(Extra) battery in the rear? Anybody done it?
05-30-2003, 03:10 AM
#1
Drifting
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(Extra) battery in the rear? Anybody done it?
Tried searching the archives but only came up with <a href="http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic;f=36;t=002506#000000" target="_blank">just one thread</a>.
I've had some strange ideas lately about how nice it'd be to have a battery in the rear; either by moving it out of the engine compartment, or by adding another battery to carry some extra amp hours along.
Anybody done this already? I'd very much like to see some pics...
If I'll put in the second battery, all I have to do is to pull huge *** heavy duty wires to the trunk and connect the two batteries in parallel, right? Would I have to worry about the alternator or something else?
As you can see, I'm not an electric expert
Thanks!
I've had some strange ideas lately about how nice it'd be to have a battery in the rear; either by moving it out of the engine compartment, or by adding another battery to carry some extra amp hours along.
Anybody done this already? I'd very much like to see some pics...
If I'll put in the second battery, all I have to do is to pull huge *** heavy duty wires to the trunk and connect the two batteries in parallel, right? Would I have to worry about the alternator or something else?
As you can see, I'm not an electric expert
Thanks!
05-30-2003, 03:17 AM
#2
Rennlist Member
Martin Taylor relocated his battery to the rear cubby in his '84 944. That's probably the best known example.
P.S. Batteries are heavy. Are you sure you want to haul 2 around?
P.S. Batteries are heavy. Are you sure you want to haul 2 around?
05-30-2003, 03:25 AM
#3
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I might need two to fuel my bling-bling stereo when I'm hanging around at some parking lot trying to look cool ... as soon as I get all that stuff installed, of course
(no, I'm not at all sure, it's just an idea)
(no, I'm not at all sure, it's just an idea)
05-30-2003, 03:39 AM
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Did you put in in the left cubby like it's on those RHD cars?
Since I'm dumb, could you explain what a manual solenoid is?
And I presume 0 gauge is really thick? (I'm used to measure wires by square millimeters)
Since I'm dumb, could you explain what a manual solenoid is?
And I presume 0 gauge is really thick? (I'm used to measure wires by square millimeters)
05-30-2003, 04:09 AM
#6
Nordschleife Master
Sami, I'd think twice about this weight issue from two batteries, also. This is fine for boats, even more batteries, but for a sports car ... no.
0 or 1/0 AWG (American Wire Gauge) is 53.5 mm square cross section. With two batteries, one in front and one in back, that is probably OK for the run to rear, but if you want to switch to just rear batteries you need to go bigger.
I assume the manual solenoid reference is to have a switch to shut that rear battery down and off circuit. Big fire risk and you may want to charge it different.
Read about sailboat electrical systems and you will understand.
If you end up doing this idea I have some 5/8" fireproof fiberglass sleeve that you can cover the cable with. It will fit over more than 5/8" cable like a chinese finger trap. USD $1 a foot and shouldn't cost that much to ship to Finland.
0 or 1/0 AWG (American Wire Gauge) is 53.5 mm square cross section. With two batteries, one in front and one in back, that is probably OK for the run to rear, but if you want to switch to just rear batteries you need to go bigger.
I assume the manual solenoid reference is to have a switch to shut that rear battery down and off circuit. Big fire risk and you may want to charge it different.
Read about sailboat electrical systems and you will understand.
If you end up doing this idea I have some 5/8" fireproof fiberglass sleeve that you can cover the cable with. It will fit over more than 5/8" cable like a chinese finger trap. USD $1 a foot and shouldn't cost that much to ship to Finland.
05-30-2003, 04:34 AM
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I bought my S2 and the battery is in the back left hand cubby hole. Under the bonnet, where I've seen the battery on other (generally American) cars, there is an alarm speaker!
Don't know if that's standard in Europe or not, but we do seem to have a lot of differences over the same model, that I've noticed. Such as, my S2 doesn't have air-con for a start (I guess it was an option), I don't have reflectors on the extreme front and rear sides, I don't have an air-bag, my battery is in the boot, I don't have a catalyst (and I think that means my output is a few bhp more than the USA cars) and my bumpers aren't as large as the American cars! There may even be more differences. Anyone any ideas?
Don't know if that's standard in Europe or not, but we do seem to have a lot of differences over the same model, that I've noticed. Such as, my S2 doesn't have air-con for a start (I guess it was an option), I don't have reflectors on the extreme front and rear sides, I don't have an air-bag, my battery is in the boot, I don't have a catalyst (and I think that means my output is a few bhp more than the USA cars) and my bumpers aren't as large as the American cars! There may even be more differences. Anyone any ideas?
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05-30-2003, 04:42 AM
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I dunno, I guess I'm a bit confused 
The two main reason I have for an extra battery in the back are 1) a lot easier to wire up amps and whatever else I might be putting there and 2) less chance to run out of battery when playing music with the engine off...
Of course the second point is pretty theoretical, and if I can get away with using just one amp in the back then the first point doesn't apply either. Can't get the idea off my head though
Regarding the fire risk, wouldn't that be avoided by just placing some generously sized fuses on the positive wiring, right next to the battery?
Dan, thanks for the offer on the cable cover, I'll let you know if I end up needing that!
