Maintenance Free battery - Blew the caps off?

ken white wrote:

thestoloffs wrote:

I have a factory-supplied parallel dual 12 VDC battery system for my house batteries (including a wheelchair lift), and it's blown out one battery this year.

In this wiring system, both positive leads are on the positive terminal of one battery; the single negative lead is on the negative terminal of the other battery; and there are both positive and negative jumpers between the two batteries (i.e., a parallel installation).

How do you suggest I fuse these? Can you provide a diagram of how these batteries should be fused?

Thanks!

The fuse is inserted in the jumper wire between the 2 batteries.

Ken:

I assume that the fuse is inserted into the POSITIVE jumper, not the NEGATIVE jumper. Correct?

Any suggestions on the size of the fuse and style of the fuse holder? (I'm trying to design for ease of maintenance; the "wheelchair lift" notation should give you a hint to the reason why.)

When a battery "gasses" it evolves both hydrogen AND oxygen. Inside a low cell the stoicheiometric composition of gasses does not involve dilution via nitrogen. The hydrogen and oxygen have purged it out the cell. What you are left with is hydrogen and oxygen, uncommonly rich composition. Sometimes an occluded vent will allow a tiny percentage of pressure to build.

You have a fuel air explosive device. Moving and turbulent gasses can create static electricity. nothing on the face of the earth ignites faster than hydrogen plus oxygen.

thestoloffs wrote:

Matt_Colie wrote:
Battery explosions are kind of common with unfused paralleled batteries.

Matt:

I have a factory-supplied parallel dual 12 VDC battery system for my house batteries (including a wheelchair lift), and it's blown out one battery this year.

In this wiring system, both positive leads are on the positive terminal of one battery; the single negative lead is on the negative terminal of the other battery; and there are both positive and negative jumpers between the two batteries (i.e., a parallel installation).

How do you suggest I fuse these? Can you provide a diagram of how these batteries should be fused?

Thanks!

The fuse is inserted in the jumper wire between the 2 batteries.

Matt_Colie wrote:
Battery explosions are kind of common with unfused paralleled batteries.

Matt:

I have a factory-supplied parallel dual 12 VDC battery system for my house batteries (including a wheelchair lift), and it's blown out one battery this year.

In this wiring system, both positive leads are on the positive terminal of one battery; the single negative lead is on the negative terminal of the other battery; and there are both positive and negative jumpers between the two batteries (i.e., a parallel installation).

How do you suggest I fuse these? Can you provide a diagram of how these batteries should be fused?

Thanks!

MEXICOWANDERER,You are right on target.

I did not do a deep enough investigation when I purchased the batteries. They are definitely the batteries you describe. The batteries Winnebago put in original equipment were also Marine/RV Deep cycle, so I just replaced the same type with a different brand. I was told by the dealer they were maintenance free. I never checked fluid levels in the 6 years before I replaced with the Costco batteries. (I didn't think the caps came off.) The only difference is that I replaced the original converter/charger with the 4 stage Progressive Dynamics 6 months ago and always had the rig plugged in since then. I had never left it plugged in between trips before with the old converter. I made the change because of the claim that it would not damage the battery if left plugged in full time.

Today I pried the tops off the second battery and all cells are full. No way to check the damaged battery. Not only did the caps blow off, but the case split as well. It certainly had fluid in it when it blew, it was everywhere in the battery compartment. So, I don't know if it was fluid level or not that caused the damage.

I got the battery compartment neutralized, stripped, and re-painted over the last two days. Chassis battery and non-damaged battery put in so I have power to winterize, change engine and generator oil and prepare for winter. Monitored voltage at the Progressive Dynamics output periodically all day and it is operating normally.

No room for 6V so I will decide over winter on AGM or a set of Trojan Deep Cycle in the spring.

And yes, I will now be adding battery fluid level checks to my periodic maintenance list.

This has been very educational to me. Thanks to all that participated.

Wayne

The only "sealed" maintenance-free battery COSTCO ever sold was the old DELCO VOYAGER black battery with the evil red eye.

What you have are Johnson Controls LOW MAINTENANCE batteries with FLUSH caps. One cap per three cells. "Low Maintenance" is a buzz word. The caps are designed to be removed. Look down into the crack between the case and the caps and you will see TANGS where a screwdriver is used to pop the caps up and off and water the batteries occasionally.

These are specifically NOT calcium/calcium flooded lead acid batteries that are sealed like the old Delco Voyager was. The manufacturer expects owners to check and add water as needed. You were fooled by the flush fit of the caps to the battery case.

Plugged vent passage (dead bug?). see how the battery tests out... Take precautions before testing though.

RJsfishin wrote:
It was determined long ago, there is no such thing as true deep cycle.
Any battery that is designed to serve in deep cycle use, "IS" a deep cycle battery, like it or not.
This in not saying there is not good better and best in deep cycle batteries.

There are lots of batteries marked "marine" or similar that are marketed to the unsuspecting public as deep cycle. If they have CCA listed, I don't consider them to be deep cycle. I used the OPs term of "true deep cycle" to refer to a battery designed and intended for deep cycle use, not for combo or dual deep cycle and SLI use.

While I agree that there are a wide range of deep cycle batteries of different quality, if it's marketed for both starting and deep cycle use and it's marked with a CCA cold cranking amps rating, I don't consider it to be a true deep cycle battery.

The most common source of battery explosions is from a fractured bus bar in the hydrogen rich environment above the internal plates. The bus bar can crack and cause the arc which ignites the hydrogen/oxygen mixture. The top covers of batteries are made with reliefs for the possibility of an explosion.
MM49

It was determined long ago, there is no such thing as true deep cycle.
Any battery that is designed to serve in deep cycle use, "IS" a deep cycle battery, like it or not.
This in not saying there is not good better and best in deep cycle batteries.

The chart is a joke. Take the best battery there and run it 1/4 that many cycles, its still going to die in 10 yrs. In my experience, time has more to do w/ dying batteries than do cycles