8 cells, 280AH 3.2v 24v battery Box Needed - going into RV

[tazzytazzy]

Im semi-stealing the topic from the 280ah 3.2v 12v battery box. I've been searching, but my google-fu force isn't with me or I don't know the right terms to search for. I saw the recommended solution was a group 27 battery box, is there such a thing for 8 cells?

I'm building my first Lifepo4 battery and planning to order 8 cells of 280ah from alibaba. I have the BMS selected (ElectroDacus), cells selected, just need a box now.

This will be going inside a travel trailer. Bonus points if there's extra room for a heating pad inside the box. I have basic wood working tools, so building a basic one is possible - but it won't be pretty.

 

[HRTKD]

Whatever box you end up with needs to have enough room to contain the cells as well as the compression frame. Since you're putting the battery into an RV, the compression frame is critical to prevent stress on the cell terminals.

I haven't sized a Group 27 box, but it would seem to be too small for eight 280Ah cells.

 

[berksrunner]

Does anyone have the dimensions of these 280ah cells?

 

[berksrunner]

Found it. Sorry for the bother.

Dimensions (l*w*h):

205*174*72mm

 

[OceanStateTuning]

I haven't sized a Group 27 box, but it would seem to be too small for eight 280Ah cells.

It will fit 4

 

[Metalophile]

I built my 8S 202AH inside an inexpensive Igloo ice chest with room to spare. An 8S 280AH might also fit, but I haven't measured it out - it would be close. The handles on the sides makes it possible for one moderately strong person to move the battery without assistance. My battery is about 70 lbs. The insulation of the ice chest might also help to keep your battery above freezing temperature for charging.

 

[Suijuris]

After seeing Will's milk crate 4 cell battery, I was wondering if 8 cells would fit in the longer version, which is 13" x 19", instead of 13" x 13".

 

[MisterSandals]

which is 13" x 19"

72mm x 8 = 576mm
576mm / 25.4mm/in. = 22.67in.

So it will not fit as a straight 8S but possibly with 2 cells creatively wrapped along the sides? Compression would be complicated.

 

[Suijuris]

I was thinking of another row of 4 oriented as Will has it, or >174*2 fitting into 19". I think there would be a little over 5" x 13" for BMS, etc..

 

[Steve_S]

This is for EVE 280AH cells.

Result with Optix Clear Acrylic Top:

The BMS Wire harness goes to a QNBBM-8S Active balancer to which my Chargery BMS8T-300 is connected to, the BMS unit is external to the box. Lugs Used are Selterm Tinned Lugs with 5/16 Holes which are fine for the M6 Screws while the other end connected to the Case Posts are Selterm Tinned Lugs with 3/8" holes.

The cells are "SNUG but were pre-bound prior to installation which included putting a "Pull String" (orange string with green wrapping over the knots) on each block of 4 cells to facilitate removal if required.

More Info and Details on my "About my System" pages link in my signature.
Hope it helps, Good Luck.

 

[JMH1783]

Im semi-stealing the topic from the 280ah 3.2v 12v battery box. I've been searching, but my google-fu force isn't with me or I don't know the right terms to search for. I saw the recommended solution was a group 27 battery box, is there such a thing for 8 cells?

I'm building my first Lifepo4 battery and planning to order 8 cells of 280ah from alibaba. I have the BMS selected (ElectroDacus), cells selected, just need a box now.

This will be going inside a travel trailer. Bonus points if there's extra room for a heating pad inside the box. I have basic wood working tools, so building a basic one is possible - but it won't be pretty.

Have a look at aluminum trailer storage boxes. You can find them with either top lids or front lids. Generally they are in diamond plate if it matters. I've been considering one for my batteries. I like the idea of a metal box. Aluminum is easy enough to cut. You can get grommets to protect the wires that go through.

 

[Steve_S]

IF you decide to use a Metal Box, remember that the box HAS to be lined with a Non-Conductive material, failure to do so will lead to trouble and you can bet your bippy on it.

 

[JMH1783]

IF you decide to use a Metal Box, remember that the box HAS to be lined with a Non-Conductive material, failure to do so will lead to trouble and you can bet your bippy on it.

May I suggest non-conductive AND non-flammable too.

 

[HRTKD]

May I suggest non-conductive AND non-flammable too.

So no boxes made out of pure magnesium? LOL!

 

[JMH1783]

So no boxes made out of pure magnesium? LOL!

Sure, just keep the pool chemicals in another room.

 

[Whinny]

For a metal box I would suggest "cable gland" over grommets.....

Cable gland - Wikipedia

en.wikipedia.org

 

[Gazoo]

After seeing Will's milk crate 4 cell battery, I was wondering if 8 cells would fit in the longer version, which is 13" x 19", instead of 13" x 13".

No but they will fit in this one. It is a bit big length wise but it is the only milk crate type I could find with enough inside width to fit compressed cells using simple methods of compressing cells. It has a load capacity of 125 pounds but I would still put plywood on the bottom to make sure it doesn't flex.

 

[Steve_S]

Anyone using a Milk Crate MUST CONSIDER THE BOTTOM !
A piece of tight fitting plywood or even a single "12x12" hard floor tile should be there to protect the cell bottoms.
Just imagine if/when something pokes through the bottom and punctures the thin weak aluminium casing ?

These Hard Vinyl commercial tiles can be bought in packages and often can be bought BY THE PIECE for <$2 ea +/- at the local Hardware Supply House. Look for open boxes.

Blue Dreams: 57508 | Armstrong Flooring Commercial

Blue Dreams: 57508 is part of the Standard Excelon Imperial Texture VCT line from Armstrong Flooring - Commercial. View specs & download a sample.

www.armstrongflooring.com

 

[Gazoo]

I am more concerned with the bottom of a crate flexing and stressing the cell terminals if the crate is moved around. The tiles are nice and would prevent a puncture but they also flex. Placing plywood in the bottom of the crate is knocking down two birds with one stone and is what I intend do do if I order the larger crate. I read one of the reviews on Amazon of someone who put AGM batteries in the bottom of the crate I am interested in and it flexed. Once he added the plywood the problem was solved.

 

[Metalophile]

I use a cheap plastic ice chest, but when the lid is closed there is no ventilation. Also you have to be sure to get extra long terminals if you want to feed them through the thick walls of the ice chest.