Dual Battieries

[lhurley]

Hey guys,

Ive got a piranha offroad dual battery isolator (DBE140), that appears to have died. It was in the car when i bought it over a year ago so its condition/history is unknown.
Its not charging the 2nd battery and showing only 1 red light. I have cleaned everything and made sure its all tight. Originally i thought it was not charging due to a faulty alternator, but the alternator and cranking battery have since been replaced (only a couple days ago)

I want to get a dc - dc charger, but cant afford one right now. I still want to use the 2nd battery though, is there a way i can do a cheap dual battery set up until i can get a dc - dc?

Any help much appreciated

Cheers
Lachlan

[TimE]

Good old Redarc Isolator, $88 on Evil bay (http://www.ebay.com.au/itm/EXPRESS-POST-REDARC-SBI12-DUAL-BATTERY-12V-12-VOLT-CHARGER-SOLINOID-ISOLATOR-/400366704519?pt=AU_Car_Parts_Accessories&hash=item5d37b71787)

[the evil twin]

Any solenoid or relay will do the job on the cheap with a toggle switch to control it.

There are heaps of dual battery installations around where people just used an old solenoid they had lying around and haven't bothered wth the automatic Voltage Sensing Relay Kits (Redarc, Piranha etc).

Is your dual battery a lead acid in the engine bay?
If it is then you don't need a DC DC setup as there is bugger all voltage drop between the Alternator and Battery so the DC DC jobbie won't be doing anything.
DC/DC Chargers are for where you have a long run of smaller spec cable between Alternator and Battery such as charging the battery in a Caravan or Camper from the Vehicle Alternator

[lhurley]

Any solenoid or relay will do the job on the cheap with a toggle switch to control it.

There are heaps of dual battery installations around where people just used an old solenoid they had lying around and haven't bothered wth the automatic Voltage Sensing Relay Kits (Redarc, Piranha etc).

Is your dual battery a lead acid in the engine bay?
If it is then you don't need a DC DC setup as there is bugger all voltage drop between the Alternator and Battery so the DC DC jobbie won't be doing anything.
DC/DC Chargers are for where you have a long run of smaller spec cable between Alternator and Battery such as charging the battery in a Caravan or Camper from the Vehicle Alternator

The current 2nd battery is a lead acid in the engine bay. But I want to change to a deep cycle. The plan is to get the good charger before the better battery so is to not damage it with a insufficient charger.
If a vsr such as the redark jobbie will be suitable, then that's what I'll get.

[the evil twin]

The current 2nd battery is a lead acid in the engine bay. But I want to change to a deep cycle. The plan is to get the good charger before the better battery so is to not damage it with a insufficient charger.
If a vsr such as the redark jobbie will be suitable, then that's what I'll get.

Hi cobber,

Yeah if that is the case then a "standard" VSR isolator will work just fine.

DC DC starts to be a consideration if you are using more 'exotic' 2nd battery technology like calcium/calcium etc that need higher than standard charging voltages OR you have a long run to the 2nd battery OR you want to involve Solar Panels when camped or whatever

[lhurley]

Hi cobber,

Yeah if that is the case then a "standard" VSR isolator will work just fine.

DC DC starts to be a consideration if you are using more 'exotic' 2nd battery technology like calcium/calcium etc that need higher than standard charging voltages OR you have a long run to the 2nd battery OR you want to involve Solar Panels when camped or whatever

Sweet as. Thanks bloke.

So a normal run of the mill deep cycle will get charged fine? Or be fine with a vsr then get put on a home charger every so often?