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Topic: Floor reinforcing needed to support heavy AGM batteries? (Read 575 times) previous topic - next topic
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Floor reinforcing needed to support heavy AGM batteries?
2004 Rear Bath.  In a previous thread, I asked questions about replacing AGM batteries.  I have chosen Trojan L16-AGM (6v x 2).  These batteries weigh 114 pounds EACH.  They will reside under the aft-facing dinette bench, next to the original wet-cell battery tray, which is partitioned off from the rest of the storage area under the bench.

Does the floor under the batteries need to be reinforced? 

If so,, would it be sufficient to place a stiff "plate" directly on the floor (1/2" plywood, plastic, etc.) to stiffen the floor and distribute the weight?

Or, must the flooring be structurally reinforced in some manner, and if so, how would that be accomplished?

Thanks--Ted (formerly Portland, now Berkeley)


Re: Floor reinforcing needed to support heavy AGM batteries?
Reply #1
I have (4) Full River DC-250-6 AGM's under my dinette seat in a 2003 23.5 FD. These weigh 77 lbs each. I did no reinforcement and they are fine so far, Been there over a year.
2003 23.5' Front Dinette

Re: Floor reinforcing needed to support heavy AGM batteries?
Reply #2
I have (4) Full River DC-250-6 AGM's under my dinette seat in a 2003 23.5 FD. These weigh 77 lbs each. I did no reinforcement and they are fine so far, Been there over a year.

Thanks.  Very helpful.  I take it you have 500 total amps?  I assume you went with 4 vs. 2 to obtain capacity not available in 2.  Is that correct?

Ted

Re: Floor reinforcing needed to support heavy AGM batteries?
Reply #3
Right, 2 in series is 12V at 250 AMP, then 2 pair of those in parallel is 12V at 500 AMP.
2003 23.5' Front Dinette

Re: Floor reinforcing needed to support heavy AGM batteries?
Reply #4
I have 6 of the 220 AH 6v AGM's under that bench.  They are beginning year 10 there.  No problems.  Think of it this way - I weigh nearly 300 pounds, and my "footprint" is smaller than that of the batteries.  So, the load per square foot for the batteries is much less than the load per square foot for a person.  True, the load for the batteries is is one fixed spot 24/7, 365, but that load is nowhere near standard floor design loads.

Ken F in NM
'08 MB

Re: Floor reinforcing needed to support heavy AGM batteries?
Reply #5
I have 6 of the 220 AH 6v AGM's under that bench.  They are beginning year 10 there.  No problems.  Think of it this way - I weigh nearly 300 pounds, and my "footprint" is smaller than that of the batteries.  So, the load per square foot for the batteries is much less than the load per square foot for a person.  True, the load for the batteries is is one fixed spot 24/7, 365, but that load is nowhere near standard floor design loads.

Ken F in NM
Ken, what is your roof solar footprint?
Chris
Formerly: 2002 30' IB

Re: Floor reinforcing needed to support heavy AGM batteries?
Reply #6
Chris, I have the Midbath.  I have 5 AM100 panels.  The first 4 were installed by AM Solar in 2008, and are aligned longitudinally with two per side.  I added the 5th in May, 2016.  It is mounted transversely behind the escape hatch.  I had wanted a sixth, but the only place it would fit was transversely in the rear.  I (and AM Solar) was concerned about aerodynamic effects creating lift on a panel there.  There was no structure at the point where the feet would touch down.  I decided to not try it.

Ken F in NM
'08 MB

Re: Floor reinforcing needed to support heavy AGM batteries?
Reply #7
Chris, I have the Midbath.  I have 5 AM100 panels.  The first 4 were installed by AM Solar in 2008, and are aligned longitudinally with two per side.  I added the 5th in May, 2016.  It is mounted transversely behind the escape hatch.  I had wanted a sixth, but the only place it would fit was transversely in the rear.  I (and AM Solar) was concerned about aerodynamic effects creating lift on a panel there.  There was no structure at the point where the feet would touch down.  I decided to not try it.

Ken F in NM
Thanks. Quite an array. I suspect you don't lack for amps even during the winter months.
Chris
Formerly: 2002 30' IB

Re: Floor reinforcing needed to support heavy AGM batteries?
Reply #8
Well, I use a lot of electricity.  It goes into my Mac, my DVR, my TV, and my CPAP machine.  There is a lot of other stuff, mostly minor, but I drop that battery bank down to 80% overnight when boon docking.  If I shut down that stuff in the morning and I have a clear summer day, the panels will get the batteries up to 100% by 4 or 5 PM but if I am going to leave the DVR on to record something, or if the sky is partly cloudy, I run the generator for about an hour just to be safe.

