Fitting a second battery. Help required

[Jondavball]

Hi,
Is it necessary to buy a double battery tray in order to fit a second battery in my 2012 Defender, or is there a simpler, cheaper method of fitting the extra battery under the seat? Do I need to move the original or are there recommended batteries that fit in the existing gap?

Explanations on the best way to fit the second battery would be appreciated.

Regards

Jonathan

[oldyella 76]

I have recently put a second battery under the seat of my MY 12 110.
I removed the false bottom in the battery box and pop riveted a flat sheet of aluminium in place. I then rotated the battery 90 degrees (crossways) with the terminals to the rear of the box. I lengthened the earth strap to reach the negative terminal. Then I bought a fullrivers 85 amphour battery also side ways. I have used the common negative lead with a copper tag on it to connect the earths of the two batteries. Then placed a redarc isolator in the box behind the second battery. You will have to trim a little off the turned down edge of the battery box to allow the second battery to slide in.
I have also glued some 10 mm rebber sheet to the edge of the box where the pos terminal is on the cranking battery and at the underside of the cover, this is just in case the batteries move to prevent a short. Both batteries are secured with straps and theads under the box. You will need to remove the bottom plastic cover under the box (outside) and then replace it after works.
If you wish to pm me I could send you some photos.
Lindsay.

[Jondavball]

Thanks for that PM sent

[JayBoRover]

PM from me too.

[Defender Mike]

PM from me too.

Hi John,

can you email me the pics as well.

Mike :)

[n plus one]

Looks like piccies on the forum might save some PMs :angel:

[JayBoRover]

I have permission to post the photo's on the Forum as soon as I get them.:)
"Patience Grasshopper"

[n plus one]

I have permission to post the photo's on the Forum as soon as I get them.:)
"Patience Grasshopper"

Nice work Jaybo.

PS have fun at the Safari...

[JayBoRover]

Oldyella 76 sent me a couple of photo's and a write-up and sketch, and he agreed for me to post them up. I can certainly post the photo's but we'll see how I go with the sketch as it is a .pdf file and I'm only slightly less technomonologically challenged than Oldyella!:D

So, here's the two photos:
https://www.aulro.com/afvb/images/imported/2012/08/423.jpg

https://www.aulro.com/afvb/images/imported/2012/08/424.jpg

... and the .pdf sketch is hopefully attached.

Here's his write-up:

Remove battery, jack and all other gear in box.
I have placed my jack and bracket at the drivers side just behind the second row seat. The levers will also store there as I have a drawer and it keeps them out of the way.

Remove plastic cover from the bottom of the box under the vehicle.

Then remove false floor of battery box on the inside.

Get some aluminium sheet, the size of the bottom of the battery box, if you cut it in half it will be easier to get in.

Bend plate to suit bottom of box one bend only to suit the profile of the outer side of the box, which is curved. This is not that critical as the other (inner) side has a flat and the sheet can be moved. Drill holes for the rivets and for the isolator.
Rivet plate to box as shown on sketch. ( be careful of chassis rail, cables and pipes when drilling for inside rivets). The isolator will fit at the rear of the batteries.

Relocate hole for main battery drain where required.

Then remove earth cable and lengthen cable and solder lug on for aux battery terminal.
I cut the terminal off the original cable, sweated a new section of cable with a new terminal to the original one using a section of ½ inch copper pipe with the soldered lug on it for the aux battery. This I then placed some shrink wrap over the join to make it neat.

Replace earth lead.

Then trim the stiffening fold off the top of the battery box (door side)to accept the second battery, this will only need to be done to the rear of the box as there is less height at the back than at the front. This you will need to place the battery in to find out where it has to be trimmed.
Also you will need to trim the stiffener off the cover of the box at the same place. (Door side only)

Place the main battery sideways with the positive terminal to the inside of the vehicle and the negative will be on the outside . The positive will be accessible while the negative will not be as it will be under the outside edge. Place it as forward as possible.

Make two battery clamps, I used light strap bent them to the size of the battery and welded 6mm threaded rod to the ends to allow you to tighten them. They have to have the threaded ends protruding to the bottom of the box and will need to be tightened from outside at the bottom.
Drill 10mm holes in the appropriate places, through both floor plates to take threaded rods.
Place main battery in box and secure it and make sure it is as close to the front of the box as possible. I used mud guard washers and nylock nuts.
You may have to connect the negative terminal before securing battery.

You will need to relocate the positive terminal to accept the battery, but it will still go out of the same hole to the starter. I did reverse the cable on the positive fitting to allow this.
I also placed a buss bar on it to allow to power Winch/radios ect.

Put the isolater in place and secure it then attach wires to it before you place the second battery in. (You won’t be able to do it after)

Slide the second battery in from the centre, you will need to tip the battery on an angle to achieve this. At this stage the battery will probably have gone in and out a few times as you will need to measure things.
Secure second battery as the main one.
Fix the negative terminal bolt to the earth wire, I again used a copper buss bar to attach radios ect, as the system has a common earth and I used the aux battery as it was easier to attach wires to than the main battery.

I then glued 10mm rubber to the side of the box near the positive terminal of the main battery, probably 150mm square to protect from arcs and sparks and also to the top of the lid above the positive terminal of the second battery for the same purpose.

Make sure the 6mm threads do not protrude too far outside as this will prevent you from putting the plastic cover on at the bottom.

Replace the bottom cover with the 4 original fixings.

Connect the positives and all should be ok.

Aux battery is a Full River DC 85 – 12
It is a tight fit however it can be done.

Mine is a 2012 110 2.2 litre not sure if the earlier ones are the same.

I'll see if I can document mine a little more with photo's of the baseplate, etc.
Cya