Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Safety Item - rear mounted battery.

This week a Mogtalker had his Roadster catch fire when the battery live cable chafed against the battery retaining bracket and shorted out. The fire was fortunately brought under control quickly and the damage appears from photos to be repairable, although the seat backs look a mess.
There are varying views on where a battery is best located. Under the rear panel is a traditional place to put the battery. MG put them there from a very early period. Twin sixes fit nicely either side of the propshaft and can be fitted low down, so weight distribution and CofG are both covered well. Furthermore that position keeps the battery cool - but accessibility is poor, and there is a long cable run to the engine.
On the bulkhead - the battery is set high, and on the drivers side for right hand drive. Having a weighty item high up is not good for the centre of gravity, and having a container full of acid over ones legs is not ideal. The battery also gets subject to engine heat, but is easy to get at and has short cable runs.

If your battery is in the back, you need to check the cables, to make sure there is no chafing. I did mine this morning. First pic is the new jack and lifting board. Note the sleepers under the rear wheels.



This is the right side looking forward and shows the earth cable connection to the battery.


The cable curves under the carrier and locates on the left side lower bracket. It doesn't matter really if this cable chafes, because it's to earth anyway.


I've included this one to show how hard it is to see anything from below. Obviously you can take the tool tray out and remove the alloy flap behind the nearside seat to see more.


But the camera can get where no man has gone before.........
You can see here that there are two red live cables. You can also see what I think is a master fuse, I've not yet had this apart for a look. Any short downstream of the master fuse will blow the fuse, so it's only a risk on the short length of wire between battery and fuse.
The thin wires are the adaptor for the battery conditioner, which pass through the wooden bulkhead in a grommeted hole just to the left of the wingnut. The big red cables are tied out of the way with a red cable tie, and I suspect that I did this when I fitted the neoprene liner to the ally cover plate.


You can see here the relationship between all the fittings. Note that the battery has twin terminals - two positive and two earth, so that it can fit multiple applications. Note also that the live cables cross over the car in the black wrapped cable high up. This is not the cable visible in the previous two shots, that's the handbrake cable.
Note to self: The battery needs a clean.......


This is where it sneaks inside the car. Handbrake cable at the top, live cables below. This is adjacent to the offside leaf spring front mounting. The cable then runs inside the cockpit under the offside trim panel.


It emerges here. This stud is under the dash in the top right hand corner. From here the power is fed to the fuseboxes.

Having just returned from a journey around County Down and firing on all cylinders. I read your news and have checked said item and no chaffing to report.
Phew, ownership can be stressful at times.

Nice pictures, by the way.

If, like me, you have no idea about how a car works, you're less stressed as you never imagine what can go wrong.

Thanks Dave - old camera still working well close up.......

Thanks for that Dave, very helpful. A job to do tomorrow I think. Nice jack by the way...all alloy?

Alloy yes but still surprisingly heavy. And much bigger than I expected, but very good.

What's wrong with having the battery under the bonnet, as in my 2005 4/4 and almost every other car I've owned (apart from a 1967 beetle - under the back seat - kept on shorting)...?

Paragraphs 2 & 3 in Dave's original post...

Thanks for those Dave. My, how (detailed) things have changed since the mid-70s.

But - it's not a very large battery, so can't imagine it having much effect on CofG - and (mine anyway) is an Odyssey sealed gel cell so leakage should not be an issue. The advantages of accessiblity, complete protection from corrosion (unlike rear underfloor mounting) and short cable run surely outweighs the potential disadvantages.

Also consider the proximity of the battery to the fuel tank when mounted at the rear. Not a good combination (I saw two fatal fires in Minis caused by this positioning) IMO.

Nigel

The problem with batteries at at the front you have to fit an Odyssey / DMS Redflash. Whilst my experience of 4 failures in 4 years may not be typical, the other big problem is that when these batteries fail they seem to fail completely and without warning. As they are not an off-shelf-item this can be very embarrassing. Shove one in the back and any battery from Quick-fit will do

Since moving mine to the back, my battery costs have gone down from about £160 a year to about £10 a year.

A disadvantage of the rear location is that they are a b*****r to change, but realistically you need a a new battery drive into Quick-fit and the problems is theirs..

BTW what corrosion do you mean? the only area I can think of is the battery terminals, if there is any corrosion there it won't be anything to do with the location

Brian