Car Batteries and Relocation Kit's Q&A

[LeaThaL]

Hey all,

as usual ive done the normal 1jz/mz20 swap and due to piping ive relocated my battery to the boot, i dont know too much about batterys so ive had some issues and ive talked to a few battery places and they insist on 300/400 dollar batterys without telling me what their good for and what not so i was wanting to get other peoples options.

im currently using a 250amp wire running straight from the battery to the starter with the fusebox wired into it and the battery i had was crap so i put in a 540cca 4wd battery and thats enought to get it started but it wont turn the car over first time i turn the key, i have to hit it untill it turns over and if i just hold it to turn over and not start the engine it will turn over a few small times and then stop

i would guess that is do to with someother ratings on the battery, so what im asking is are these normal signs of a battery that isnt up to being so far away and what ratings are needed as i just purely know nothing about batteries

cheers

[hogesjzz30]

i did the same thing with my MA70 and used 2 gauge wire, i just went to a mechanics that sold batteries and asked for one for a Ma70 battery and its been working fine ever since.

[RA35GT]

a 540cca battery is more than big enough. make sure it is fully charged. (That battery is massive and should work awesomely)

You need to check your wiring and make sure there is an adequate earth from the engine to the car and from the car to the battery.

[LeaThaL]

i let it charge for 3 days so it should be fully charged, and as for earthing i earthed the battery straight to the chassis with a decent gage 1 piece earth you can buy from autobarn. and i got a few random ones on the engine, 1 from AC bracket to chassis, 1 from turbo inlets to firewall, 1 from chassis to inlet and 1 on the gearbox, when it does fire its fast and pumps hard but it dies like 4-6 cycles along

[RA35GT]

Hrm. Is the earth on the battery the same size as the power cable on the positive?

Turn headlights on,

Crank the engine. if the lights go really dim the battery is flat.

If the lights stay bright you may have a dud starter motor or solenoid. (or dodgy wiring)

[LeaThaL]

yeah seems so, if anything its slightly bigger, and i will try that headlight trick once ive installed globes, for some reason i didnt have a single bulb in the car when i got it

and it could be a starter issue as when i hit the key it will go like this

1st kick you just hear a click like the pin on the starter just pops in and out really quick
2nd kick does the same
3rd will do it again.
4th may do nothing
5th will turn over straight away really strong for about 6-7 turns and then quickly slow down to nothing and just die,

but i can repeat the process and it will do the same things but but in different order. my turbo timer will read a consistant 12.4-12.9 reading for all atempts to start the car,

[Adash=P]

Try running a cable from the motor (earth) to the battery. Also try this http://www.toymods.net/forums/showthread.php?t=3334

[RA35GT]

Another thing to try,

Hot wire the starter and make sure it works correctly. (Take 12V and apply to the small terminal).

You may have a dodgy ignition switch?

Running jumper cables from battery to the starter motor is also a good suggestion. (to rule out dodgy cabling)

[LeaThaL]

nice info, i missed that one in the search thanks mate! lucky a jaycar opened just up the road

You may have a dodgy ignition switch?

Running jumper cables from battery to the starter motor is also a good suggestion. (to rule out dodgy cabling)

the ignition switch should be fine as it worked fine before i swapped the battery to the boot,


and i was going to buy some jumpercables this week and try just sitting the battery near the front and just seeing if that worked but it was just a simple wire and earth setup so yeah



one thing i was thinking that might have some play in it is that i have the earth on the chassis on the drivers side but the starter is on the passenger side but i wouldnt think that would change anything logicly

[petergoudie]

If the battery is OK it is voltage drop due to the long length of wire. You can check this with an analogue multimeter (one with a needle). A digital meter will not stabilise and you won't get a true reading. Also, how are the ends of the wire terminated. Solder them if you can.

I have an MX5 with battery in the boot as standard and it struggles to crank the engine as supplied by Mazda new. Even with a new battery, there is enough voltage drop if after about 10 days you haven't driven it, it won't crank.

Check with welding suppliers and on ebay for multi-strand flexible welding cable.

Also, those heavy gauge flat earth straps can have low current ratings even though they look good. Jaycar sells one that could be used in a car but it's rating is only 100amps.

[RA35GT]

nice info, i missed that one in the search thanks mate! lucky a jaycar opened just up the road



the ignition switch should be fine as it worked fine before i swapped the battery to the boot,


and i was going to buy some jumpercables this week and try just sitting the battery near the front and just seeing if that worked but it was just a simple wire and earth setup so yeah



one thing i was thinking that might have some play in it is that i have the earth on the chassis on the drivers side but the starter is on the passenger side but i wouldnt think that would change anything logicly

Your right dood, it shouldn't change anything (as long as the cable is terminated correctly, the engine block is a hugeee conductor

[CELICASUPRA7M]

definately try hotwireing starter with jumper cables if the starters easy to get at, this will rule out and starter wiring. what was it like before you put the battery in boot? the battery is plenty big enough.

[LeaThaL]

i thought it might of been voltage drop from the length and thus why i tryed the 4wd battery.

yes i soldered the ends in using decent ring ends i got from the same place as the wire, and i replaced the positive terminal with a big brass one with a wingnut on it and its all nice and tight, the negitive is one solid piece, this is the pic i have in my members ride thread



and by heavy gauge flat earth straps, you mean the ones about 10ml wide? as i havent used anything like that for an earth, ive used the standard located and issued earths, and then i added 3 or so more using what i think is like 8 or less gage wire with soldered ends sent to the chassis

thanks for all the info so far too folks, REP is with every post

[CELICASUPRA7M]

so in the boot you have the earth wire from the battery bolted to the body? did you scrape all the paint off where the wire contacts? if worst comes to worst, run the earth from the battery all the way up to the front like it is in stock form.
good luck

[LeaThaL]

so in the boot you have the earth wire from the battery bolted to the body? did you scrape all the paint off where the wire contacts? if worst comes to worst, run the earth from the battery all the way up to the front like it is in stock form.
good luck

yeah its on one of the bumper chassis bolts, i sanded the point and then put the standard washer over the top so its super down and flat,

i just went out there then and had a play and it seems to be kicking over first time now but is still stopping after a few turns but im guessing thats just voltage drop as peter suggested so i might buy some earth straps this week and redo them with something stronger and see if the drop gets better