battery venting

[shadow44]

Well this seems to be a highly debated topic.

I am trying to justify what my next battery purchase will be Flooded or Gel. so many things to consider, I think I may be mired down in too many technicalities.

So why could we not take a standard flooded T105 and drill and tap the lid, connect approx 1/4" (6mm) tubing, and vent that to the out side, with a flame arrestor on the end of the vent? Now I am not talking about having the batteries under my couch, but in the basement. Its a controlled temperature, fairly open area, its way closer to my 4k trace inverter. I will need at min, 15' (3meter)X2  of cable to get to my inverter from the garage. thats a lot of feet of 04 welding cable, at over $5 a foot. not to mention there will still be loss from the length.

So from what I have gathered in my very extensive information gathering, Flooded lead acid batteries are the best bang for the buck. but we really need to keep them in the house. many people have used a computer fan in various ways to vent the batteries, but I think using  a mechanical way to vent, is problematic and possibly dangerous.

So why would a simple cheap roll of plastic tubing connected in a vertical incline, (condensation to drain back) with a simple flame arrestor attached to the end, not be a safe and cheap way to get over that problem??? Am I missing something or is it one of those things people make way harder than it needs to be??

[Vic]

Hi shadow,

1.  YES,  Flooded batteries are very,  very often the best solution for off-grid cyclic uses.
2.  Venting need not be very complex -- often passive ventilation with a natural draft works fine.  This is usually one or two vents low in your battery box,  and an upper outlet very high in that box.
3.  It is probably not a good idea to drill into any battery case,  or tap it.  This is certain to cause debris from that operation to enter the case,  and will probably float on top of the electrolyte.   These chips will probably get into your Hydrometer,  and otherwise cause heartaches.   Any warranty would almost certainly be VOIDED.  Not to mention that you are then taking on the responsibility of finding tubing that will not contaminate the electrolyte over a protracted period of time.

And so on.  Just my personal opinions.   Vic

[mahendra]

i put vents on mine although i am using agms.With the vents natural draft works great .Friend of mine also use the same technique with his flooded batteries and don't have any issues.Of course you will have to do bit of feasibility study on your basement to see the most suitable area to put the vent,hint i use an inlet vent(one that takes air in the direction the wind blows mostly ) and an out let one as well.from experience you can feel slightly warmer air coming out from the out let one even when there is no wind,i guess draft come in to play there.just to justify that it works fine.hope this helps.

[Westbranch]

you may be/are defeating the recombination technology the manufacturer built into those AGM's...  they (mostly) have a pressure release type of valve that releases excess gas , caused by over/excessive charging that produces gasses faster than the catalyst can recombine the Hydrogen and Oxygen back into water... gas being released will reduce the amount of water that goes back into solution and probably shortens the battery life.

[vtmaps]

you may be/are defeating the recombination technology the manufacturer built into those AGM's...

I think he means that he vented his battery box... he has an inlet vent and an outlet vent.

Shadow44, first of all you would have to vent each cell... that's a bunch of tubes and spark arresters.  More importantly, your batteries should be in a battery box.  Once the box is built you can probably find a way to vent it passively.

--vtMaps

[mahendra]

yes the battery box not the batteries

[shadow44]

Well I had not intended to drill the case, just the vent cap. And yes each cell would be be a lot of hose. But if you consolidate them to 1 hose per battery increase the size and consolidate down to 1 outlet,  then 1 flame arrestor should  take care of the whole thing.

Building a box is a good idea just for protection. I believe I will give the passive vent another look.

I believe I have settled on the T105-RE unless someone has had better luck with something else?