Griffith Battery Relocation ( again!)

[monoloco]

After another happy day freezing my off ferreting about in the passenger footwell trying to get to the fuses,relays, ecu etc, I definitely want to move the battery on my Griff. I'm sure I read a load of threads a few months back about relocating the battery on Griffs/Chims but I'm b*gg*r*d if I can find them now so looks like I'll have to start a new one!

The usual option seems to be shove it in the boot but I'm not sure this is the best solution. Firstly fitting the roof in the boot is a tight squeeze at best so loosing a chunk to the battery is going to be more trouble, secondly I'm not too keen on putting the battery right next to the fuel tank -I know there's wiring in the boot already for lights etc but they are fused and unlikely to start a fire in a rear-end shunt. Finally, having had a couple of 911's in the past I am dubious about hanging a dirty great lump of lead right out the back beyond the rear wheels!

So, I had another idea There is a load of unused space low down between the back of the seats and the bulkhead for the back axle. It's not enough to put a normal sized battery in without shoving the seat too far forward (loosing the leg room gained from moving the battery in the first place). However, I wondered about getting a pair of narrow batteries and sticking one behind each seat.

Question is what batteries to use . I know there's racing batteries but these don't have the Ah capacity and I believe they are fussy about re-charging. However, I'm told some of the modern micro-hatches run with really narrow batteries about the size of a house brick that might do the trick. I thought a pair of these, one behind eahc seat and wired in parallel would give me the oompf to start her and be OK with the standard alternator etc. Anyone any ideas?

Also, if I'm extending the battery cables that far what do we reckon on cable size? 25mm sq or will I need 35?

[spend]

Buy an MGB? sounds like their old 2 x 6V cells in series arrangement Split charging adds yet another layer of complexity, but smaller to package if that is your objective. I think an old thread proposed a small battery with a booster racing battery used for starting this way? Ask Fester I think it might have been one of his dreamy schemes so he may recall the thread

[Pasco]

Well i think its a Super idea in fact i think Mikey V was talking about the exact same conversion using the small Red racing batteries as sold by Demon Thieves

[GreenV8S]

If you're looking at racing red batteries and the like make sure you understand their deep discharge characteristics before you get your wallet out. They really don't like it, and you can't treat them like just any old lead-acid battery.

[clive f]

I`m in the process of fitting the battery in the boot on mine, agreed about the roof needing so much room, but with a 2 piece thats no longer a problem.
I have made an aluminium frame that has been fibreglassed into the boot, just behind the nearside wheel, with an fibreglass battery box bolted onto it, and an insulated lid over the top all nicely secured in place, its a safe as it can be, like most things until you have a serious shunt!

[Uncle Fester]

It was one of those ideas that I had, but never managed to sort all the problems. As such I haven’t gone ahead, but I haven’t abandoned either. One day I will find a solution.

The original intention of the design team at TVR was for the battery to be located between the chassis rails just ahead of the diff cage. Unfortunately, they discovered that they needed to fit an extra triangulation tube between the chassis rails to give the required chassis stiffness. This didn’t leave enough room to get a battery of the required size in and out.

I still feel that this is the ideal location. It’s low, near the centre of gravity and protected. It’s convenient to the main chassis rails to establish a new main earth point. I think that the original intention was to have a battery box and fuse box in a moulding under the T piece of trim with access from within the car. This creates another problem for cars fitted with a roll bar, which can obstruct the removal of the T piece. As I intend to fit a roll bar some time, this is an issue for me. All things considered, it’s a lot of work to achieve. But if quick removal of the T bar was sorted then the access to the battery and fuses would be superb.

Another part of my problem is that I don’t have mains power supply to my garage. I could move house to get a garage with a power supply, but that seems a bit drastic.

So, the solutions available seem to be.

Relocate the battery in boot, plus a two piece roof to reduce the storage problems, but you still lose boot space that I am not prepared to lose.

Fit a Red Top Racing battery in the footwell. This is a much smaller battery, but has limitations. The RT batteries are dead if you ever let it go flat. They don’t respond well to a small constant drain like the alarm and clock either. So you need to have them on a battery conditioner whenever garaged. This is the least work option, but with no power in my garage, no good for me.

Then there is trying to get an RT battery or other smaller batteries (like a pair of 6V) to fit between the chassis rails. I haven’t had my body off, so I haven’t had a chance to measure the access between the chassis rails. I was waiting until I got the chance for a measure up before I took a saw to my car, only to find there still wasn’t enough room to slip in a suitable RT.

Another option would be a battery box on the parcel shelf behind the seats. I have heard of it being done, but I think it would look so bad that I won’t do it.

