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Double Battery Bay: Diy Installation


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I have a 2013MY Lunar Stellar and as part of a new energy system installation I need to fit a double battery box. BCA produce one but it requires a new 'flush mounted' door assembly and, of course, this is not the same size as the one I currently have. I will need to cut a slightly bigger aperture to fit this new assembly.

 

I was going to have the work done at my local dealer but it's going to be two weeks before they can fit me in and, frankly, I don't want to wait that long so I'd like to try doing it myself.

 

Any 'gotchas' to be careful of?

 

My initial thoughts on how best to approach this are:

  • Measure twice, cut once
  • Mark up the aperture and use a jigsaw with a fine metal blade to cut round it
  • Remove 25mm insulation and fit 25mm timber around the aperture to screw the battery box into*
  • Use stainless steel screws coated in sealant to secure
  • Use mastic flexible sealant on the inside, Sikaflex adhesive sealant around the external outside edge
  • Secure the rear of the battery box to a wooden baton, in turn secured to the floor
  • Swap the key barrel over from my current battery box

*how would I secure the timber inside the wall?

 

Any advice / guidance would be very much appreciated.

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If the rear of the Battery Box is into a locker, would it not be easier to fit one battery behind the other and simply enlarge the battery box within the caravan?

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lobydosser. The existing battery box would have to go. A new locker frame and door would be needed and a new battery box would have to be constructed. The Mains hook up connector would have to be re-installed. This would be a fairly complex DIY job. I think a separate sealed battery compartment in the locker box with ventilation down wards through the floor would be a much simpler and cost effective way to do it. The leads could pass through screw grommets. These separate boxes have top access.

Caravan batteries all used to be installed this way - I remember TP2 connections for them.

Ern

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If the rear of the Battery Box is into a locker, would it not be easier to fit one battery behind the other and simply enlarge the battery box within the caravan?

 

I've put a lot of energy into this project and don't want to cut any corners now. Modifying the existing box doesn't feel right.

 

 

This would be a fairly complex DIY job. I think a separate sealed battery compartment in the locker box with ventilation down wards through the floor would be a much simpler and cost effective way to do it.

 

I did consider using the locker box 'cause I never use it, tbh, but didn't like the idea of the long connecting cables that would be required to connect the two batteries in parallel (powering a 2KW inverter requires 50mm2 cable!). I have plenty of space behind the current battery box so depthwise isn't a problem.

 

I'm more concerned about cutting more out of the caravan side wall and making sure the new battery box is secure and watertight.

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I'd guess that you'd invalidate your water ingress warranty if you do it yourself.

Why cant you just fit the secont battery in the underseat/bed locker behind the existing battery. Making sure it's properly secured, either with tie down straps or alloy angle on the battery flanges.

Wiring could go through a couple of grommets to the existing battery - you don't need to cut the existing battery box about, just drill two holes for the cables. You could then construct a box or find a suitable box (plastic bread bins are good as are plastic crates) to cover the second battery, secure it to the floor with a couple of wing nuts - just drill a hole in the floor for a vent pipe. Saves having an odd sized hatch on the side of the van and having to cut a hole in the van side and it should be easier to route 50mm cables as the two batteries will be located back to back. It won't devalue the van when you come to sell it either as it will be easier to take all the mods out ready for the next one ;)

 

Don't forget it's going to be quite hard to push the batteries in and out of the battery box with 50mm cables on them so by having the batteries paralleled together, one behind the other means you can easily get to the lugs on the inside battery, pull them off and then the outside battery will slide out of the locker pulling the two cables which should slide through the grommet holes in a straight line giving you access to disconnect the outside battery. Bending & twisting 50mm cable isn't easy, even welding cable of that size isn't all that flexible in a small space. Where are you going to locate your inverter etc. I suggest that a sketch or two and a tryout of the cable runs might be a good idea before making really big holes in the van side

Edited by matelodave

2018 S-Max Titanium 2. 0 Tdci (177. 54bhp,180ps,132kw) Powershift + 2015 Unicorn III Cadz, Ventura Marlin porch awning

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I'd guess that you'd invalidate your water ingress warranty if you do it yourself.

 

I checked with Lunar prior to me fitting my external antenna (which required a few holes through the skin) and they said that I could do whatever I wanted to the 'van and they would still honour any water ingress claim unless it was proven to be caused by the modification. If the skylight leaks, they are not going to blame improper sealing of the battery bay.

 

 

Why cant you just fit the secont battery in the underseat/bed locker behind the existing battery.

 

All good points and if I wasn't so adamant on 'doing the best job I possibly can' then all your comments are insightful and pragmatic. I'm not so keen on having a battery in the living area, especially right next to the PDU and covered with anything but a fit-for-purpose battery compartment, just doesn't feel safe to me (explosion risk, momentum in a crash). This double battery bay keeps the batteries back to back and, as I'm bolting the 50mm2 cables to the battery M8 terminals and wiring them into a DC distribution busbar on the inside, I don't plan on ever removing them again once fitted.

 

It probably makes more sense seeing it so I've attached a pic. There's no battery bay yet, though I planned the installation on how deep it is, and I haven't actually secured anything yet, just wired it up. I don't usually like showing these 'interim' stages but hey ho. ..it is what is! :)

post-63455-0-73463500-1391529224_thumb.jpg

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p. s. The bit in the middle above the solar controller isn't obvious. It's a battery protection device that automatically isolates the battery if the terminal voltage reaches a configurable threshold, I've set it to 10. 5V for now. It also allows for a battery isolation switch to be used, which I've mounted on the external PDU cover. I woke up the other week and my water pump had activated during the night and completely flattened the battery (9. 5V, eeek!). That's not going to happen again.

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12V porn :rolleyes:

An eye for an eye only ends up making the whole world blind.

Mahatma Gandhi

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