How much of an issue is battery off gassing?

[BigT]

When I was a kid, heck, before I was born, my dad had a 1963 Ford Falcon Van (I guess this was before the Econoline moniker), and it had the battery behind and slightly under the driver's seat.  Eventually he installed a larger battery that wouldn't allow fitting the cover back on the battery box, so he went without.  This "topless" system was used for another 40+ years, and I don't ever remember having a problem with it.  
Furthermore, my dad was a chain-smoker his entire life and smoked in the van every-single-day, and not once did he experience a fire or explosion from leaking hydrogen, even though he held a lit cigarette less than 4' from the exposed battery while it charged.  

If I recall correctly, our own Bob said he uses lead-acid batteries in his rig and has had no issues with it at all.  

So how serious is this off-gassing issue really??  My Transit Connect has windows on the sides that slide open, and I routinely drive with the heater/AC fan blowing.  I'm also planning to get a small, 12V fan for when the van is sitting on hot days with me in it, so cross-ventillation would be a regular thing.

My reason for asking has to do with my planned solar set-up.  It seems solar alone isn't going to be enough to keep an AGM deep cycle battery happy and healthy, at least not for long.  Since I don't want to hook the battery up to the van's alternator for additional, higher Amp, charging, I'm wondering if there's a battery design (lead-acid, something else?) I could use that would be more than happy getting it's charge solely from a 250-300 Watt panel, yet still offer the Ah needed to run a few things.  

I'm only going to be running a single battery, so it's not like I'll have 6 or 8 off-gassing batteries under my bed.   

 

[akrvbob]

Make no mistake, it is risky and there is danger. However, in my opinion charging with solar leaves so little risk it's well within my risk-tolerance.

In today's world that is petrified by fear many people have it as their goal to eliminate all risk from their life. My goal is to maximize my life and real life is full of risk and fear. Only the dead never face danger, discomfort or risk.

However, if you have any breathing issues, it can be a problem. If you aren't aware of any, you will probably be okay.
Bob

 

[SternWake]

Solar is still going to cause offgassing.
  Granted the volume will not be as much as a higher amp charging source pushing a battery at the limit of its acceptance, but just because solar gets a battery charged much slower does not eliminate offgassing.


Offgassing is necessary to fully charge a flooded battery.  If you never get the battery upto gassing voltages, you are not fully charging it.

If you can get that Northstar AGM for 150$, get it, and that big solar panel.  It will perform better for longer than a wally world group 29 in the same cycling usage.

Is it Ideal for maximum battery longevity? No, but you will still be miles ahead of most battery depleters. 

If you can adjust the absorption voltage and duration with your solar charge controller, extend the time the battery is held at ~14.46v for another 1 to 2 hours every 7 to 10 cycles or so.  This will mitigate the issue to some degree.


I applaud your seeking battery charging perfection.  It is as if you are willing to make no compromise when it comes to battery longevity.

Strangely the solution of hooking to the alternator, which could be the high amperage magic key to ultimate AGM longevity,  when in combination with Solar, is not a compromise you are willing to make.  

I am curious as to the reason of this reluctance.  It is really quite simple to accomplish and is not a bank breaker.

Are you ever going to have access to grid power?   A 25 to 40 amp charger and an extension cord could go a long way at keeping a high amp recharge rate AGM happy.  

The high amp recharge is not absolutely required every single recharge of an AGM.  But it is highly recommended that it is occasionally applied from a depleted state until the  battery itself starts limiting amperage in the 80 to 85% state of charge range.

 

[Optimistic Paranoid]

The only thing I can add to this discussion is the fact that over in the mainstream RV forums there are complaints about the amount of corrosion seen in battery compartments, presumably from battery gas.  Here is one such thread:

http://www.rvforum.net/SMF_forum/index.php?topic=17373.0

Do your own search and you can turn up others.

Also, the makers of various solar charge controller, inverters, etc.  all say to place their product as close to the batteries as possible, BUT NOT IN THE BATTERY COMPARTMENT ITSELF.

Draw your own conclusions.

Regards
John

 

[ccbreder]

I was born into the automotive business, so it's a long time. I have only witnessed two lead acid batteries explode. Both were under "fast charge" and bubbling like mad. Man with a cigar leaned over the battery for a closer look and the fumes blasted. Friends checked a battery and used a match to check the charging. You can guess. Neither exploded with shrapnel and all that, but eyes and skin were harmed. I have seen photos of a battery with the side blown apart. But never personally witnessed. Every battery compartment, frame work, I have seen has been badly corroded just from normal charging.