As you say, you could put the batteries behind the seats. On the passenger side you are just swapping legroom by pushing the seat forward. A seat in the forward position can be more awkward to get into the car than one further back. On the driver’s side, the reduced legroom might be ok for you. But when you come to sell the car you will probably have made the car unsuitable for taller drivers. I’m tall, so it’s a not a viable idea for me. In these times it’s hard enough to sell a car without excluding a section of the market. It can also be a problem if you have a roll bar fitted, or may want to fit one.

I hadn’t heard of these compact ‘micro hatch’ batteries and must look into them.

My ECU and loom were replaced with an Emerald ECU and custom loom. It was relocated so that the ECU lives in the space above the glove box. The dash top returns to form the top of the glove box and the ECU tucks into this space. This gains about 3” of inches of legroom. The dash was also rewired, so the fuse box wiring has been tidied up too. The fuse box still lives in the same place though, but I am thinking about moving the fuse box too. It’s not enough of a legroom gain by itself for my needs, but it facilitates another idea.

What I have in mind was fabricating a removable battery box for two smaller batteries, stacked one above the other. The aim is to reduce the depth of the battery as much as possible, thereby increasing legroom as much as possible.

The intention is that the box clips into a quick release mount and comes out easily. Something like an Anderson connector plugs into it. The idea is for it all to be able to come out easily. As I don’t have power in my garage, I could have a spare battery pack on charge in the house and alternate them quickly and easily.

This will require the relocation of the fuse box. I haven’t finalised that yet. There are several other jobs in this area of the car in different stages of progress. I have to fit them together.

[eff eff]

I've been trying to find out if there is a way of using 2 Odyessy PC680MJT batteries in the recesses behind the seats
I think they would fit without loosing too much leg room. They have a metal jacket option for added impact strength and are rated at
680 cranking amps for 5 seconds
595 cranking amps for 10 seconds
525 cranking amps for 20 seconds
Short circuit current over 1800A
CCA 220
17 amp hours
25 minute reserve capacity with 25amp load
With metal jacket and automotive terminals
Length 7 1/4" Width 3 1/8" Height 7 3/8" to top of terminal
Weight 16 lbs

The reason for using two is that from what I understand one would not have enough power to start a large displacement engine. Problem is I'm an auto electrical halfwit so I have a couple of questions questions:

1 Does linking two batteries double the cranking power
2 Can a standard single alternator be used to charge them both

[eff eff]

Another couple of questions, Could the batteries be wired so that only the starter got power from both?
I think that this would give the starter 24 volts and make it spin faster, but would it cook the windings?
Forgive me if this is electrical gibberish, like I said I'm no sparks!

[DaveG]

I recently located my battery in the boot following my engine rebuild. It is located behind the driver and the Targa roof still fits ok. I could post a picture except the car is down the coast at present.
I used the existing GRP battery box with side cutout for access and supported this with another platform sitting on the contoured floor and 2 brackets bolted to the rear wheel arch. Cables run over the wheel arch, down by the door and across and under the central console. All works OK.

[Wildwood]

If its just access to the terminals to bump start thats a problem, why not add a remote anderson socket to the chassis within in the engine bay, then you can plug into that and a good earthing point somewhere, an idea I had last year that Cider Andy confirmed but never got round to it

ETA, I dont have access to the info now tho...its on the TVRCC forum!

Edited by Wildwood on Wednesday 4th February 09:19

[monoloco]

Still don't like the boot option (with or without the folding roof option) -really not keen on having the battery up against the tank and all that weight hanging out the back....

My car has been pretty extensively modified (it was previuosly owned by my late-great-mate MidnightBlue -Matt Durys). He fitted it with a Mega-Squirt ECU which entailed a lot of butchery to the wiring harness so under the dash/passenger footwell it really does look like spaghetti -hence my need to get a bit more room under there to see what the hell is going on.

As Fester points out putting the battery centrally by the back axle would be best for weight distribution but it just ain't going to fit and putting one big battery behind the passenger seat sort of negates half the benfits of moving it -I'm 6'1" and all legs so need the seat as far back as it goes. Hence my idea of twin small batteries behind each seat so the seats could still run right to the back of their runners.

Strangely, I do know quite a bit about Lead-Acid battery technology -I used to design solar-electric power systems with 2ton banks of individual 2V cells! It's all compromise -deep discharge cycles, self-discharge, cranking power, electrolyte consumption etc all trade off against each other and there's no easy 'one size fits all ' solution. Hence the Red Tops are likely to be dodgy in a road car used only on high-days and holidays.

