surf double battery replacment?

[BigRedCruiser]

Howdy my surfs batteries are starting to give up on life and my dad in a panic a few months back bought himself a deep cell car battery for his teranno which being a single battery setup died reguarly.
My idea is to 'commandeer' that deep cell batt and have it in my surf with a high cranking batt for starting and the deep cell so i kan run my sounds for ages =) its a 95 ssrx 1kzte surf
would that setup work or is it asking for problems i no nothing bout this so some ideas wuld be great! cheers

[tweake]

have you got the standard paralleled batteries or two separate batteries?
sorry not sure on the 1kz setup. i'm converting my ln130 to single battery at the mo. the stock setup is poor.

if its standard paralleled then both batteries need to be the same.
if you want a cranking battery and a run battery you will need a voltage switch in between them so they are not not in parallel until alternator is charging.

[mike77]

I suppose you could run a VSR (google that) set up, like alot of boaties do. That way everything is automatic.

(Don't have it myself - just 2 marine batteries and switches in the waka, more simple like me)

Also if the deep cell has been fried - it's toast anyway. I heard there is a firm in aucks somewhere that can refurbish them, but I don't know enough to recommend it to anyone.

[Finn68]

I've just done this in mine.

http://www.projecta.com.au/cataloguepages/asset_id/9/

I run a heavy duty cranking battery and using the above system have an automatically isolated deep cycle battery for stereo, LED work light and spare 12v power outlets. The aux power is on all the time and the stereo has a switch between ignition power and aux.

Once the main cranking battery is at 13.5v (i think) the alternater then charges the aux battery. There is an override where you can connect them together if your cranking battery is flat but a deep cycle battery is not desinged for this type of work so should only be used in emergencies.

[UBZ]

I run twin 600CCA battery's in the stock parallel setup .
The twin setup is the factory 'winter package' , as the 1KZ starter motor is 90amp from memory.

I certainly appreciated having the starting grunt in the snow yesterday. The starter had to work hard.
I'd be looking for a 1000CCA + battery to replace it in a single battery setup.

I wouldn't use a VSR with a winch, as full winch load (300+amps) can be drawn through the VSR. from 1 battery to the other as they try and exqualise. this = melted VSR or Winch or Battery or All.
Thier is also the possibitty of overcharging and cooking your second battery with a VSR if the battery has no load on it.

[curious_george]

I wouldn't use a VSR with a winch, as full winch load (300+amps) can be drawn through the VSR. from 1 battery to the other as they try and exqualise. this = melted VSR or Winch or Battery or All.

BEP Marine (a Kiwi company in Auckland) make a VSR they call a "Voltage Sensitive Battery Switch" http://www.bepmarine.com/home-mainmenu-8/productcategory-97/voltage-sensitive-battery-switch The more expensive unit (around $320) will handle 500A continuious and up to 1500A surge, so it'll do the job. I think the smaller one from memory will handle up to 1250A surge, so that'll still cut it pretty easily.

Thier is also the possibitty of overcharging and cooking your second battery with a VSR if the battery has no load on it.

Could you elaborate on this one a bit more for me please? Is this a problem that happens on boats and house busses too?

[muddyhilux]

i cant say i know much about batteries and how they work but i had a deep cycle as my starting battery for ages,then added a standard battery in parallel and ran like that for ages and both batteries are still going strong

[sibainmud]

All of the problems above, come down to set up. I have worked with VSR's since Version 1.2 in the late 80's when they were rated at 30amps
Since then I have had regular contact with the techie at BEP and they have ironed out the glitches by applying delays and dual sense.
My present VSR is version 12a with dual sense and a rating of 125amps
http://www.bepmarine.com/home-mainmenu-8/product-270/dual-sense-voltage-sensitive-relay-125amp-vsr-
When configured correctly the VSR disconnects when using the winch.
Hope this helps.
Cheers,

[sibainmud]

There is also the possibility of overcharging and cooking your second battery with a VSR if the battery has no load on it.

