[Pat_T]

Hi all,

Not sure which forum section this is most relevant for..?

I want to remove my battery and install a lightweight motorsport battery in the boot. I just wondered how exactly the best way to go about doing this is? Is the easiest way to simply run two long battery cables from the existing +pos and -neg terminals under the bonnet back to the boot (under the carpet?), attach to the battery, and create a new earth point (on bare chassis metal) in the boot?

thanks,

Patrick

[Alan m]

Pat, you only have to extend the (+) lead. Just connect the (-) terminal to a good clean chassis point in the boot.

I don't run a standard Puma so not sure if there are any secondary wires on the existing (-) lead. If there are then simply connect these to the chassis (-) point in the engine compartment.

[Shilly]

they will be more resistance if you extend the cable so more power will be needed to cope
also if you are still running heaters and the likes you will need a battery that will cope with at least 70 amp hours
most motorsport batteries are not powerful enough to run a car day to day
if you want ne that can run your radio and the likes it will cost you alot more then its worth to do this

[Alan m]

Shilly, on 28 October 2009 - 09:07 PM, said:

they will be more resistance if you extend the cable so more power will be needed to cope
also if you are still running heaters and the likes you will need a battery that will cope with at least 70 amp hours
most motorsport batteries are not powerful enough to run a car day to day
if you want ne that can run your radio and the likes it will cost you alot more then its worth to do this

If you mean gel type batteries they are more than adequate. Think your forgetting one thing, the main purpose of the battery is to supply power to crank the engine. The alternator will be providing the power once the engine has started, its position in the scheme has not changed. With regards to voltage drop in the extended cable, if you use some flexible battery cable (175-220amp) the voltage drop will be insignificant.

This post has been edited by Alan m: 30 October 2009 - 06:20 PM

[warrenpenalver]

the battery is not just there to crank the engine. It does also balance the load when the engine is at low revs and has a high load from say heaters, wipers, headlamps, radio etc. Also you will find as alternator gets older and less efficient then if you have a smaller capacity battery then the car will die well before would be expected for someone with a bigger battery.

[Alan m]

warrenpenalver, on 30 October 2009 - 09:16 PM, said:

the battery is not just there to crank the engine. It does also balance the load when the engine is at low revs and has a high load from say heaters, wipers, headlamps, radio etc. Also you will find as alternator gets older and less efficient then if you have a smaller capacity battery then the car will die well before would be expected for someone with a bigger battery.

Who said it was only for cranking the engine?

An alternator is regulated and is very efficient at low rpm and will loose very little, if any, efficiency with age. It may become faulty but that's a different thing altogether and no car battery, no matter what its capacity, will have redundancy factored in for that scenario.

A gel racing battery of the right capacity (Red Top 40 or 60) fitted in the boot will operate the same as a conventional battery in the engine compartment, done it got the t-shirt. Thing is some people like to put up obstacles to modifications with no knowledge of having actually tried the mod.

[Shilly]

Alan m, on 30 October 2009 - 05:11 PM, said:

If you mean gel type batteries they are more than adequate. Think your forgetting one thing, the main purpose of the battery is to supply power to crank the engine. The alternator will be providing the power once the engine has started, its position in the scheme has not changed. With regards to voltage drop in the extended cable, if you use some flexible battery cable (175-220amp) the voltage drop will be insignificant.

i dint say they are not but i think you will need a red top 40- 60 which are alot more expensive then a normal battery my main point was not that it will not run the car just the specific red top battery to run a car with radio / heaters etc will cost alot more then a standard battery
i have also been there done it and in the process of doing it again with my new track toy

192 cheapest 40
http://www.google.co...F-8&sa=N&tab=wf
300 quid on a battery :s
http://www.google.co...=N&hl=en&tab=wf

imo i would go for a performance mod to increase bhp over that sort of mod

This post has been edited by Shilly: 01 November 2009 - 09:44 AM

[Pat_T]

Alan,

Thanks for your help would any of these be ok?

http://www.odysseyba...pc680series.htm

I have experience of using them in conjunction with 2.0 Vtec engines, also running headlights, race radios, and a pneumatic compressor for paddleshift and they seemed to hold up ok for 12 hour races! I can get them for around £90

This post has been edited by Pat_T: 02 November 2009 - 10:00 AM

[Matt & Tiggr MKIII]

Tiggr has a boot mounted battery - caused a few headaches initially, but worked a treat once cabling issues had been resolved.

Just make sure that the mounting box is right up against the back seat when its upright. Those batteries are heavy and you dont want it flying around the cabin if you get shunted...

And a photo...

This post has been edited by Matt & Tiggr MKIII: 02 November 2009 - 11:36 AM

[JCDenton]

Quote

they will be more resistance if you extend the cable so more power will be needed to cope
also if you are still running heaters and the likes you will need a battery that will cope with at least 70 amp hours
most motorsport batteries are not powerful enough to run a car day to day
if you want ne that can run your radio and the likes it will cost you alot more then its worth to do this

lol, if you find you are getting a noticeable amount of resistance in a few meters of cable your using the wrong gauge wire and its going to burn out. I recommend having a fuse on the positive cable as close to the battery as possible, if the cable grounds your battery will explode.. or use armoured cable. Make sure the ground cable connection is clean and secure.

[Alan m]

Pat_T, on 02 November 2009 - 09:58 AM, said:

Alan,

Thanks for your help would any of these be ok?

http://www.odysseyba...pc680series.htm

I have experience of using them in conjunction with 2.0 Vtec engines, also running headlights, race radios, and a pneumatic compressor for paddleshift and they seemed to hold up ok for 12 hour races! I can get them for around £90

Pat,

It depends what you intent to use the car for. If it's everyday motoring I'd say the A/H (16) is a bit low. I run a Red Top 30 in my rally car, on night stages i'm running over 500w of light, heated screen, wipers etc and lots of starts on the engine and never had any issues. If it's everyday motoring I'd go for the Red Top 40 or 60, I reckon the 40 (38A/H) would be more than man enough. I think they come in around the £160 mark, a wee bit pricey but last a very long time in comparison to a wet cell and can be brought back to life even if left for long periods discharged .

[Pat_T]

Hi guys,

Thread ressurection time!

I've decided on the Red-Top 40, and this weekend I ran some 280amp flexible battery cable from the boot, under the carpets, and upto the bulkhead in the rear passenger footwell.

Now has anyone got an advice how can I get the cable through the bulkhead to the terminals under the bonnet WITHOUT removing the dash? I have plenty of length to play with...

cheers,
Patrick

[FlashBastd]

Go through the grommet in the engine bay, and reseal with silicone.

I ran a number of cables through the inside of the grommet (rather than cutting it), but they were much smaller gauge.

[Alan m]

As suggested by Flash I'd try for an existing grommet or drill and fit a new grommet in the pass footwell.

One other option is a 'through' bulkhead fitting, see below.

http://www.merlinmot...oduct_info.html

[alan12666]

Alan m, on 08 February 2010 - 05:37 PM, said:

As suggested by Flash I'd try for an existing grommet or drill and fit a new grommet in the pass footwell.

One other option is a 'through' bulkhead fitting, see below.

http://www.merlinmot...oduct_info.html

Pat,

Alan_m's advice is spot on - I've got a RedTop 25 (I think ... might be 30) in the back of my stage car, I ran the calble through the existing wiring grommet by the main fusebox, but that was only really possible as I pulled out a load of other wires I was doing away with. I know others who have used the bulkhead connectors succesfully.

As these are critical connectors and hard to get at, I'd also suggest using nyloc nuts and copper grease on the contacts. Good luck!

Alan