Battery to boot AGAIN

[adaxo]

Sorry to bring this up again as I read pretty much everything on previous threads about batt to boot conv, what I want to ask is which exact cable will be good for this as I don't understand this all AvG or square mm thingys so is any one can tell me which one will do for example this ad there (http://www.ebay.co.uk/itm/221711370270?_trksid=p2060353.m1438.l2649&var=520557150958&ssPageName=STRK%3AMEBIDX%3AIT)

[Pugme]

50mm is 0 gauge
25mm is 4 gauge

Personally I have 0 gauge running from alternator to boot.

[adaxo]

50mm is 0 gauge
25mm is 4 gauge

Personally I have 0 gauge running from alternator to boot.

lol but 50mm of what?

[Davezj]

here is some wire gauge current carring capacity but only rough values.

73352

73353

73354

by the way you AWG (American Wire Gauge), SWG (Standard Wire Gauge) they are not the same you also have cross sectioal area in mm2.
If you have 4 AWG and 4 SWG they have different cross sectional area.

[Davezj]

lol but 50mm of what?

50mm2 is cross sectional area.
pie x R squared = area of a circle

area / pie (3.1415) then take square root of answer = radius

radius X 2 = diameter of cable

50mm2 area conductor is about 8mm diamiter of conductor.
insulation is not included in the calculation .

here is calculater for the diameter from the cros sectional area
http://www.ookingdom.com/metric/diameter

[Davezj]

16mm2 cable = 4 to 6 AWG

if you read off the tables say for 6 AWG at 12V over a distance of about 15 -20 feet the cable will carry about 100A
over 7 feet it will carry about 150A

but it all depends on which table you use.

[Davezj]

here is a table that takes into account of the insulation temp rating and standing (number of individual wires that make up the complete core of the cable)

this table is only correct for an ambiant temp of 30deg C

http://www.energy-solutions.co.uk/technical-information

[adaxo]

Davezj I may live close to Wigan but im not so good in subject of pies



Bloody hell, still not have a clue what you on about, just pls link to right thingy on bay and I will buy it, please.

[Pugme]

Lol, from that link you will be fine with 50mm cable.

Im running a 210amp alternator down 50mm cable to 2 2000 amp batteries

[adaxo]

Lol, from that link you will be fine with 50mm cable.

Im running a 210amp alternator down 50mm cable to 2 2000 amp batteries

Roughly how long? 5 metres will do? I thinking of doing it through grommet next to pass light and inside to batt on pass side of boot where that little storage is.

[Davezj]

i think you should be ok with the 35mm2 cable but if you can fit a 50mm2 cable then go for that, i know you wanted to try and keep as small as possible for routing issues.
you have only got a 100A or 120A alternator.

as for legnth it depends how you rout it, those orange jumper cables i had were 5 meters long and i think that should work as you would route it through the bulkhead and along the outside of the seats by the door then under the rear seats, along the outside of the boot floor on the metal under the raised floor. then pull it up to the battery box top.

but there are probably better ways to route it.

are you using that massive battery box you bought a while ago.

[adaxo]

are you using that massive battery box you bought a while ago.

No this box is gone long time ago, it was far to big almost for two batterys, I will try to trim this plastic floor tray and fit original batt tray from front of the car and secure batt by using original brackets.

[Davezj]

you need it covered in a sealed box to stop accidental shorting accros the terminal and due to the battery acid and potential fumes off it in the car.

better still get a gell battery rather than a liquid acid battery.

[adaxo]

I was thinking about it, and yes connection MUST be insulated but this is easy as I will get some plastic 'caps' for +, but I'm not sure about sealed box as lots on BMWs for example have a battery in the boot and they not in sealed box, standard (not gel) battery. or Merc A class, battery sits right under driver foots and they not sealed so wonder why and where this 'sealed box is a must' come from?

[Davezj]

it may just be a requirement for racing, but i would not want a lead acid battery inside the car with me without it being sealed. in a saloon the boot is a separate box effectively but an estate is open. i believe when a lead acid battery is charged it can vent off sulphur/acid gas from it. which is OK under the bonnet as it gets blown away by the airflow in the engine bay.
this is why when you are charging a battery off the car, you should never disconnect a battery before switching the power off to the charger as it can spark and usually does, and potentially the gas given off can explode with catastrophic results.