Ken F in NM
'08 MB

Re: Floor reinforcing needed to support heavy AGM batteries?
Reply #9
I have 800W in 3 panels on the roof, and 2 portable panels on the ground. The 400W on the ground have a long cable so they can be located away from the coach if I’m parked in a shady spot. Some days I can fully charge my 500 A/h batteries, sometimes not. I’m a pretty heavy power user. I have 2 Bluesky 3024i Solar controllers networked to a Bluesky IPNPro remote panel for monitoring. This is on a 23.5 coach.

Even with all that I have to be careful with it.
2003 23.5' Front Dinette

Re: Floor reinforcing needed to support heavy AGM batteries?
Reply #10
As said before, the floor under the seat is strong enough for two or even three batteries,
Many have done done it without any reported failures. It's the most logical place to add batteries, in a Rear Bath, being next to the battery box.
The popular Mid Bath has a perfect spot for two extra batteries under the refrigerator.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze


Re: Floor reinforcing needed to support heavy AGM batteries?
Reply #12
I have a question about adding batteries to a 31IB. From researching the 31 it appears that the battery box is located just aft of the entry door with the refrigerator right above.

Since the 31s use an 8 ft³ refrigerator is there enough room underneath for two additional batteries?

Or do owners place additional batteries under the sofa/bed which is ahead of the entry door?
Chet in Yorktown, Virginia

Re: Floor reinforcing needed to support heavy AGM batteries?
Reply #13
I have a question about adding batteries to a 31IB. From researching the 31 it appears that the battery box is located just aft of the entry door with the refrigerator right above.

Since the 31s use an 8 ft³ refrigerator is there enough room underneath for two additional batteries?

Or do owners place additional batteries under the sofa/bed which is ahead of the entry door?

I suppose you could remove the two drawers beneath the frig and put two or maybe more in there if they are AGM or lithium. I know of one person who installed some in the storage space under the couch that you access from inside next to the steps.

However, if you are planning on full timing there is the weight to consider with lead acid and the loss of the space. We don't have additional batteries or hydraulic levelers because of weight. However, we usually spend months boondocking each year and with our two Trojan T-145s and 360 watts of solar have never run the batteries below 50%. Our first Trojans T105 were replaced in January 2014 at over 7 years use and still seemed to be working OK at the time.

Of course, we camp almost always in wide open spaces.

Jim

Re: Floor reinforcing needed to support heavy AGM batteries?
Reply #14
Oh, very good point regarding the drawers beneath the refrigerator - I would not want to goof with those. It seems under the couch would be ideal and I believe I remembered reading of others placing additional batteries there. From what I understand most folks add two additional batteries?

Regarding the additional weight I am pretty sure I will be just fine. I do understand things will add up but I am a minimalist at heart and will not be carrying much. As we know, the total weight overall is not a binary good/bad or pass/fail type of event. There is a fair Factor of Safety engineered in to everything so on my end I simply must respect the fact that the vehicle is outside of those design parameters and drive accordingly.

I guess what I really need to do is to estimate my daily energy use and design a solar system around that. I am not a heavy user of energy but then again I have no desire to spend my time worrying about only using this for so many minutes or turning everything off all the time. And then there must be some ideal ratio for solar panel capacity to battery storage. Maybe one 100 W panel per battery is good for most situations whereas two 100 W panels per battery would work for most of the more extreme conditions?

Lots to learn so any additional suggestions are always welcome :)
Chet in Yorktown, Virginia

Re: Floor reinforcing needed to support heavy AGM batteries?
Reply #15
From what I understand most folks add two additional batteries?

Yes, hard to get 12 volts from three 6-volt batteries.  ;) 
Greg & Victoria
2017 Mid-Bath  “Nocona” towing a manual 2015 Forester
Previously a 1985 TK
SKP #61264

Re: Floor reinforcing needed to support heavy AGM batteries?
Reply #16
"I guess what I really need to do is to estimate my daily energy use and design a solar system around that."
----
And, I believe that it's a good idea to plan a system that allows for upgrading and expanding; neither technology nor one's power needs are likely to remain static.  ;) 

The information at this link may be helpful!

Solar Panel DIY Installation Help & RV Solar Power Setup | AM Solar
2003 TK has a new home

Re: Floor reinforcing needed to support heavy AGM batteries?
Reply #17
"Lots to learn so any additional suggestions are always welcome :)"

Me thinks you're in the ball park with one panel per battery. I have 3 100w panels feeding 2 AGM batteries and with moderate usage my batteries never go below 50% at any time.   ;D
Steve S.
Lazy Bones & Cedar
2004 30'IB (Island Bed)
Yesterday is History, Tomorrow is a Mystery
Live for the day!