Those Odyssey batteries look interesting though -two of those would fit neatly behind the seats without compromising the leg-room and 2x12V units wired in parallel would give plenty of cranking power, but having looked at their website the charging regime isn't straightforward ( back to the compromises!). Anyone any ideas as to how much they are or if they are available in the UK?

Failing that, i need something of roughly the same size and shape -hence the question if anyone knew anything about batteries from Nissan Micra's and other girlie runabouts? How big are they ( the batteries !!) and what's the cranking power like?

[lockhart flawse]

Following this with interest. We have a Citroen C1 and the battery is not much smaller than the one I have just replaced on my Griffith.

To try to avoid having to delve down into the footwell again my solution was to install the Leven Anderson connection under the bonnet and keep the car on an Accumate. This doesn't address the leg room problem though.

L.F.

[GreenV8S]

monoloco said:

Still don't like the boot option (with or without the folding roof option) -really not keen on having the battery up against the tank and all that weight hanging out the back....

The effects of moving the battery alone are going to be so small that it's academic, but yaw inertia isn't a particular issue with these cars. Traction is, and putting more weight over the driven wheels would be an improvement. Not a big enough one to be worth the effort if that was your only reason for doing it, but the practical issues associated with access to the battery would make this well worth doing imo.

Edited by GreenV8S on Wednesday 4th February 13:27

[spend]

I kind of struggle to see the problem with just sticking the battery behind the seat if you really want to? A simplistic diagram, but it shows the relative geometry works for you due to human ergonomics and the relative shapes available in the tub:

Always looks to me like it will give an improvement in legroom, easier access to both battery & fusebox and not so hard to implement using a battery cutoff switch and some extension leads? what more do you want?

[clive f]

don`t think your tub drawings quite right Dave

behind each seat is a step in the floor, it comes up about 2 to 3" or so, then goes back to the verticle bit, so that raises up the battery, hence pushing the seat forwards.

if it was a square corner if would be quite feasable.

Edited by clive f on Wednesday 4th February 13:27

[spend]

It's just an illustration of the comparison of the use of available space Cliff, not a technical drawing... There is actually a much greater effect than you describe on the battery due to the inner wheel arch IIRC? Both 'corner' details are actually compromised by the way the tub is contoured to accommodate the outriggers from memory?

The point is that if you look at the angles, more legroom will be gained by putting the box behind the angle you sit at. Putting it in front of the feet including the angled foot rest / [] / to wheelarch is a big waste of horizontal space? Its that trade off that I think can mainly give you a positive gain.

[monoloco]

clive f said:

don`t think your tub drawings quite right Dave

behind each seat is a step in the floor, it comes up about 2 to 3" or so, then goes back to the verticle bit, so that raises up the battery, hence pushing the seat forwards.

if it was a square corner if would be quite feasable.

Edited by clive f on Wednesday 4th February 13:27

Clive has hit the nail on the head -there is an awkward step in the space i'm talking about and if you tried to squeeze a single full sized battery in there you'd have to shove the passenger seat way too far forward. Ok you'd have gained a corresponding amount of leg room up front but the passenger would now be sitting a foot ahead of the driver and it would be a bh to get in/out.

I'll accept the weight hanging out the back with the boot option isn't going to be a disaster handling-wise but as good old Tescos say " every bit helps" and from what Fester says TVR wanted to put the battery midships in the first place for just that reason. My major concern is the danger of the battery being next to the tank -I've accidentally welded too many spanners to battery terminals in the past to want something that 'sparky' next to a tank in a smash

[GreenV8S]

monoloco said:

My major concern is the danger of the battery being next to the tank -I've accidentally welded too many spanners to battery terminals in the past to want something that 'sparky' next to a tank in a smash

I think it's likely to be a lot safer there than sat directly under the metal cased ECU, or under the bonnet waiting for you to rest your spanners on it.

If your fuel tank splits then I don't suppose it makes much odds how far away the battery is, you can light a pool of petrol from a hundred yards away if the wind's in the right direction.

[spend]

An enclosed boot full of nice oxypetrol fumes however does sounds like a perfect way to make a bomb But Beetles did it for many years IIRC?

[monoloco]

spend said:

An enclosed boot full of nice oxypetrol fumes however does sounds like a perfect way to make a bomb But Beetles did it for many years IIRC?

'spose I could always fit a couple of nozzles out through the rear panel and use it as a rocket booster

meanwhile think I'm going to look at those Odyssey batteries in a bit more detail.

(PS eff eff -idea is to stick the two in parallel ( ie +ve to +ve and -ve to -ve) rather than series so it stays as 12V but has double the Amp-hours and cranking capacity)