HOW TO: Fabricate battery hold down straps and anchors

[John E Davies]

Note: This is NOT factory wiring!

The standard battery tray slots may not work if you install non-standard batteries, like my two Battle Born lithium 100 AH ones. Here are the two types of trays for an LE2 - the current version is on the right, it now has two latches since the single one has been known to fracture. This was posted by an Ollie member, I cannot recall his name. I hope he will let me repost it. Note the strap slot locations.

Materials needed:

Straps and anchors. Once source is Amazon, there are many universal strap kits of variable quality, pick one with stainless steel parts. This would be OK: ....

 

I prefer to use known high quality parts, especially in a case like this with thousands of dollars worth of new batteries at stake. Order these Raingler straps . ... https://raingler.com/products/tie-down-strap-set-of-4. ... which are available in Mil Spec (zero stretch). I bought the 120 inch version and cut them all to fit. Shorter ones might work for you, but allow at least twice the actual length since these double back on themselves. I used three and kept the fourth as a spare.

Footman loops (again, very high quality): https://raingler.com/products/footman-mount-set ...I drilled out the holes and used 1/4"x20x 3/4" stainless screws and self locking nuts. ... Stainless Philips Truss Head Screws ... These screw heads will clear the tracks if you locate and drill the holes high enough! Nuts will not clear them.

Tray spacers, inexpensive, easy to cut with a power saw, flame retardant:

How to drill large air vent holes in the SIDE of a PVC board - attach a scrap:

For my setup, I made a 1/4" spacer strip for the inside, and a 1/2" spacer strip for between the batteries. This leaves enough room for a third battery, and I preinstalled the footman loops for that one to make its installation easy. The front and back spacers were cut to fit, to make a snug fit.

Footman loop location: depends entirely on the battery type. Make sure all straps clear any cavities or openings. I chose to install one strap per battery, and also one "fail safe" strap across all of them (side to side). This way if any one strap loosens, the battery will remain secure.

FYI, my new wiring design allows the batteries to be easily removed and it also eliminates the extra length of heavy cables that can cause problems.

John Davies

Spokane WA

Edited March 25, 2021 by John E Davies

[Overland]

You have to unbolt the cables to pull out the battery tray?

 

FYI, Battleborn recommend that you don't use a temp sensor with their batteries - I've never asked why.

[John E Davies]

18 minutes ago, Overland said:

You have to unbolt the cables to pull out the battery tray?

 

FYI, Battleborn recommend that you don't use a temp sensor with their batteries - I've never asked why.

Yes, two 5/16" nuts on the side terminal posts, all connections can be accessed very easily with a full sized ratchet handle with the tray in place. Flip the cables off the posts, slide out the tray.... each battery positive post is individually fused. This will be a future thread....

The temp sensor is not required for the BB batteries, their onboard BMS takes care of any temperature compensation, I installed it so the VictronConnect app would show the temperature, so I can keep track of conditions inside the box. Using the app's Network feature, my new Victron MPPT controller also shows that info on its own solar display. The cable has two wires and a mini fuse, so it takes the place of the power-only black one that comes with the BVM-712. So, not needed at all, but very handy.

 https://www.amazon.com/Victron-Energy-Temperature-Sensor/dp/B08NHQ6TF4

John Davies'

Spokane WA

Edited March 25, 2021 by John E Davies

[Galway Girl]

Very great job again!  I'll look for the main post for the project when it arrives.
I'm starting my designs for a Lithium Upgrade so I'm drafting behind you.
Loved that you used what I assume are MBRF fuses on each lug.  Great space saving safety feature.

I can wait for the main posting but I'm curious, how did you mount those red and black through terminal studs?
Is there room on the backside of the battery enclosure to reach up and put on backing plates for the hole down bolts etc?

When I looked under the seat of the dinette (red stud side)  inside it looks like you would need to reach a hand up inside quite a ways to be where your through studs are mounted. Haven't looked under the bed side yet.

CS

Edited March 25, 2021 by Galway Girl

[John E Davies]

The terminal feed through posts are Blue Sea, they might be installed without drilling extra holes, but I bit the bullet and put two 2” access holes on the inside of the hull, which made attaching parts there super easy. Then I covered the holes with white plastic plugs. They are not noticable. I will try to get that thread going, it will be a long one, though I may break it down into smaller ones.

John Davies

Spokane WA

[Geronimo John]

JD:
Once again "hitch hiking" off your concepts.  

I have three Battleborns installed.  I have installed two fore/aft straps using tray slots and hooks for the straps.   

I want to add one or two straps in the port/starboard direction(s), as this owner's are showing.... but do not want to have to remove the batteries and/or tray to do so.

With three Battleborns, they tray is pretty much full so the angle of my to be installed strap would be pretty much vertical vs. 45 degrees or so as shown in pic below.

  

I am thinking of just running a strap under the tray back ,and up the back side of the back BB, and back to tray latch end to the buckle.  

This would save a lot of time and be easy and quite secure as well.  Any downsides?

GJ