Duel battery solenoid or DC to DC charger

[Scomonethzoe]

G'day guys,
I have been doing some research on a duel battery systems and thought I had decided on a projector unit. However after speaking with a guy at battery world his suggestion was a DC to DC charger. He said
that to properly charge the deep cycle battery in the patrol I would need it. I have read up and seems to be true but also know how popular the solenoids are.

Any suggestions

Cheers Scotty

[kevin07]

im with ctek 250s dual

[Hodge]

I'm about to install, a Redarc 25A dc to dc unit (BCDC1225). Fully charged batteries, plus an option for solar implemented in it too.

[FNQGU]

Quite a few threads already on here covering that exact topic mate. Personally I'd go the DC DC charger but you probably want to work out your needs. Use the search function and you'll find heaps.

[the evil twin]

If your aux battery is close to the cranker, connected with decent gauge wire and is not Calcium or whatever technology that requires a higher than normal alternator output then the Projecta is fine and you do not need a DC/DC charger.

The fact that a battery is a deep cycle or not is totally irrelevant to whether it "needs" a DC/DC unit.
DC/DC is only required for technologies that like a higher charge voltage or where there is excessive voltage drop between the charging source and the aux battery like in a caravan or rear mounted battery with small gauge cabling.

Another disadvantage is that you cannot back feed thru most DC/DC units IE use the Aux to start if you have a flat cranker or winch.

[Clunk]

I'm currently running a solenoid jobbie but it's not quite up to the the job..... As in the second battery will only get a good charge when out on a long run..... Will be switching to a dc–dc jobbie once funds permit.

[cgm]

I've had both styles with AGM battery in the rear of the car. AGM definitely lasted longer with the DC-DC charger (I think I was told the Alternator actually charged the AGM at too high a voltage and I think the Calcium ones need higher than the alternator?). I think if you've got a normal wet battery under the bonnet it won't really matter which one you go with. Where's Cuppa, he'll give all the correct technical details! :)

To be honest I do think the type of battery used does influence your decision, so do you know what battery you plan to use and where you intend to locate it?

[sooty_10]

If your aux battery is close to the cranker, connected with decent gauge wire and is not Calcium or whatever technology that requires a higher than normal alternator output then the Projecta is fine and you do not need a DC/DC charger.

The fact that a battery is a deep cycle or not is totally irrelevant to whether it "needs" a DC/DC unit.
DC/DC is only required for technologies that like a higher charge voltage or where there is excessive voltage drop between the charging source and the aux battery like in a caravan or rear mounted battery with small gauge cabling.

Another disadvantage is that you cannot back feed thru most DC/DC units IE use the Aux to start if you have a flat cranker or winch.

Not much more to add to this......

[Bloodyaussie]

Not much more to add to this......

I agree after talking with the guys at Piranha they said the same thing to me as I was looking at dc to dc chargers and was told I did not need one.

[cgm]

I agree after talking with the guys at Piranha they said the same thing to me as I was looking at dc to dc chargers and was told I did not need one.

Although I agree (and I've had two Piranha controllers before - excellent quality and good warranty), advice from them may not be completely independent as I don't think they make a dc to dc charger do they? Both options have their place, but the summary from ET is pretty straight forward.

[cjb]

To many options

[Drewboyaus]

I'm currently running a solenoid jobbie but it's not quite up to the the job..... As in the second battery will only get a good charge when out on a long run..... Will be switching to a dc–dc jobbie once funds permit.

Clunk, you'll find a DCDC charger will actually take longer to charge than using a solenoid under the bonnet as they charge at 20A or something rather than the full monty from the alternator.
What gauge wire is running from the solenoid at the moment? Perhaps you are better off changing that (use battery cables) and buying a new smart solenoid.
Get yourself a smart charger to plug into the 240V at home to keep it topped up from time to time too.

Sent from my iPhone using Forum Runner

[mudski]

Good point Drew. So if your off camping and do flatten the battery, you would need a good drive to charge it up. One thing I like about the red arc sbi12 is the ability to use the aux battery as a cranker just in case your main battery dies. Not that I have actually wired in the switch for it yet....I'm gonna....

[Cuppa]

Scotty, read this http://www.nissanpatrol.com.au/forums/showthread.php?27373-Hodge-s-Dual-Battery-System

[macca]

My old solonoid system was not working as well as it could so a chat with Cuppa and a Redarc BCDC1240 was installed, a 120watt solar panel sourced and we should be sweet now.
It works but I have not had a chance to run through a few cycles of charge discharge that a trip does. Later in the year we are away for 10 days so it should do its magic then.
The battery voltage is 0.2 - 0.4 volts higher now after sitting for a few days, that means the state of charge is a little better.
Happy so far.