Safety question about battery located under the bed

[bkahler]

Thanks All, for the advice. After looking at the rear compartment where I was hoping to place a battery or two I've come to the conclusion that there just isn't enough room for a battery box with a vent. I can get a box to fit no problem but there is no easy way to get a vent to the outside that would be higher than the box. So rather than hack things up I'll find a location up front somewhere for the battery.

Thanks,

Brad

[WineStream]

The PO of my moho added a battery box external to the coach. He bolted a framework on to the chassis under the entry steps (kinda like where batteries are on the later silver mohos). There's a single group 27 there. If it ever warms up a bit and I get up the gumption to lay on the dirt floor of my storage barn, I'll shoot some pics. I'm not sure if this would be an option on a 20'er or not.

In my trailer, I have one AGM under the bed. The original battery location was near the rear of the trailer and it actually fell out!!! going down the highway. I chose not to risk that again and bought an AGM specifically to go inside the living space. It is literally right under where my head is when sleeping. I also have an Iota charger / converter; so I feel safe that there's no issues.

[bkahler]

Originally Posted by WineStream

The PO of my moho added a battery box external to the coach. He bolted a framework on to the chassis under the entry steps (kinda like where batteries are on the later silver mohos). There's a single group 27 there. If it ever warms up a bit and I get up the gumption to lay on the dirt floor of my storage barn, I'll shoot some pics. I'm not sure if this would be an option on a 20'er or not.

Back in 2008 I ran across a Argosy 20 same year and floor plan as mine. In 20' Argosy the batteries are located front and center in the engine compartment. When you lower the front hood the batteries are staring you in the face. What the other owner did was to move the starting battery down into the right front wheel well. Seemed to be a good location. I am considering something similar for my starting battery.



I've crawled around under mine a fair amount and at the moment can't think of any place a battery could be placed. I'll take some time this weekend and look again at the underside of the chassis to see if there is some place to locate a battery.

In my trailer, I have one AGM under the bed. The original battery location was near the rear of the trailer and it actually fell out!!! going down the highway. I chose not to risk that again and bought an AGM specifically to go inside the living space. It is literally right under where my head is when sleeping. I also have an Iota charger / converter; so I feel safe that there's no issues.

Is your AGM in a special vented box or just mounted under the bed with no special precautions? My original hope was to have two coach batteries and I've come to the conclusion that there just isn't room in the back under the bed for two. However I believe AGM batteries can be laid on their side so possibly my best option is to use one AGM battery laid on its side in a box vented to the outside. Laying on it's side would provide me some room for running a vent line up hill enough to vent properly.

This is the area I have to work with. The water pump is going to be moved as is the electrical panel so there is some floor space, the main problem is vertical height. Just not enough to vent a battery standing up.



Thanks!

Brad

[rodsterinfl]

AGM is best for critical areas like inside the living area but I would still purchase a lead acid in most cases. Consider that the majority of issues come from people overfilling them when adding water. A group 24 battery from Johnson Control (Wal-Mart et al) is $89 and fully guaranteed for full replacement for 3 years and prorated to 7 or 8 years. The same size AGM is about $200 with a 1 year warranty and 3 year proration.

[barts]

Here's some interesting references on gases from batteries:

http://www.apcmedia.com/salestools/S...NQZQ_R1_EN.pdf
Stibine and arsine generation from a lead-acid cell during charging modes under a utility load-leveling duty cycle - Springer

Potential toxic gases from overcharged lead-acid cells include H2SO4 MIST,SO2,SO3,stibine,and arsine, which are all heavier than air. I guess ideally one would have a small vent leading upward and a larger one heading down to permit more toxic products to escape.

I chose to vent my custom battery box downward through the floor as that worked out more easily. My guess is that hydrogen gas would quickly escape my battery box anyway; it's riveted aluminum .
H2 simply will not accumulate in an Airstream - it will very quickly find its way out the vents or seams.

- Bart

[K4TCJ]

Originally Posted by wayneskid

"There is enough room I might be able to get two batteries back there. The Argosy 20' mh only came with one coach battery and two would be so much nicer."

Brad, when you're shopping for a battery box, you might think about going to 6v batteries, some of which are a little taller than a similar 12v. For my van I replaced the original 2 84Ah 12v AGMs (parallel wired) with 2 120Ah 6v FLAs (series wired). This increased my capacity from 164 Ah to 240 Ah. See this post:http://www.airforums.com/forums/f240...ies-91911.html

Please note, when you hook batteries in series you increase the voltage only, NOT the amps. Your new twin 6 volt system hooked in series will give you 12 volts at 120 amps.Two 12 volt Batteries hooked in parallel will give you 12 volts with 2X the amps of a single battery.

[92landyacht]

Agreed with K4TCJ. When you went to the 6V batteries you actually lost amperage. With the 12V batteries in parallel you had 168AH and with the 6V batteries in series you dropped to 120AH.

[wayneskid]

Sorry, my mistake. Of course I know that two batts in series doubles volts; parallel doubles Ah. In my post quoted by K4TCJ I stated the Ah capacity of the Trojan 6v batts as 120 Ah. This is incorrect, their capacity is rated at 240 Ah (20 Hr). So my system does have 240 Ah, a 43% improvement. This did seem apparent after just a few days of use. I will be meeting up with the Interstate again in March to install a TriMetric battery monitor and wander the west for a while. With the TriMetric, I will be able to see exactly what's going on with the house batts.