Weight Capacity of the Battery Tray

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deppstein
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Weight Capacity of the Battery Tray

Post by deppstein »

I'm hoping someone on the Forum might be able to help me determine if the battery tray in my 2004 Premier is sturdy enough to hold two group 31 AGm's that weigh 80 pounds each (160 lbs. total). This would be 40 lbs more than the weight of my current batteries in the tray (no issues). In preparation for an upcoming 2 and 1/2 month trip coast-to-coast starting in August, I have decided to do a battery upgrade by adding smart charging capacity (a Redarc bcdc 1240d) for the alternator and replacing my current "wet" group 31 deep cycle batteries with a pair of Fullriver dc120-12b group 31 AGM deep cycle batteries (upping my "usable" Ah from around 100 Ah to around 190 Ah). Note: I thought of going Lithium, but decided that was more work than I wanted to do since I would have to replace the PD4645 (not lithium compatible), move batteries inside and futz around with a heat jacket, etc. The Fullriver AGM's are not cheap ( $660 each), but I'm looking for max capacity, and at 120 Ah and 80% discharge ability, and these fit the bill.
Any and all opinions on this welcome...particulary from those of you who have done major mods and therefore taken a good look at things from a structural standpoint.
Thanks,
David
68camaro
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Re: Weight Capacity of the Battery Tray

Post by 68camaro »

I posted the following previously on another thread:

"I elected to replaced two 6volt 220ah batteries weighing 144 lbs total with three lithium 100ah batteries weighing 100lbs.

Not sure how much our trays could hold but I did look at getting braces welded underneath to support two more 6v batteries ....."

My 6v batteries were 72lbs each, I "guessed" one more would have been fine but not two and 6v needs to be in even numbers.

I live in VA, my lithium are in battery tray, the batteries have internal heater and so far no issues with winter usage.
2001 Concourse XL Lounge model, 6.8L Ford E350 Triton V-10 Chassis.
deppstein
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Re: Weight Capacity of the Battery Tray

Post by deppstein »

68camaro--thanks for prompt response. Really good to know that you had been carrying 144 lbs in the tray with your two 6v and did not have any issues. There is a 115 ah Fullriver agm group 31 that weighs 72 lbs, so that would put me right where you were with your two 6v...and that battery would only cost me about $425, compared to the $660 I mentioned for the 120 ah version...seems like a no-brainer...I'll go with that.
Tight Lines.
David
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Blue~Go
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Re: Weight Capacity of the Battery Tray

Post by Blue~Go »

A couple of notes:

1) I think you are talking about the forward section of the driver's side underbody storage, right? That's where my stock batteries were (1999 Concourse).

I don't know the actual weight capacity (there probably isn't one) but do you have the slide-out tray (that was in the Concourses?). I removed mine (when I moved my batteries inside back around a decade ago) and it is NOT lightweight. I didn't weigh it but I'd guess around ....30#? (It's a heavy steel tray thingie with extension slides on it.) So that might buy you peace of mind for a few more pounds - knowing that the Concourse had the stock batteries and the tray in that area.

2) If you are looking for the most amp hours in a deep cycle AGM in Group 31 form factor -- along with a quality battery - you might consider the Lifeline Group 31XT. I had three of these in my Chinook for ten years before I gave them up to try some LFP (they were definitely a little tired but not actually "done" yet... I actually shed a tear when removing them as they were loyal companions for so long and SO MANY amp hours).

They are high quality, made in the USA, you can call up and speak directly to techs (in California), and they have a great, free downloadable user manual that tells you everything you need to know (I simply followed their recommendations).

But the main reason I mention them is they are a whopping (for Group 31) 125ah apiece. (They weigh 74#.) I asked their tech fellow how they got the "extra" amp hours in the same Group 31 form factor (they also make "normal" Group 31's). They explained that each plate has an A and a B side. But so that leaves the forward "A" and the aft "B" with no companion to interact with. That's the setup for a typical Group 31 (even their standard Group 31's are like this). So what they do for the XT's is cut an extra plate in half along the A/B line, then insert the "B" slice into the forward side and the "A" slice into the aft side. Hence every plate is complete with an A/B side, and you get some extra amp hours in the same Group size battery.

BTW, they have great handles (some places still show them in the old form factor, but now they have my favorite top mounted two rope handles with plastic grips - easy to use and easy to get out of the way). The posts are typical marine posts, with the usual 3/8" positive post and 5/16" negative post.
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deppstein
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Re: Weight Capacity of the Battery Tray

Post by deppstein »

