TWIN BATTERIES: which is which?

[mj1226]

Hi,

2 questions here:

1. For the Surf SSRX LN130 2.4L 2LTD winter pack, There are 2 known batteries.
Which is the battery solely for the engine and which battery is dedicated for the accessories?


2. Keeping the same alternator, Could I add another battery in the back to power 3 audio amps?

Or do I need another higher amp alternator?


Would greatly appreciate your inputs,

MJ

[tweak'e]

1, neither. batteries are wired in parallel and not dedicated for starting or accessories.
also they have dual batteries as standard. winter pack adds things like fuel heater.

2, yes you can (depending on the laws in your country). if you need a bigger alternator depends on size of the amps.
also it depends on if your into competitions or not and what they allow.

you can also convert it so one factory battery runs the surf and the other factory battery is solely for your stereo (or winch etc)

[mj1226]

1, neither. batteries are wired in parallel and not dedicated for starting or accessories.
also they have dual batteries as standard. winter pack adds things like fuel heater.

2, yes you can (depending on the laws in your country). if you need a bigger alternator depends on size of the amps.
also it depends on if your into competitions or not and what they allow.

you can also convert it so one factory battery runs the surf and the other factory battery is solely for your stereo (or winch etc)

Thanks tweak'e!

2. No laws regulating number of batteries here. I don't know if I need another higher amp alternator.
So this factory setup alternator can power 3 batteries. 3rd one being the audio battery?
Nope, no competition, Just leisure of enjoying 3 audio amps playin beautiful audio.

How do we do that, to isolate one battery for the engine and the 2nd battery for accessories and all? You got a guide / diagram to this or a link that could help me?

sure would appreciate your info. Have a great day.

[BUSHWHACKER]

http://www.hiluxsurf.co.uk/showpost....50&postcount=3

[andy_enuff]

I've done exactly that..... And not my warning lights are all on dimly.... Checked several times, have rewired the grounds all to body and still no luck. Looks like a 4v drop across the relay but now I'm stumped.:.

[wishbone]

What relay did you use ?

[tweak'e]

How do we do that, to isolate one battery for the engine and the 2nd battery for accessories and all? You got a guide / diagram to this or a link that could help me?

sure would appreciate your info. Have a great day.

any easy way and i think a better way than already posted is to use a VSR (Voltage Sensitive Relay).
you will need to work out which side you want to be the surf's battery. i would fit a bigger battery (longer). one will just fit in passenger side, not sure of drivers side. if you use drivers side as main battery you would require a larger cable to go across the radiator to the starter motor.

sorry don't have time to draw a pic.

disconnect passenger side positive battery terminal, connect VSR between old battery terminal and battery post. connect stereo to battery post.

that way all the surfs electrics are powered by passenger side battery, second battery is charged via the VSR. stereo runs of 2nd battery.

the advantage of this is 2nd battery is only charged when after the main one has high enough voltage. with a plain relay setup you can flatten both batteries.

[andy_enuff]

Wishbone,

It was one of these, albeit a lot cheaper than this..

http://www.amazon.co.uk/Autoleads-18.../dp/B0046HJ31K

[Ambobeer]

I've done exactly that..... And not my warning lights are all on dimly.... Checked several times, have rewired the grounds all to body and still no luck. Looks like a 4v drop across the relay but now I'm stumped.:.

Where is the 4v drop, across the coil or the contacts? The coil should drop all 12v - the contacts SHOULD not drop anything. 4v is showing a very high resistance across the contacts. Is the relay clattering or buzzing?

[andy_enuff]

The 4v drop only seems to be across the coil, which did seem very odd. The relay doesn't seem to be clicking or going mad. It is wired to one of the thinner alternator wires that is only live when the alternator is spinning after the engine is running (the same one that goes to the battery light I believe) and to the body.

The switched side of the relay has:

Terminal 1: The fuse box feed that originally went to the battery +ve by the fusebox and the cable that goes to the other battery +ve (the one the starter is wired off)
Terminal 2: A cable to the battery +ve by the fusebox

Both batterys have good connections to the body.

[wishbone]

Check the fusebox wire for breaks - It may have got damaged when you moved it about, causing a poor connection.

Also make sure any cables you put in are big enough - I used 0 gauge on my split charge system.

Rob.

If you remove the relay and just join the 2 cables (the switched ones) together is there still a problem ?

[andy_enuff]

Distinct possibility that there may be issues with the fuse box wire - only because very rarely before i added the relay the battery would be flat - I put it down to the immobilser and not using the car too offten but starting it a lot whilst repairing.... however it would tie in with the theory.

I have a battery monitor on the second (accessory) battery, it's currently dropped right down to 10v, and jumps to 13.5v when the engine is running... but.... it has now taken to showing 13.5v then occasionaly dropping back to 11.8v-ish - which would signify that either the charge wire is broken or the coil wire from the alternator is broken. I am fitting a voltmeter to the starting battery fairly soon - which will tell me if it is one wire or the other...

[wishbone]

Are you sure the second battery is good ? What have you drained off it to make it drop to 10V ?

My money is now on a crap battery......

Rob.

My setup has a volt meter on the main batteries and the aux one and it usually shows the aux at .2V less than the main ones.

[Ambobeer]

The 4v drop only seems to be across the coil, which did seem very odd. The relay doesn't seem to be clicking or going mad. It is wired to one of the thinner alternator wires that is only live when the alternator is spinning after the engine is running (the same one that goes to the battery light I believe) and to the body.

Woah! Something seriously wrong here! From memory (and it's been maybe twenty years since I've played with one of these) there are three wires to an alternator. A big thick boy which charges the battery, a live which is there to "excite" the alternator (an alternator needs power to make power) and the other one sort of feeds back to make the battery charge light come on. I think this makes the battery light go off by equalizing the voltage at either side of the lamp. If you have 4v dropped across the coil you are only getting 4v to the coil, the other 8v is getting dropped across something else in series with this or your battery is only 4v.

The switched side of the relay has:

Terminal 1: The fuse box feed that originally went to the battery +ve by the fusebox and the cable that goes to the other battery +ve (the one the starter is wired off)
Terminal 2: A cable to the battery +ve by the fusebox

Both batterys have good connections to the body.

The later comment about battery voltage: A car battery is 6 2v cells in series, these add up to 12v. You charge them at around 2.25v per cell =13.5v. If you have 10v across the battery when not on charge, chances are you have a shorted out cell and need another battery. (if it's connected in parallel to the other it will lie and tell you 12 on a multimeter so you need to disconnect to check)