If you run the alternator sense wire to the right place, it remedies this issue too. Any ways, as the VSR is a switch the alt can sense the second battery unlike blocking diodes. It does pay to have the same size and age batteries in the basic set up

Cheers,

[UBZ]

There is also the possibility of overcharging and cooking your second battery with a VSR if the battery has no load on it.

If you run the alternator sense wire to the right place, it remedies this issue too. Any ways, as the VSR is a switch the alt can sense the second battery unlike blocking diodes. It does pay to have the same size and age batteries in the basic set up

Cheers,

Regardless of single or dual sense , when the alternator is outputting charge current onto the battery, the voltage raises over 13volts and the VSR opens .
Therefore if your second battery has no load it still receives a full charge current which will eventually overcharge and cook the battery .

I had a VSR setup to run an inverter that was not used a lot. The battery died , was professionally tested , then cut open . The verdict was the battery had died due to constant overcharging every time the vechile was run.

Effectively when ever the vechile is running the 2 battery's are paralleled together through the VSR . In a winching senario , the battery with the winch is under heavy load and will try to equalize with it's paralleled pair through the VSR .
My 9000lb winch draws 380amps at full load , this is more than double the continous amp rating of the general 150amp VSR .

Even when the sense is setup to the winch battery, full winch load current is generally drawn through the VSR before the winch battery drops below the 12.8volt threshold and isolates the batteries .

A VSR is great for running fridges , lights , radios etc. It ensures you can always start the vechile in the morning , but in my opinion I wouldn't use one in a winch setup unless it was rated to handle full current of the winch.

[sibainmud]

I will concede that this would be the case in that instance. Understanding this, i have shared the loads between the batteries like this.
The large battery (N120) in the rear is hooked to the alt output and powers the glow plugs, starter, winch and the head lights (high and low beams) and also has the sense from the alt hooked to it as well. This leaves the standard battery (N70) running the radios, instruments and everything else and is the secondary battery on the VSR. When winching the voltage instantly drops and the VSR disconnects. Even if it was to stay latched in, the heavy load can never pass through the VSR.
After a long winch it can take some time for the N120 to recover and raise it's voltage up over the 13.7 volts needed to latch the VSR back in. It all seems to work for me anyway
Cheers,

[UBZ]

. When winching the voltage instantly drops and the VSR disconnects. Even if it was to stay latched in, the heavy load can never pass through the VSR.

this is not correct if the vechile is running. your alternator will be outputting a full charge voltage of 13+volts . the VSR sense terminal shares the same positive power circuit as the alternator charge circuit . therefore the VSR will stay open regardless of what voltage the battery is actually at.

As the VSR is a simple latch switch and has no internal diode(1way) function or overload cutout, full winching current can be drawn back through it . I have seen 2 VSR's melted in this manner.

[Sadam_Husain]

I have seen 2 VSR's melted in this manner.

I melted a big hole in one and all the smoke escaped but the BEP one I replaced it with always stayed intact and never melted, cant remember the rating on it but I remember the 100 bucks it cost me

[DieselBoy]

I melted the vsr on Thunderguts doing the Waitawheta truck.

Same thing, winch battery was low, engine battery was high, vsr was switched over to charge the winch battery as a result. The winch tried to draw 900amps through the vsr as the winch battery was flat.

I had the electric engine fan, the electric trans cooler fan, the lights and the engine running off the engine battery, that was enough to draw the system voltage down to the point where the vsr wasn't charging the winch battery.

I turned all that stuff off, the voltage on the main system came back up so it switched over and started charging the winch battery. Then when I started winching, because the battery was flat it tried to draw through the vsr.
I chucked it all out and swear by running the two biggest batteries you can fit in parralel.

Vsr's are awesome for camping, tuning vested and lights etc, but useles for running a winch.

[wjw]

on the Prado, I used the primary battery for starting, winching etc. Then the secondary for aux stuff, prs, stereo, amp, lights etc. Had a VSR in the middle and also a 3 way 400Amp switch so I could go:

Aux <-> Main
Aux < VSR > Main
Aux < No Connection > Main