AGM Battery ?

[Raz]

Originally Posted by Jim Bennett

I have dealt with many hundreds of flooded lead-acid batteries, and have never seen, or heard of, one exploding.

Has anyone ever had this happen?

I have had very good luck with my flooded batteries over the years, with once a year maintenance. Keeping the charge up is the key to longevity I have found. I have never tried an AGM one yet though.

Yes, I know of two occasions where batteries exploded. In one case wearing glasses saved the individuals eyes. The second just made a mess. Unlike my tow vehicle which remains connected to the battery, I am continually connecting and disconnecting my battery. Because of parasitic loads there is often a spark. That and the other advantages made it a good choice for me. Raz

[Thomas G.]

Originally Posted by Jim Bennett

I have dealt with many hundreds of flooded lead-acid batteries, and have never seen, or heard of, one exploding.

Has anyone ever had this happen?

I have had very good luck with my flooded batteries over the years, with once a year maintenance. Keeping the charge up is the key to longevity I have found. I have never tried an AGM one yet though.

I've seen batteries explode twice. In each instance they were connected to a battery charger and had just been charged vigorously . They exploded when the charger clip was removed and sparked. Normally there is little gassing of a wet cell and no sparking at the terminals, but I can see buying an AGM if you can easily afford it.

[Francesca Knowles]

Originally Posted by Jim Bennett

I have had very good luck with my flooded batteries over the years, with once a year maintenance. Keeping the charge up is the key to longevity I have found. I have never tried an AGM one yet though.

And the key to safety is of course preventing sources of ignition from coming into contact with gases produced while charging. These second-nature type habits are easy to adopt once learned. Fear is a friend when it comes to these things!

As an interesting side note:

Another reason I probably wouldn't undertake the expense of an AGM battery for the trailer is the fact that explosions of RV-used batteries are much rarer than for those used in autos. This is perhaps due to the fact that many such incidents happen at the moment the key's turned in the ignition, causing a big power surge and resulting in the explosion. Not a potential problem with a battery on a trailer, at least unless one tries to fire up an inverter-connected microwave or something...

Francesca

[Brian B-P]

Originally Posted by P. Raz

... Unlike my tow vehicle which remains connected to the battery, I am continually connecting and disconnecting my battery. Because of parasitic loads there is often a spark...

One way to address this concern is to add a master shutoff switch between the battery and all loads. Once it is turned off, there will be no spark on disconnection or connection.

Examples:
AWW-500930 (from a racing supply company)
Marinco House Battery Master Switch (from an expensive but well-known RV supplier)

[Raz]

Originally Posted by Brian B-P

One way to address this concern is to add a master shutoff switch between the battery and all loads. Once it is turned off, there will be no spark on disconnection or connection.

Examples:
AWW-500930 (from a racing supply company)
Marinco House Battery Master Switch (from an expensive but well-known RV supplier)

Wow, now that's a serious piece of hardware. Where would you mount one of these?

[cpaharley2008]

If there is room, mount it right on the battery box top or side, they are about as big as pictured, they need to be near enough to run one battery cable to it and another back to the battery.

[Daniel A.]

If the vent line is clear there should be no reason for a battery to explode.

They produce very little H2 maintenance is the key.

I spent my working years dealing with H2 daily in large volumes.

If the vent were plugged the gas will build in the battery which is serious, H2 is light sensitive and can/will set it off.
This is why the casings are dark colored no spark is required to set it off.

[Brian B-P]

Originally Posted by P. Raz

Wow, now that's a serious piece of hardware.

The ones sold for race cars are used to completely cut off the battery from the car, so they need to handle starter motor current, which can be hundreds of amps (thus the very high intermittent rating). In any automotive application, they need to handle full charging current (thus continuous ratings over 100 amps). In a short circuit, it is preferable that a fusible link or wire melts before the switch fails (thus the thousand amp surge rating).

Originally Posted by P. Raz

Where would you mount one of these?

It could be mounted anywhere, but for ease of wiring it makes sense to put it somewhere along the wiring path from the battery's positive terminal to the loads. A cable from one terminal will go to the battery; a cable (ideally the one that connected to the battery before the switch was installed) will go from the other terminal of the switch to everything else in the trailer. If the original installation has multiple cables piled on the positive battery terminal, they can be piled on the switch terminal instead.

Motorhomes often have them in the interior, generally where the wiring from the battery (which is usually under the floor) enters the coach, and hopefully near the entrance door; a similar approach could be taken with a trailer.

The Marinco unit appears to be designed for surface mounting and can be mounted through a large hole in a panel, but the other one - which is an example of a very common style often found under the Hella brand although I don't see it in the Hella website - mounts though a small hole in a panel or bracket. As long as there is nothing open on the back side (to expose a contact and possible spark when switched), that hole could be right through the battery box.

Marinco RV Battery Management (includes 700 EasyFit™ Battery Switch better for mounting through hole in panel)

Whatever the location, I would want the switch out of the weather - if not inside the trailer, at least under a cover.

[bicklebok]

Originally Posted by Jim Bennett

I have dealt with many hundreds of flooded lead-acid batteries, and have never seen, or heard of, one exploding.

Has anyone ever had this happen?

I have had very good luck with my flooded batteries over the years, with once a year maintenance. Keeping the charge up is the key to longevity I have found. I have never tried an AGM one yet though.

I have had one blow up on me on a large industrial generator I was starting. The battery was in a closed in, but ventilated section of the generator. It must have sparked when I hit the starter button. Sounded like a bomb going off, and scared the crap out of me! Luckily the battery was enclosed inside a door on the generator or I would have been injured. Im very cautious about sparks around batteries now.

[Francesca Knowles]

Hey, Ronnie- is that you from IRV2, only now with a Scamp?

If so, inquiring minds want to know: What the heck happened to the "Man Cave"?

Francesca (remember me?)