Re: Floor reinforcing needed to support heavy AGM batteries?
Reply #18
""Lots to learn so any additional suggestions are always welcome :)"

Me thinks you're in the ball park with one panel per battery. I have 3 100w panels feeding 2 AGM batteries and with moderate usage my batteries never go below 50% at any time.   ;D "

•~•~•~•~•~•~•~•~•~•~•~•~•

We do fairly well with four 100-watt panels and four 220-amp AGM batteries, but there are two of us.  A bit of generator pumping is frequently necessary to keep things ramped up to 100%, but that is (again) for TWO people, who both use computers.  We don't use electrical appliances (except the water pik) when we are not hooked up to a power pole, and that includes the microwave.  Lighting has been upgraded to less power usage fixtures, so I'm not clear where all the energy disappears to, but it does.

I seem to be fascinated with the two "power storage" devices that I am seeing now, i.e. Goal Zero.

GOAL ZERO Yeti 400 Solar Generator Power Pack 23000 B&H Photo

Coupled with a some solar panels, one could do device charging (or use for CPAP) from such an item while not impacting the built-in charging to the coach's battery system.  Useful if roof real estate is insufficient to accommodate sufficient solar panels to keep the main coach battery at a useful level, or because of inclement weather.

   Virtual hugs,

   Judie  <-- Sierra Vista, Arizona
   Adventures of Dorrie Anne | Photographing the West

   Today:  Swirls, not Seeds
   ***************************
 
 

Re: Floor reinforcing needed to support heavy AGM batteries?
Reply #19
I would wait until the new 31’ model is fully outfitted and used for a long trip or two before weighing it and seeing how much excess CCC you have.
Make sure to include full water and fuel tanks when weighting. It can be tempting to travel with a near empty water tank, assuming water will always be available, but this can and has backfired more than a few times. I learned the hard way.
It can be very difficult not to use the abundant storage area and overload a 31’er.
Look into installing lithium batteries for increased storage capacity with less weight.
RV Solar Panel Kits & Camping Solar Panels, Batteries & Chargers: AM

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze

 
Re: Floor reinforcing needed to support heavy AGM batteries?
Reply #20

"And, I believe that it's a good idea to plan a system that allows for upgrading and expanding; neither
technology nor one's power needs are likely to remain static. ;) "

•~•~•~•~•~•~•~•~•~•~•~•~•


Each participant in this wonderful world of RV'ing will have different needs, but being able to assess those needs, following through with the appropriate installation, and enjoying the ride, sometimes results in a bit of a bumpy adventure due to unforeseen circumstances.

One lesson we learned when relying on solar accumulation for our power needs was understanding the circumstances under which it just wasn't going to be suitable.  This is usually a temporary situation.

If running a generator is anathema to you, then just don't do it.  As one gains experience, it becomes clear what is needed for suitable participation in this endeavour.  I read here that many folks do just fine with two, or even one, solar panel installed by the factory.  Others find that covering every available inch of the roof is not sufficient.

The cost, weight, and space consumption of a power system that is sufficient at all times is probably elusive, and variable from rig to rig.  Some folks require more power than others.  There are so many factors at work here that each individual's needs and solution will be different.

For ourselves, we have been content to use our four-panel, 400-watt rooftop power supply with occasional use of the generator.  If the generator were not available, or its use forbidden, I would just cut back on usage and/or go to a campground where there is an electrical pedestal for a night, and "fill 'er up", and then re-embark on our journey the next day.  Or stay put for a few days - whatever seems right for the moment.  To me, having this choice is what it is all about. 

Even at the high cost of campground stays these days, an overnight visit would provide a lot of value for that fee.  An occasional (or even weekly) visit to a Mom and Pop campground can provide the necessary dump station, water refill, garbage disposal, laundry facilities, and recharging of your battery system, and all of your electronics as easily, and a lot cheaper, than relying on the huge expense and weight of a personal power system that will cover your every need at every moment.  A bit of flexibility can save a lot of weight and expense.  A more thorough monitoring of the electrical power from the campground's pedestal may be necessary in a smaller campground, but if you don't want or need a "resort" atmosphere, an occasional low-cost overnight can prove quite economical.

All that said, I would definitely have a portable, back-up battery of some substance to maintain my electronics so that in the case of a power shortage that happens at an inconvenient time, I could muddle along until it was more convenient to change venues to solve the problem.  We already have an Anti-Gravity portable battery, but I have my eye on the Goal Zero units now.

Books, magazines, napping, contemplation, going for a walk - with a companion, pet, or camera - none takes any electricity - It's about choices, after all.  ;->

Virtual hugs,

Judie

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