Blue! Nice to hear your clacking keys! Must have been some trip you were on! Glad to see you posting again...always helpful.
Regarding the battery compartment and tray--yes, I do have that heavy duty slide out tray that came with the Concourse (don't know why, but my Premier came with a couple of "extras" like that--cherry cabinets even). The Duracell wet cell Group 31's that I have been using for the last five years weigh 60 lbs each and I have had no issues/everything still solid. So bumping weight up to 74 lbs per battery does not feel like an issue to me (68 Camaro helped ease my mind as well with his reminder that he had been carrying 74 lbs before he went Lithium). So although I was originally focused on Fullriver agms group 31 with 120 ah capacity that weighed 82 lbs each, I backed down to the Fullriver 115 ah agm that weighed in right at 74 lbs each. But then you come along with suggestion that I can get 125ah out of Lifeline battery at same weight...hmmm.
I did go and take a good look at the Lifeline 31XT...I agree with you...well constructed, great specs. BUT...the recommended charge parameters (14.3 for absorption and 13.3 for float) are a bit too low for the preset parameters of the Redarc bcdc1240d that I am looking to get as smart alternator charging in place of the Blue Sea 7622 separator I have currently. I could address that by getting a programable b2b like the Victron Orion Tr Smart, but I really like the Redarc--its really robust and seems like best option for engine compartment install (on fender wall where the Blue Sea sits currently). Wiring will be simple that way. It also has really good reviews.
So, thanks for throwing me the Lifeline tip, but I'm going to stick with the Fullriver 115dc115-12. Seems to have comparable heavy-duty construction, better fits the charging parameters (14.7 absorption and 13.6 float) of the Redarc, similar DOD characteristics, and gets good reviews. Only thing I lose is 20 ah of capacity over a pair of batteries...but going from my current capacity of 105 ah (can't go below 50% with my current wet cells) vs. the 184 ah I can get with an occasional 80% discharge of the Fullriver AGMs has me already feeling like I've been upgraded to the honeymoon suite--with smart alternator charging to boot!
David
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Blue~Go
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Re: Weight Capacity of the Battery Tray

Post by Blue~Go »

[Edited now that I have looked through the Redarc manual]:

I just read through the Redarc manual for the bcdc1240d.

Maybe I'm missing something, but I'm curious what makes you want this charger in particular? The reason I ask is this:

1) It does not look like it has the ability for setting any of the battery charging parameters. So you are stuck with their pre-set four profiles.

2) I don't see any mention of temperature compensation (?). Without that, who really cares about the profiles because you'll be undercharging if the batteries are any colder than 77ºF (which they normally will be), and over-charging any time they are over 77ºF. So the voltage settings are somewhat meaningless.

3) I see it has an included solar controller, but that's only good to 36 volts. It looks like it's geared to portable panels, but for me, even with only two modest 100 watt portable panels in series (series because you want to have a longer wire for placement options on portable panels, and higher voltage means less voltage drop), I'm hitting 40 volts in the early morning so would fry that controller day 1.

4) It's $540. I'm just not seeing the value, since, eg. you could get a Victron Orion XS (newest, best model) and a separate, more capable MPPT 75/15 (or even larger) solar controller for less than that. These will both be basically infinitely adjustable and able to use temperature compensation. Temp comp is important now, even if you buy batteries to match their preset profile. Adjustability means you can change settings in future. They will work together on a smart network, so no problem with them not playing nice even though they are separate (though mine played nice even before I set up a smart network).

(That said, I'm not just a Victron fanboy. I used a Morningstar MPPT controller in my Chinook for 10 years -- totally adjustable charging parameters and temperature compensation. It was a great, reliable controller all that time.)

What am I missing?

BTW, I don't mean to sound negative, but knowing how much you like and use your Chinook (and drive it!) I just wanted to mention these things.

Fun to chat in a thread with you :) I hadn't visited the forum in a while and so there's lots of new stuff to read.

PS: As long as I'm already sounding like a total curmugeon, I would reconsider locating any b2b charger on the fenderwell where the original one was. Mostly because it will just get really hot, and be somewhat unnecessarily exposed to the various elements. There are other reasons, but those are the main ones.

(I put mine in the area between the back of the driver's seat and the front of the couch, but would consider other locations -- just not under the hood.)

PPS: Now I'm rambling, ha ha, but since I imagine you will be upgrading the wiring, adding fuses, etc. to that charging line, don't forget the two short leads to the chassis ground if you are going to use that as part of the negative circuit (one from the Ford battery and one from the house side somewhere). I almost forgot the Ford one (on mine that went from the start battery to the chassis in the forward corner of the engine bay/battery).
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Blue~Go
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Re: Weight Capacity of the Battery Tray

Post by Blue~Go »

PS: I just noticed this in your post:

Only thing I lose is 20 ah of capacity over a pair of batteries...but going from my current capacity of 105 ah (can't go below 50% with my current wet cells) vs. the 184 ah I can get with an occasional 80% discharge of the Fullriver AGMs has me already feeling like I've been upgraded to the honeymoon suite--with smart alternator charging to boot!

Barring anything magical about the Full Rivers, I wouldnt count on going much below 50% DOD on any AGM's. When I first bought mine, I figured well okay, so 50% DOD is best for long life; but I'll just accept a shorter lifespan and go down to say 75% DOD (so 25% SOC). More ah!

BUT, what I found is that it doesn't really matter about being willing to accept a shorter lifespan, because once you get down to around 50%, the voltage is sinking so low that things like refrigerators and other electrical items become very sad or even unwilling to work. And of course even with great wiring, there is some voltage drop so it only gets worse by the time you get to the appliance. So I only went to around 50% DOD anyway. (I had three Lifeline GPL31XT batteries, so 375 amp hours, so basically 185ah usable).

If you go with the Full Rivers, I would be very interested to know what their voltage is at 80% DOD. I don't really see how it could be much different than any other AGM, but....?

(This is probably common knowledge by now, but with LFP batteries you CAN go down to 80% DOD (20% SOC) or even lower. That's because they have a very flat voltage curve, so even at that point they are in the high 12's for voltage -- that's one of their plusses. That said I was still happily using an AGM bank up until very recently.... just only down to about 50% to keep the voltage up over 12 volts.)
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deppstein
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Re: Weight Capacity of the Battery Tray

Post by deppstein »

OK...looks like it's time to move this thread off of "Weight Capacity of Battery Tray" to something more appropriate--So will start a new topic "Batteries and Chargers" under "Electrical/Electronics."
David
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