Hello all,

After my recent alternator fiasco - and the forthcoming proposed winch I am looking at the possibility of fitting a dual battery system into the truck.

I presume the simple and straightforward way to connect this is simply to connect the second battery in parralell to the existing, with a manual isolator between the two batteries, and it will receive charge alongside the starting battery as long as the isolator is not "off".

What are the drawbacks of this straightforward approach is there any real benefit to battery management systems and charge management systems? - I do not forsee massive use of the system to the point that the alternator would not be given ample time and oportunity to "catch up on charging the batteries back up however am open to advice.

suspect Lez will be th eman for this one ....

cheers

Malky

I would recommend staying single battery mate unless your running alot of heavy duty electrical equipment. Buy an oddessey/Optima deep cycle battery and checking you have a 90amp alternator over the 75 amp ones.

Thanks stick, it is a 90 amp alternator I fitted.

do you hae a recommendation on which optima or which odessey to go for?

Malky

Think yellow tops seem to be the choice for optima batteries

I recommend an oddessey, PC1500. I had 2 of these beastie's. Not cheap BUT quality never is and these tokk a hammering with me as you could imagine. I MAY be able to locate one of my old one's for you and strike you a good deal for a mint second hander,

Quote: malky wrote in post #1

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What are the drawbacks of this straightforward approach is there any real benefit to battery management systems and charge management systems? - I do not forsee massive use of the system to the point that the alternator would not be given ample time and oportunity to "catch up on charging the batteries back up however am open to advice.

suspect Lez will be th eman for this one ....

cheers

Malky

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Hoping not to contradict anyone, but I have my hydro cell running at 25A, the winch and all the lights running off a single numax deep cycle battery. granted I switch off the hydro cell when winching, and have had no trouble.Might be unnecessary expence and faff if your not gonna be using the winch alot Malky?

Basil

Malky, I think you need to add up the total draw of all electrics on the truck first to see if its needed. I've looked at this for the future; keep the main battery for starting and factory fitted electrics, all other ancillaries comes off the 2nd battery for redundancy. No matter what, you will always have the main battery to start her up and get moving; running a split charge would make sense. As far as I've understood, the 2nd battery could also be used for jumpstarting if needed. Numax battery's are excellent; cheaper than flash Optima batteries but sound the same job. Do all l200 K74's share the same alternator? If not, this would be a good addition to 'up' the charging and draw. If everything is on, winch, lights, stereo, etc, the charge off the alternator will realistically power these AND if there's enough, carry on charging batteries.

Quote: Stick wrote in post #2

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I would recommend staying single battery mate unless your running alot of heavy duty electrical equipment. Buy an oddessey/Optima deep cycle battery and checking you have a 90amp alternator over the 75 amp ones.

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I have a second battery. Much the same as Billys, except mine is in the tub. I used a 50 A relay and some 30A cable between them. But instead of triggering the relay on the ignition I wired in a manual switch. One of the missile switches next to my hand brake. I put it on a switch as the aux battery runs my pump in the tub and heater in the tub which are both used for work. I thought possibly that having the battery on the ignition might not charge it enough. Initially I would only lift the switch when I was driving, therefore only charging while driving. But I used to get low battery signals on the axillary battery quite often. I started lifting leaving the switch on over night every other night, thereby treating it as a true twin battery system. And also leaving the switch on while working, thereby draining from both batteries while working. The inspiration for this came from realising that the Scandinavian trucks had two batteries on all the time. As did my old Hiace. Anyway, I don't get low battery signals from the axillary battery any more. Though that said I am exploring the idea of a solar charger for the roof. That or one of Sticks alternators. Don't know if any of this is useful....

well thanks for all the info guys.

To be fair the hilux surf my better half had a winter pack which included dual batteries it just seems like a smart move to have a dual system if there isn't a financial or practical reason not to.

I do have the 90 amp alternator fitted so possibly i will start with an optima for now and consider where, how and if I want to go down the dual battery route later.

thanks again guys as always informative and intelligent answers, impressed no-one wandered off topic

cheers

Malky

Quote: TwedL200 wrote in post #9

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Quote: Stick wrote in post #2

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I would recommend staying single battery mate unless your running alot of heavy duty electrical equipment. Buy an oddessey/Optima deep cycle battery and checking you have a 90amp alternator over the 75 amp ones.

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how can one tell what current their alternator is?

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Isn't it written on the alternator? I think mine said 75 amp, but I could be wrong; it has been known!! I think there's a label on the upper surface

Just checked... factory fitted on a 55 plate warrior is 75 amp. Does that mean it pumps out UP to 75 per hour or what??

75 Ah means that the battery can deliver 75 Amps for 1 hour of time................ when brand new.
This also means it should deliverr 1 Amp for 75 Hrs or 2 Amps for 37.5..........
Just using the other calculations as examples so's peeps can see how the battery ratings work....
I could never be facaetios............. or take the 9155..

You Lez; never! Good to have a better explanation thou

that means it is capable of a peak current of 75a output.

So, If you had a battery rated at 750Amps then it would take 10 hours to charge the battery from dead flat.
In theory.

however, you have cable losses etc to deduct from that so expect it to support a constant load of maybe 30a or so.

I also have a little solar panel on the roof, seems to put out enough juice to make up for the alarm led's etc but that's about it. Won't charge a dead battery. I have some bigger panels that are a better output but they are to expensive to stick on the roof of the thing. I will mount one inside the back window one day..

Quote: Stick wrote in post #2

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I would recommend staying single battery mate unless your running alot of heavy duty electrical equipment. Buy an oddessey/Optima deep cycle battery and checking you have a 90amp alternator over the 75 amp ones.

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The alt is/should be marked with 75/90amp.

Thanks stick. Will be interested to check mine.

I would hazard a guess at 75amp fella.

I think that running the car, 4x 55W spots and a nuke ( about 30A) all at the same time may be a bit too much for the standard alternator then but you're never gonna be running all of them at the same time for prolonged periods of time are you... If you had a nuke fitted that is. (One day hopefully )

You can get standard alternators re-wound to higher outputs can't you?