[jaspa]

As Dave says, A normal battery gives off a corrosive/poisonous gas as it charges, not a massive amount normally but still enough, I know the MX5s have a special lead-acid battery that has a vent on it which is plugged into a hose leading out of the boot so that the corrosive fumes can escape.

My battery died while it was off the road since january so I am just using a bog standard battery temporarily, but will be replacing it with a gel type as soon as it arrives.

[Pugme]

Also the cable doesn't haven't to run thru the car. You can route it under the car too, preferably not cable tied to your exhaust :-)

[swinks]

Adam, you will be fine with decent 0AWG cable, roughly 5m long (gies you peace of mind when cutting excess). Also 150A ANL fuse close to battery.
I've found quite convenient route through passenger compartment etc.

[swinks]

Here some pictures to give you rough idea how I did relocate.
73355733567335773358733597336073361

[adaxo]

Ok 5 metres of 50mm cable ordered from link above, thanks for tips guys. Regarding battery seal, i have Exedy battery like that one https://www.tayna.co.uk/EA640-Exide-Premium-Car-Battery-027TE-P7489.html and it seems like its sealed one, if I understand this right its so call maintenance free and can't be opened, and it has a little vent nipple on the side so I assume its vent so should be fine by fitting some pipe on it and route outside car?

Btw swinks have you got any link to recommend fuse?

[Davezj]

Ok 5 metres of 50mm cable ordered from link above, thanks for tips guys. Regarding battery seal, i have Exedy battery like that one https://www.tayna.co.uk/EA640-Exide-Premium-Car-Battery-027TE-P7489.html and it seems like its sealed one, if I understand this right its so call maintenance free and can't be opened, and it has a little vent nipple on the side so I assume its vent so should be fine by fitting some pipe on it and route outside car?

Btw swinks have you got any link to recommend fuse?

that sounds like the right sort of thing vent nipple on the side and pipe, should do the trick.
as for the fuse/braker, jafromobile has a battery in the boot mod for his elentra, and you know he does things properly, it might be a good idea to have a look at that and see how he does it.

it is not pretty but functional.
https://www.youtube.com/watch?v=jyrOX1zrhWU

[adaxo]

I think this will do the job?
http://www.ebay.co.uk/itm/12V-24V-DC-AUTO-CAR-MARINE-BIKE-STEREO-AUDIO-CIRCUIT-BREAKER-RESET-FUSE-INVERTER-/390999688324?var=&hash=item5b0965c484

[Davezj]

i would like to say that one of the things jafro points out is the alternator charge cable, which should go directly to the battery then the cars power should come from the battery. so the point at which the two cables come together should be the battery positive. so technically two separate cable should be run to the battery in the boot.

the reason given for this is the way the charging of the battery occurs. basically if you only run one cable to the battery in the boot you may not get a good charge to the battery due to single cable.

now i am not sure that this, so the best way to see what happens is to test it.
can anyone with a battery in the boot test the voltage across the cable withthe engine off and the engine on.

or adam can just connect the 5 m cable from standard batter terminal + to the battery and then the - battery terminal back to the car chassis.
then measure the charge voltage.
work doing for piece of mind.

[swinks]

i would like to say that one of the things jafro points out is the alternator charge cable, which should go directly to the battery then the cars power should come from the battery. so the point at which the two cables come together should be the battery positive. so technically two separate cable should be run to the battery in the boot.

the reason given for this is the way the charging of the battery occurs. basically if you only run one cable to the battery in the boot you may not get a good charge to the battery due to single cable.
Not true if relocation is well made. I had 2 years fautless driving without any issue whatsover.


or adam can just connect the 5 m cable from standard batter terminal + to the battery and then the - battery terminal back to the car chassis.

That's how I have done mine.

