Deep cycle batteries driving me nuts...

[WanderLoveJosh]

So I did a search, found one post that kinda asked my question...

About venting battery banks... Only planning to do 2 6volt deep cycle batteries.. The only place I have to put these would be under our bed. That doesn't worry me, what worries me is the amount I read about venting the box because of gases and such.

I figure if I need to vent it, I will just make a hole, and run some PVC pipe through the floor of the van, and put a little piece of netting on the end to keep bugs or other creatures out.

Is this an option or does anyone have thoughts on a better idea???

thanks in advance..

 

[TMG51]

I wouldn't put a hole in the floor or in the back doors due to exhaust. I would be more concerned about exhaust than battery off gassing. Incidentally, the off gassing occurs when the batteries reach their top charge - so, during the day if you're using solar, and not while you're sleeping. However if you're concerned I would just use a computer fan on them to push air around.

 

[WanderLoveJosh]

That's a much better solution, cuz I def didn't wanna have to vent a hole... lol Thanks!

 

[ccbreder]

If you vent your battery box into the living space of your van, during normal operation, the bit of fume will be so diluted to not matter. If you plug into a 120 volt charger, I would leave a door open during a high charge. Always be sure your batteries are maintained with proper level of fluid. The hydrogen being generated is not a problem if there is no spark at the battery cell. Once out side of the battery box, the hydrogen is diluted and will not explode. Hydrogen rises, so a floor vent is not best. You may smell some sulfate type odor while charging the battery. This does bother some individuals.

 

[SternWake]

To fully charge lead acid batteries means they need to be held at absorption voltage for a certain amount of time.  Basically they will start ofgassing as soon as they approach absorption voltage, and this absorption stage/voltage should be held for 3 to 4 hours or until specific gravity maxes out.


The Hydrogen takes some sulfuric acid mist with it, which is corrosive, and will eventually soften any wood right above the gassing battery.  I am one who really can smell a charging battery from far away and find it unpleasant and irritating, and sulfuric acid mist is a known carcinogen, if breathed often enough and in high enough concentrations.

So air movement is key diring the absorption stage of charging, and the absorption stage of charging is  required to get a respectable lifespan from daily  deeply cycled batteries.

Since the hydrogen and oxygen and sulfuric acid mist rise from a charging battery, not sink, a vent through the floor will not exactly send these gasses out and below, but merely help dilute them to some degree.

How much of an issue the offgassing is is highly variable depending on the person, and the ventilation and the time spent at absorption voltage and the charge rate used to get there.  Generally a shallowly cycled battery charged slowly by solar will not offgass much, but a deeply depleted battery charged with a higher amp charging source will offgass much more in the 4 hours from ~80% charged to 100% charged.

Do not believe those that say a properly charged flooded battery will not offgass.  It has to offgass to get to 100%.  the amount can be controlled by the rate at which the battery gets to absorption voltage but the only way to ensure no offgassing occurs is to intentionally undercharge the battery, and it will sulfate and lose capacity quickly in a service where it is never returned to full charge.

How to deal with the offgassing at absorption voltage can take many forms. I wound up welding a battery box with access hatch from above and mounting house bank there, but despite the access hatch it was inconvenient enough that I did not check water levels often enough and compromised the batteries by letting them get too low.

Now I have a single AGM there, and offgassing is not a concern.

 

[phillipaaron]

My batteries are under my bed with no special venting and I haven't blown up yet.

 

[WanderLoveJosh]

Awesome, well that makes things much easier... Just ordered 200W of solar this morning from renogy, Can't wait to dive into this!

 

[WanderLoveJosh]

Also I need help with one more thing i'm  a little confused about.

I found a store near me that has 6volt golf cart batteries, i'm not sure if i'm understanding this right or not... it says they are 230AH at 20 hour rate... 230AH seems too good to be true for $119.. am i misunderstanding something???

 

[29chico]

Also I need help with one more thing i'm  a little confused about.

I found a store near me that has 6volt golf cart batteries, i'm not sure if i'm understanding this right or not... it says they are 230AH at 20 hour rate... 230AH seems too good to be true for $119.. am i misunderstanding something???

You will need two of those in series to have 12v and the rating will still be 230AH.  Then you have to remember that with lead acid batteries you should not discharge them below 50% to avoid damaging them.

So $238 for 115AH of 12v real world usable power.  Not a bad deal if you shop around.

 

[WanderLoveJosh]

So then I should be plenty fine with 200w of solar to have my dometic fridge plugged in and only be off for perhaps a few hours during the night? I haven't tested myself but I have read people say it only draws 5-6 amps? Idk if that sounds realistic or not.. I've spent a decent amount of time the last few months trying to understand battery stuff and it hurts my head every time I read something... Lol

 

[akrvbob]

Unless you uy use lots ofother power, 200 watts and 2 golf carts should work very well for you.
Bob

 

[WanderLoveJosh]

Once I started thinking about this, I realized the only other electronics we have would be laptop, cameras and phone. i'm very very slowly starting to understand batteries and electronics. lol

Thanks for all the help! I'll report back next week hopefully once everything arrives and I get it all set up!

 

[SternWake]

Once I started thinking about this, I realized the only other electronics we have would be laptop, cameras and phone. i'm very very slowly starting to understand batteries and electronics. lol

Thanks for all the help! I'll report back next week hopefully once everything arrives and I get it all set up!

My laptop computer  can consume 4 to 7 times as much electricity as my 12v compressor fridge in the same time period.  It can be, by far,  thebiggest battery consumer in my van. It has a 90 watt powerbrick.  Averages 35 to 45 watts. When laptopt battery is already full.  Nearly double that when depleted. 

My fridge is about 35watts and runs no more than 20 minutes  per hour