Martin, having battery in the trunk is standard in RHD cars, it came from the factory that way. I'm not sure if anybody has a definite explanation, either it has something to do with the steering system getting in the way or not wanting to have the battery so close to the driver. The rest of the things you described are euro model goodies
The two main reason I have for an extra battery in the back are 1) a lot easier to wire up amps and whatever else I might be putting there and 2) less chance to run out of battery when playing music with the engine off...
Of course the second point is pretty theoretical, and if I can get away with using just one amp in the back then the first point doesn't apply either. Can't get the idea off my head though
Regarding the fire risk, wouldn't that be avoided by just placing some generously sized fuses on the positive wiring, right next to the battery?
Dan, thanks for the offer on the cable cover, I'll let you know if I end up needing that!
Martin, having battery in the trunk is standard in RHD cars, it came from the factory that way. I'm not sure if anybody has a definite explanation, either it has something to do with the steering system getting in the way or not wanting to have the battery so close to the driver. The rest of the things you described are euro model goodies
05-30-2003, 05:07 AM
#9
Nordschleife Master
Sami,
It depends on how you set things up and what you demand from them.
You are in Finland which is similar to Minnesota, my birth place. I have all sorts of relatives in your country and I think we are colder. Temps get cold and the starter sucks 400 or 500 amps on heavy oil to turn things over.
Well, you can arc weld at a lot less than that. So how do you put a simple fuse in that will take 400 amps, not have people blowing it in harsh conditions, yet will melt at a smaller short? Say 300 amps when your battery is tired?
This is the key problem I have not found a cost effective solution to. If one wants to spend a few $100 bucks, then there are some solutions.
And, BTW, major car companies haven't found a true solution either. Look at Benz and such.
It is a problem, can be solved, but not cheap.
It depends on how you set things up and what you demand from them.
You are in Finland which is similar to Minnesota, my birth place. I have all sorts of relatives in your country and I think we are colder. Temps get cold and the starter sucks 400 or 500 amps on heavy oil to turn things over.
Well, you can arc weld at a lot less than that. So how do you put a simple fuse in that will take 400 amps, not have people blowing it in harsh conditions, yet will melt at a smaller short? Say 300 amps when your battery is tired?
This is the key problem I have not found a cost effective solution to. If one wants to spend a few $100 bucks, then there are some solutions.
And, BTW, major car companies haven't found a true solution either. Look at Benz and such.
It is a problem, can be solved, but not cheap.
05-30-2003, 05:13 AM
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Dan, good catch - I wasn't thinking about such power draws... back to the drawing board...
Looks like it's a good idea to ask these things first instead of just going out, buying a battery and then trying to figure out how to make it work
Looks like it's a good idea to ask these things first instead of just going out, buying a battery and then trying to figure out how to make it work
05-30-2003, 08:09 AM
#11
Burning Brakes
</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by Sami951:
<strong>Dan, good catch - I wasn't thinking about such power draws... back to the drawing board...
Looks like it's a good idea to ask these things first instead of just going out, buying a battery and then trying to figure out how to make it work </strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Sami, why don't you just buy a "bigger" battery,
I mean with a more amps, or what do you call it.
I do actually have the same problem, with my stereo setup, cause I do have an amplifier and a subwoofer, so I can't run them too long without the engine runnin' ( already twice I have managed to get the battery dead <img border="0" title="" alt="[Wink]" src="wink.gif" /> )
Also my battery is pretty "finale", so in case you have some good idea for example a bigger battery or such, I'm all ears..
<strong>Dan, good catch - I wasn't thinking about such power draws... back to the drawing board...
Looks like it's a good idea to ask these things first instead of just going out, buying a battery and then trying to figure out how to make it work
</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Sami, why don't you just buy a "bigger" battery,I mean with a more amps, or what do you call it.
I do actually have the same problem, with my stereo setup, cause I do have an amplifier and a subwoofer, so I can't run them too long without the engine runnin' ( already twice I have managed to get the battery dead <img border="0" title="" alt="[Wink]" src="wink.gif" /> )
Also my battery is pretty "finale", so in case you have some good idea for example a bigger battery or such, I'm all ears..
05-30-2003, 01:22 PM
#12
Three Wheelin'
I'd be very impressed if your stereo could kill a battery in appreciable time...I left my foglights on all night, started up in the morning. I realize that's only about 100W, but...for a few hours at the beach, I think you'd be alright...unless you've got some serious stereo plans.
Wiring a battery to the back would be a much bigger pain than running wires to an amp.
Wiring a battery to the back would be a much bigger pain than running wires to an amp.
05-30-2003, 08:23 PM
#13
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I moved my battery to the rear right cubby, this was done to eliminate the rust problems in the front tray, I used 25mm2 copper cable, I used the right cubby as the sun roof mechanism is above the left and in the way, works a treat.
Only the series two cars came with the battery in the rear in this part of the world.
Only the series two cars came with the battery in the rear in this part of the world.
05-30-2003, 08:55 PM
#14
Three Wheelin'
I am running the largest battery that I can fit in the battery tray and my stereo will kill it in less than 1 hour. I too have been thinking about putting in a 2nd battery for the exact same reason.