 

[BigT]

I applaud your seeking battery charging perfection.  It is as if you are willing to make no compromise when it comes to battery longevity.

I am curious as to the reason of this reluctance.  It is really quite simple to accomplish and is not a bank breaker.

Are you ever going to have access to grid power?   A 25 to 40 amp charger and an extension cord could go a long way at keeping a high amp recharge rate AGM happy.  

I just want the battery to be happy and last as long as possible, and I don't like abusing my components.  That's why I was hoping there was a safe alternative to AGM that would get sufficient charge from solar alone.  

As for my reasons for avoiding alternator charging: I'm trying to avoid drilling any holes in the van, for resale value, and I'm trying to keep my solar system as simple as possible, and completely separate from the vehicle so I can more easily move it from one van to another.  I like the idea of it not being "permanently" attached to the van (I'm weird that way).  Also, the stock alternator is pretty wimpy so I'd likely have to upgrade to a more powerful, more expensive alternator.
I also don't put a lot of miles on my van, so the alternator isn't going to be spinning all that much.  

Without going into a long-winded story about my life and where I fear it's headed (do to an old injury), I'm not sure how much longer I'm going to have a place to plug a 120V charger into.  Heck, I'm not even sure how much longer I'm going to be able to work!  Lugging a heavy AGM up my stairs to the outlet in my apartment is simply not an option.  That's another reason why I'm looking for something I don't have to regularly remove from the van and charge off 120V.  

So let's say I'm able to mount a tiny, 12V fan to my battery box and run a vent hose to the outside.  Is there a battery that will stay fully charged off of a solar panel alone?

 

[Canine]

Every van I've camped in has had the house batteries inside,under the bed.Likewise my little camper has the same setup.I figure they get enough air to dilute any off gassing.Course I don't go sticking a flame under the bed to look for something.

 

[SternWake]

Many vehicles already have a firewall pass through for feeding wires through.  I understand not wanting to drill through firewall, but resale value.  If done properly with a nice grommet, no one would ever know.

Wait, that wire should not be there!  2000$ off my previous offer! An alternator upgrade is likely not necessary either.  Modern ones do well at low rpm's and are well ventilated and can handle the heat they generate.

But I'll let it go, its like herding cats.

I've also had flooded batteries inside my cabinet, many years ago.  They were chronically undercharged and as such did not offgas a huge amount and only when underway, and they died quickly too.  One of them barfed Acid (exide nautilus) and it ate through the paint on the floor, and that smell was obnoxious.

When I realized how ineffective the alternator alone was at keeping them healthy, I got a charger, and when plugged in overnight, I could smell them charging, and opening the cabinet door was a sulfur smell blast, and I remember that moment every time I smell sulfur.

Hydrogen atoms are so small it is hard to actually contain them, Oxygen atoms less so.  It is the sulfuric acid mist carried along with them that is the bigger long term danger in my opinion although an explosion is certainly nothing to laugh off.  

One of my acquaintances was always having battery issues in his truck camper, and when I lifted the plywood board over his flooded battery, the wood was in horrid condition, as was his terminals, and the poor battery only had 10 awg to it from the alternator.

The  assumed still healthy 150$ Northstar-27 AGM on 325 watts of solar only, will outlast the wallyworld group29 on the same amount, and if you can hold absorption voltage longer every 7 to 10 cycles then it will last significantly longer.

Perfect, NO, but the wally world group29 is a poorly built flooded marine battery that will not like 50% discharges each and every day.  it will require equalization charges at least once a month which are time consuming and require special equipment than can get the battery to a minimum of 15.5v.

I'm done trying to herd cats.  best of luck

 

[BigT]

But I'll let it go, its like herding cats.

I completely agree that it's a great idea and very easy to install.  I've done complete, frame-off, restorations on several cars, motorcycles, and even a tractor, so it's certainly not beyond my capabilities.  I just don't know how long I'm going to own this particular van, so I'm doing as little to is as I have to.  

I bought the tiny Transit Connect as a kind of "test-bed" to try things out on/in.  It's far too small for full timing in, so I'll wait until I get a larger van or maybe a Roadtrek to "do it right".  

