Quick Question re: Jump starting a Dead Battery

[LeeRevell]

It does seem the underhood temps these days are higher, with the tight confines and cooling system ducting. They just aren't as open and ventilated as earlier. So, I think this means our batteries don't last as long. My minivan has gone through three batteries in the six years I have had it. One battery lasted a year and a half before failing. The battery shop replaced it free, as it was covered by warranty. Still, one generally expects a good four to five years.....

 

[Canine]

The term Deep cell is widely used and accepted to describe a deep cycle battery.  It is not wrong, it is just the meaning has drifted to include batteries which really can't qualify for that classification, but are placed there anyway.

Semantics.  Not worth worrying about.


The issue of how much heat a battery accepts/absorbs from a warm engine compartment is something I have no Data on, at this point.  The ideal charging voltages change fairly drastically with temperature, so a hot battery getting 14.8v is not a happy battery.  A battery kept cool is a happy battery.


I recently took my flooded battery out of service at about 465 deep cycles, only because of the heat it was generating while charging.  In terms of it meeting my overnight needs, it was, and likely still is, capable of easily supporting them.  When i measured 118F on the bottom of the cell with the worst Specific gravity reading, it was an unignorable sign of impending failure and possibly dangerous.  I pulled it and started modifications to accept a taller battery that is perhaps/hopefully in  the 'true' deep cycle variety rather than being in the marine or pseudo deep cycle category.

Look at the difference in construction in this link:
http://www.pbase.com/mainecruising/deep_cycle_battery

How much water a flooded battery needs and how often varies greatly among batteries, how they are used, how they are recharged, and how they are constructed.

A battery will start using more and more water when it nears the end of life. My Crown and USbatteries accelerated their water usage with accumulation of deep cycles and declining capacity.

I had used Wally world batteries for a while and some of those never required water, even at the end of their life. Please do not equate this with quality construction.  Also, on a 12v battery there are 6 cells and their water usage will vary among the cells and the more cycles on the battery the more the levels will vary.

A hydrometer is the ultimate tool to see how well a wet/flooded battery is responding to the charging sources available to it.  Use of A hydrometer requires opening the cells to check specific gravity, and seeing the levels in the cells is just part of the process, and noticing increased usage of water is obvious when checking every so often.


If one has a solar controller with adjustable setpoints, one can use a hydrometer and a little curiosity and tell exactly how the particular battery is responding to  those voltage setpoints.  A happy battery is one that gets back into the 'green' every time it is recharged.

Many charging sources claim to get a battery into the green, but more voltage and more time at higher voltage was required to actually get it there.

http://www.amazon.com/OTC-4619-Professional-Battery-Hydrometer/dp/B0050SFVHO

That's a good looking hydrometer in that link. In my Amazon wish list now. I'm sure it will come in handy...

SternWake, what do you think is a good commercially available battery box for a std single marine type 12 volt? I figure it has to be ventable, and while not caring to drill a hole in the floor for a vent tube, I don't see another choice (other than AGM). Thoughts?

 

[SternWake]

I am not aware of such a battery box.  Most of them are not designed around capturing the offgasses, and sending it elsewhere through a vent tube.


I've not really researched and such products.  Perhaps some material could be used to squeeze around wires and a vent tube forming a seal.

Technically, AGMS should be vented too, it is just that they are extremely unlikely to offgas unless severely overcharged and make for a good choice for those not wanting to tackle the venting issue.

But AGM's can be a bit more petulant in the charging they receive.  They do not seem to take as well to partial state of charge cycling, which is pretty much your intended use, as you will be relying on the alternator, and it cannot top off a 80% charged battery in 30 minutes of driving.  It can merely return some, and get to perhaps the mid to high 80%'s in that time.

If you can plug in weekly and  completely recharge at a higher rate the AGM should live a respectable lifespan, but cycling it in the 75 to 90% range it will not be a happy battery.   Hard to say exactly how many cycles to expect from it when unhappy.  Too many variables.

 

[Spaceman Spiff]

That's a good looking hydrometer in that link.  In my Amazon wish list now.  I'm sure it will come in handy...

SternWake, what do you think is a good commercially available battery box for a std single marine type 12 volt?  I figure it has to be ventable, and while not caring to drill a hole in the floor for a vent tube, I don't see another choice (other than AGM).  Thoughts?

I got that hydrometer at SternWake's suggestion.  You have to develop a technique to use it, but it gives the best indication of battery charge.

There are vented commercial battery boxes out there (look at marine suppliers), but they are expensive. 
http://www.bonarplastics.com/Products/Marine/MarineBatteryBoxes.aspx
I just used a watertight plastic bin with a vent made to the outside.  Wires are run through other holes in bin (in grommets). 

Venting through floor is not going to work as the gasses given off in charging (mainly hydrogen) is lighter than air.  Vents need to be high on battery box and preferably above it.

-- Spiff

 

[Canine]

Dang but I am stupid some times, not thinking to look up the type of gasses given off. I could cut the whole bottom of the battery box open and it wouldn't vent, ha ha.

The value of the forums for the uninformed and illiterate... Just proved themselves again!

I'll have to consider what SW said about my recharging habits, as the AGM would be about twice or more the cost of the FLA and I wouldn't want to ruin one, yet I have no good place to put a FLA inside and vent it properly. How do people do it correctly? I'm not going to drill a hole in the side of the van! I don't want to try and find a place underneath, hell I can't even fit underneath to check it! Argh, why are things so, "interesting"?

 

[akrvbob]

I've lived in a vehicle with FWC batteries for 13 years and never vented them and never had anything negative come from it.
Bob

 

[ccbreder]

Bob is right. Don't over-think the battery off gassing. Don't confine the little gas that does happen, protect the area around the battery from spills, good to go.

 

[VanLifeCrisis]

only time anything happened with my batteries was while charging from the wall and the van was sealed, it would alarm my co detector(?) about 4 hours in. cracking the roof vent and the front window seem sufficient to prevent it in the future.

 

[MikeRuth]

I got that hydrometer at SternWake's suggestion.  You have to develop a technique to use it, but it gives the best indication of battery charge.

There are vented commercial battery boxes out there (look at marine suppliers), but they are expensive. 
http://www.bonarplastics.com/Products/Marine/MarineBatteryBoxes.aspx
I just used a watertight plastic bin with a vent made to the outside.  Wires are run through other holes in bin (in grommets). 

Venting through floor is not going to work as the gasses given off in charging (mainly hydrogen) is lighter than air.  Vents need to be high on battery box and preferably above it.

-- Spiff

FYI to all and I'm not arguing the point about the gasses being lighter than air, but GM has and will continue venting batteries inside the vehicle to the bottom. 
My Chevy HHR has a battery in the spare tire compartment and the vent goes down below the battery. Just something to consider. I don't know of any problems venting down like that. 

 

[MikeRuth]

If you do put FLA batteries in without an external vent I'd definitely say keep at least one window open if your stationary and charging at high rate.

good bad or indifferent When my batteries are gassing strongly you can smell it,(can you say rotten eggs) and they are mounted outside between frame rail and body.

Mike R

 

[ccbreder]

Mike, your batteries are either over charging or maybe reaching the end of their life.