in summer

Im thinking it might be better to keep them upstairs, but the current location isn't working as its to close to the power panel and id have to find another place in a already stuffed small house. is the toughbox insulated that much? i wonder how they'd do in another insulated box outside the house, that might work space and distancwise. i suspect even with alot of good insulation i'd need lots more current in winter to keep them charged

thoughts? (here we go.... :roll:)

Thanks!

niel · August 2007

Re: Batteries inthe cellar

matt,
you know sometimes there just isn't any easy answers for whatifs can always happen and there's a detriment to any location. i really don't remember how many batteries you have, but i don't think it was very many if memory serves me right. i'd have to agree that the basement looks like it would be more detrimental than upstairs, but where to put them is a perplexing problem you must solve. it's hard to say what should be moved to accomodate them or where. yes a box could concentrate the gasses and a defective battery causing a spark is a remote possibility. the odds on you opening the box and something falling to the posts causing a short even temporarily is much more of a real possibility than the first scenario.
btw, you are right to keep the inverter out of the box and i'll go one further and say no fuses or breakers in there too. yes, they need to be at the battery, but can be just before the wires enter the box. the chances of the gasses igniting from a fuse or breaker are too great imho to warrant it being inside. even a faulty exhaust fan for those gasses could be detrimental if they become faulty and fans do fail with great frequency.
what would i do? what i'd do may not be right or what everyone would do. i probably would seal the box air tight for only a few batteries. i would not vent them anywhere as hydrogen production would be minimal and if it should occur it would be confined in the b box with a lesser chance of ignition than if allowed to go anywhere else whether accidentally or on purpose. larger banks have to have provisions to get rid of the gasses as the explosive potential would become too great. as i had said whatif can always happen. you just have to figure out what minimizes your risks and at what costs are you willing to go to get it done. longer distances to the batteries do mean an increase in the size of your wires to overcome losses too. you must weigh all of the pros and cons for your system considering safety first and costs secondary. a sealed box vented outside (no fans)could also have some whatif scenarios, but is still a good option. the detriment to that would be the exposure of the batteries to the colder winter air. this means your bts must go into the b box. more wires increase whatif chances too. up to you what's best.

lamplight · August 2007

Re: Batteries inthe cellar

yes, it's only 6 batts. i figured basement was midway between inside and out temp wise (actually much warmer). and i figured moderately safer to get it out of the direct living space if there was a prob.. i will do some more searching on battery box design etc.. i want to get it right before cutting holes in the toughbox and running the wires.

lamplight · September 2007

Re: Batteries inthe cellar

well, moved everything down there yesterday with no mishaps though i was nervouse undoing the batts as i hadnt touched them since 04 as far as moving. i extended the cables to the charge controller (upstairs) by about 10' and encased therm in flexible electrical conduit that i connected through the box with one of those round cable clamp opening things.. (where cables come in on a circuit box). that part is pretty close to airtight and it's just open upstairs before the cable go into the shutoff, i figure some gas output will happen there didnt want to run a closed cable right into my fused battery shutoff. then i have another hole in the box (contico toughbox: $75 on ebay delivered) with the inverter cables coming out about 4' , this also is encased in flextubing until it gets to the inverter/fuse where its open, i figure some gas will escape there as well, and thios flextubing doesnt provide an airtight connection at the box opening so there will; be seepage of fumes there too. i feel pretty good about the box and setup: water will not get in if i have a leak and it should even do pretty well if water came at it sideways. the cellar doesnt flood, and if it did its a few feet up from the lowest part (its multilevel) and the holes i drilled are yet a couple more feet up. i think i might later move the rest of my components down there too as i put a larger board up to handle the controller, etc.. later.

the only thing that concerns me is if a pipe busted (POSSIBLE, very old house) my inverter will be toast. my tentative plan so far is ti build something like a large wall cabinet with a door, but only 8" deep or so for my components and mount it all there on the wall. next to the battery box. i though probably a draped peice of plastic over the cabinet might not be a bad idea either. any other ideas for electrical components in a humid basement ? i may leave upstairs in the closet, ive yet to see how the inverter fares

oh update - for the first time since march 04 when i put these in i had the batteries unhooked at rest with no loads (trojan t-105's) and i was VERY pleased when i hooked everything back up it was resting at a healthy 12.8, must be doing my maintenance correctly

mike95490 · September 2007

Re: Batteries inthe cellar

lamplight wrote: »

build something like a large wall cabinet with a door, but only 8" deep or so for my components
i though probably a draped peice of plastic over the cabinet might not be a bad idea either.

How much heat does your inverter generate ??

lamplight · September 2007

Re: Batteries inthe cellar

well normally im running under 200w, so little heat. i was thinking a 3/4" tube to outside for this enclosed cabinet. too small or bad idea? (with a screen).

in summer i can run the ac on it sometimes and it actually overloaded due to heat once so that is a good question.

Batteries inthe cellar ;)

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