Don't get too frustrated.  I'm still planning to get the Northstar, I just wanted to make sure there wasn't something better before I pulled the trigger.  
I'm on my way to the solar dealer now to look at panels.  I've got about 39" of width on the roof to play with and length is unlimited.  Hopefully I can find something in the 250 - 300 Watt range that will fit.  I'm tempted to get the Grape 195 Watt panel, but only because the price, size and weight is within my acceptable limits (62" X 31" X 1.6 / 33lbs).  

These are the two panels I'm looking at.  

http://www.mlsolar.com/infinium-300-watt-72-cell-bifacial-n-type-mono-cystalline-panel/   33lbs.  

http://www.mlsolar.com/grape-solar-195w-panel-18-mono-72-solar-cells-gs-s-195/           55lbs.

 

[BigT]

The assumed still healthy 150$ Northstar-27 AGM on 325 watts of solar only, will outlast the wallyworld group29 on the same amount, and if you can hold absorption voltage longer every 7 to 10 cycles then it will last significantly longer.

Perfect, NO, but the wally world group29 is a poorly built flooded marine battery that will not like 50% discharges each and every day.  it will require equalization charges at least once a month which are time consuming and require special equipment than can get the battery to a minimum of 15.5v.

I have no intention, and never had, of buying the Malwart battery (maybe you're talking to someone else, though).   :shy:

I assume when you say "hold the absorption rate" you're talking about with a 120V plug-in charger?  I may have that option at work for a while, but ultimately I'm looking for a system that requires no "outside" help.

 

[BigT]

These are the two panels I'm looking at.  

http://www.mlsolar.com/infinium-300-watt-72-cell-bifacial-n-type-mono-cystalline-panel/   33lbs.  

Scratch that idea.  The 300W is bifacial, and I doubt very much I'll get any reflected sunlight off the roof with the panel covering it.  

The solar shop recommended this LG MONOX 305 Watt panel and said they could let me have it for $1.18 per Watt ($360).  
http://www.mlsolar.com/lg-monox-305...mm-frame-solar-module-module-efficiency-18-0/

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Oh, and to answer an earlier question: Money/cost isn't a problem, but I don't want to dump thousands of dollars into it either.  
I'm OK with $600 - $1,000 for my solar project.  That's, hopefully, including the battery and a 120V charger.

 

[akrvbob]

A pair of Trojan T 105 golf carts should be much less than that Northstar, probably last longer and will be very happy if fed from 250-300 watts of solar. Mine are very happy being behind the passenger seat. i have no corrosion and have never smelled them in any way.

My guess is these guys with all the corrosion issues are in RVs with crap controllers that are plugged into shore power a lot and are boiling them to death. That is very common!

If you are concerned about the off-gassing, you can put them in a vented box without too much issue and still save a lot of money and get more battery than AGM. Trojan RE batteries (short for Renewable Energy) are designed to be fed by solar and are much more tolerant of solar charging than AGMs that require huge voltages.
Bob

 

[BigT]

Thanks, Bob, but I've got a line on Northstar Group 27/92Ah AGM's for $150 new (66lbs).  

It looks like the Trojan's are 62lbs each and run about $148 per battery.  

A single Northstar, 300 Watt solar panel, charge controller and all the hardware will still weigh less than the two T-105's by themselves, and will take up less room.    You're probably right about the why the RV'ers are having corrosion issues in their rigs.

 

[MK7]

How about mounting a little USB 2.5w fan to push the air in that area around so that the gas wouldn't pool up....and eventually flow outside during driving or camping with doors opened.

 

[BigT]

I thought about that, but an AGM will make that unnecessary and give me more mounting/positioning options, like laying the battery on its side if that saves me more space.

 

[highdesertranger]

if you are using a fan to move hydrogen gas. you better make sure it's explosion proof. highdesertranger

 

[ccbreder]

There will not be that much hydrogen.

 

[Canine]

HDR:  "Don't use that fan!"

Hindenburg captain:  "Vat are you talking about, eees all ok"

 

[highdesertranger]

I hear you dusty. I mean how much hydrogen do you need for bad stuff to happen. lately every time I point out potential problems with peoples "great" ideas I get blown off or worse people actually get mad. I don't know maybe I should just agree with all these questionable ideas. but then I would feel partially responsible when they blow themselves up. highdesertranger

 

[Oberneldon]

Hydrogen has a very wide explosive limits from a lower 4% to 75% by volume