Hi Guys,

I'm about to relocate my standard battery to the boot, but before i do this wanted to check a few details.

I will be using a similar tray like this with a strap..



I have been told that the standard battery's leak or something and they need to be vented .. if not vented then it has to be closed off otherwise they wont pass inspection on trackdays.. i take it if your boot is firewalled and seperated from rest of the car this is fine?

secondly the plan was to have a junction box in the engine bay, with old connections going into it, the negative earthed int he engine bay as standard and another positive cable from the junction box to the boot onto the battery and then another earth on the negative to the chasis in the boot.

has bonus of being able to jump the car from engine bay if needed to via the box.

would this be a perfectly ok set up? ive been told by a friend that i should have an inline fuse and a circuit breaker for peice of mind as it's a road car too. is this necessary?

also any other issues/things i need to make sure of before doing it?

cheers

Eddy

 

As regards the electrics, by all means use a DECENT junction box under the bonnet, get one with a waterproof lid if you can, but I would strongly advise against using the body as the main earth. I'd run the two cables, instead of one. And yes, I probably would introduce a circuit breaker/inline fuse close the battery +ve terminal. If not, any damage and you risk a dead short across the battery, and it will explode.

You might find what you need here: http://www.vehicle-wiring-products.e...e/homepage.php

 

cheers alcazar i'll have a look at the site.. anyone know what fuse i'll need? what does the starter take when firing up? and i guess for the lil extra work, its defo worth it for peice of mind.

how about a kill switch. is that needed?

 

The starter may be the problem. I'd approach the manufacturers, or ask Ali B who seems to know a lot about batteries/starters and their specs. I've heard stories of 400A, which is WAY more than any fuse on that site, their biggest being 250A.

 

cheers mate, i'll have a lil read up and look around, will drop ali b a pm a little later aswell

 

also anyone know anything about harmful fumes emitting from the standard battery? will i have to change it for a dry cell / gell battery? or will it be fine in the boot with back seats in etc.

 

Why don't you get a sealed battery instead, much smaller and lighter compared to the equivalent cranking standard battery.
I got one for mine, it measures approx 9 inch by 3inch by about 10 inch. Easily cranks the engine and cost less than £90 :-) the company to contact is called powervamp.

 

Out of curiosity, may I ask why you are doing this?

 

yeah plan on reversing inlet and need that space for ic pipe after intercooler is flipped mate.

ianbott: how long does the charge last on that battery mate?

 

The sealed battery charges and works as a normal battery, if you look at your battery it'll have two figures on it normally, 1 will be the power the battery can sustain for a long period of time and the other is a cold cranking power, look on the powervamp website and crossmatch your numbers to a similar battery there.
Cheers Ian.

 

Hello Bud, don't bother relocating, just get a smaller bat. Will leave you with plenty of room, is a lot neater not to mention easier to fit. There's also the weight savings:





Got mine from indgo-GT for £90.

 

What odyssey battery is that bud you have there? Cheers

 

I used a 150A fuse in mine and it didn't blow. You do loose a bit of cold cranking power from the boot... But works fine.

 

I was gonna say there is plenty of room for a battery with a reversed inlet, I have mine in the boot though, Ill take some pics if you want?

Mine is wired how you want to do it with a JB in the bay etc

 

+1 for powervamp. I'm using pvr130 in my rally car, fits nicely behind front seat, or pretty much anywhere as they're small and they can be mounted any way up too

But at autosport this year I saw some even lighter and cheaper batteries, but the manufacturer name has slipped my mind!

Power cable to starter needs to be fused close to the battery

 

Have a look at this.Hope it helps.
http://wgbuckley.com/projects/battery.html

 

Evening all, I've done my relocation today to the boot and all plumbed in, soldered beautifully etc.
Check joins in wires to see what voltage drop etc on the joins at the front and rear of the car and all spot on.
Only prob I have is the cranking is really slow and even some times it makes the alarm sound before it fires and runs then it's fine.
On the colt meter it drop to around 11v when cranking so my question is what causes such voltage drop on cranking?
I can appreciate it will drop etc with the wire lengths but is it due to the cable thickeness or do I need a battery with higher cracking Amps?

I'm using 4 gauge wire front to back.

Many thanks Chris

 

The 4awg is probably the cause of your problems. It's fine with the battery in the standard position because the run between battery and starter motor is quite short, so the volt drop is quite low. Where as trying to draw the starting current down 3 or 4m of cable is giving too much volt drop. You'll probably find the cable is getting a bit warm when you try and start the engine too (although it may not be noticeable because it's not on fir long).

Best bet is probably to run some thicker cable or a seperate run for the starter motor.

 

I used 25mm sqaured cable (similar to 4 gauge I think) and got the same problem even with a new battery.

Fully charged its better but still turns over slowly. Would like to hear if thicker cable works.

 

A decent battery and 0 gauge cable should cure your cranking problems. I installed a second battery in the boot for my audio setup linked to the front with 0 gauge cable and with the front battery disconnected there was no loss in cranking power. Its good practice to fuse both ends of the cable to isolate and reduce fire risk. I have 2 new high quality 0 gauge ANL inline fuse holders with 250A fuses if any body needs them.

p.s this threads over 3 years old

 

Think the battery in the pic was a odyssey pc680 they sell on eBay for about 86-£100 and heard lots of recommendations but they do need a special charger to keep them topped up and conditioned the recommended for this battery is the ctek mxs10 also selling for roughly £90 it all adds up.

 

Thanks, A new cable sorted it

I went from the 25mm2 cable which is about 3-4 gauge to a 0 gauge cable and now it fires nice and quickly! So for anybody else making the battery cable longer then you need 0 gauge cable to run to the boot or your car will crank embarrassingly slow! The earth cable is still 25mm2 and seems fine.

 

How much does the new cable weigh?

I'm thinking of doing something similar, but it would feel a bit silly to spend £££ on lightweight battery and then add a 5kg cable

 

Depends what cable you use. My 0 Gauge positive cable from back end of boot to starter ran along the nearside sill under the carpet is 4.21M long and weighs 1.17kg. The negative is thinner and weighs about 700g. So less then 2kg. But you could run negative straight from the battery to a ground in the boot rather then the length of the car which would take you down to about 1.25kg in total. But the wire I used is aluminium copper coated so other wires will be heavier.

But then I chopped out the old battery tray and binned so much crap in the bay that I have still saved weight.

 

cool, thanks

 

On my track car i put the battery in a fibreglass box, cost around £50
Its earthed at the terminal next to the battery



Cable is around 25mm



Broke into the cable and fitted a FIA battery isolator switch, considered a circuit breaker in line but it only protects the battery cable to the starter motor, unless you mount it in the boot, so didn't bother with it in the end.





Appreciate this isn't on a Subaru though.

 

what battery tray and tie down did you use

 

First off you're posting on a thread that is originally 10 years old and the person you are asking hasn't been on the board since 2013.

Secondly, if you look closely at the images, there is no battery tray (it just sits on the battery bracket) and the tie down is probably home made to suit using the original clamps cut down as required.






Thirdly - welcome to the forum