[swinks]

Adam, I used this holder and 150A fuse in-line 20cm away from + battery terminal:
http://www.ebay.co.uk/itm/AUTOLEADS-SN4-20-0-GAUGE-CABLE-INLINE-ANL-FUSE-HOLDER-FREE-FUSE-OF-YOUR-CHOICE-/400395506483?var=&hash=item5d396e9333
and ANL fuses:

http://www.ebay.co.uk/sch/i.html?_odkw=anl+fuse+holder&_sop=15&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xanl+fuse+ 150a.TRS0&_nkw=anl+fuse+150a&_sacat=0

[adaxo]

Ok one last thing which I need some advice. What to use to connect new cable with current one under bonnet? Is there any special connectors for such a thick cable?

[Davezj]

i would either solder and sleve with heat shrink
or
use a connection block.
i will see if i can find the one i am thinking of.

this type of butt splice of correct size for your cable then sleve with heat srink. they can be bought as a T butt splice as well.

i would recomend soldering with a blow torch as a 30W or 60W solder iron will not get the cable or butt splice hot enough to make a good joint.

http://www.ebay.co.uk/itm/Butt-splice-connector-for-120mm2-4-0-AWG-cable-suits-15mm-dia-cable-ALT-RB120-/380420628781?hash=item5892d6212d

[adaxo]

I think soldering 8mm thick cabe could be difficult, I've seen special crimps for them but they require massive tool to cripm them properly.

[Davezj]

before anybody else gets in there, "i am a massive tool"

put but splice into vice blow torch in splice to heat it up then blow tourch end of cable, put into splice and feed loads of solder in there. this is why the butt splice has a hole half way down the splice, to feed the sodler in.
the first cable goes in throught the bottom then you flip it over and do the other end from the bottom.

you can get high current push together connectors or you can get ring terminals for the ends of the cables and bolt them together, but it makes it more difficult to insulate.

http://www.ebay.co.uk/sch/i.html?_odkw=oawg+connector&_sop=15&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.X0awg+conn ector.TRS0&_nkw=0awg+connector&_sacat=0

[swinks]

Adam, try to find something like this, maybe some car audio shops have them:
http://www.ebay.com/itm/Stinger-0-Gauge-AWG-Power-Wire-Platinum-Coupler-SPT5210-1-0-Joins-Two-Wires-/400180597872?hash=item5d2c9f5470

That's how I connected cable in engine bay, plus on top good quality thick insulation.

[dazjb]

Heres how I did mine, in an FTO but the principal is the same ...


Battery dropped into boot with quick release terminals and a 140amp circuit breaker installed (top right of pic) ...

73385


I ran a 2 gauge (35mm) cable from the battery straight to the starter motor ...

73386


Cable then goes from the starter to this distribution block mounted beside the NS strut ...

73387


I use this distribution block as I would the positive terminal of the battery if it were in the engine bay so the alternator wire goes into it along with a couple of other permanent +12v feeds i need.

Measured the voltage to the battery today with the engine running and it was 14.30v

I also have similar gauge ground cable going from the battery to a point in the engine bay where I can tag all the grounds into. This might not be necessary but I had the cable already there feeding an amp so I put it to good use as it wasnt need anymore.


For the starter motor connections I used this style lug ...

73388

I didnt buy the crimping tool just to crimp 2 lugs, hammer on a flat surface did the trick nicely ... there not going anywhere.

[Davezj]

That is a great bit of information, thanks for measuring the battery voltage at idle , it is nice to know for an actual measurement.

nice idea with the positive terminal in the engine bay as can be really handy to have. do you have a make and model number for the termnial just reference as this looks like a nice way to bring the existing and new wiring together without too much difficulty and it has been designed for the job reather than using audio connectors and the like.

[Pugme]

I've used a fair few of them lugs now :-)

https://scontent-lhr3-1.xx.fbcdn.net/hphotos-xta1/t31.0-8/12015093_842575499190700_4475172971691605112_o.jpg ?efg=eyJpIjoidCJ9 not sure if that'll work as a link, I'm on my phone.


http://pages.ebay.com/link/?nav=item.view&id=251621068796&alt=web

There's an eBay link tho