Dual battery system - DC chargers

[Drjohn11]

Doing my homework on a dual battery system and looking to install either a Ctek 250S Dual or a Redarc BCDC 1220. The issue however with these is the size of the units and being fitted somewhere close to the dual batteries. Has anyone had one of these systems fitted and where are they mounting one of these units in the Challenger?

Thanks

[Heiny]

I would just use a dual battery isolator for an in vehicle dual battery setup, unless you are positioning the battery in the rear of the Challenger, then you could mount a DC-DC charger close to the battery.

I use a CTEK D250S Dual which is installed in my camper trailer right next to the battery, it boosts the charge voltage from the alternator in the Paj back up to 14 plus volts, I also connect a solar panel to the D250S Dual when set up at camp.

bubba

[steveandviv]

I'd like to add on the thought of DC to DC chargers.

While they with out a doubt help if you have voltage drop or one of the newer vehicle that lover the voltage once the start battery is charged or the temp get to high or you must charge you battery to 100% then I would not install a 12 to 12 DC charger. Your alternator is by far then best source and the fastest form of bulk charging and contrary to belief you can get close to 95-97% of charge which to me far out weighs the DC to DC which is limited to 25-40 Amps.

but as stated it depends on what you need. I'm happy to have my Aux batteries running at 95-97% most of the time as I can do smaller runs each day than would be required using a DC to DC. Once I get to a powered site I can then plug the 240 charger to top it to 100% or home.

[Wrex]

See the last few post of this thread. http://www2.pajeroclub.com.au/forum/...ghlight=redarc

I have been running it down here on holidays and are very impressed. Very quick to recharge.

As in the thread above the Ctek is huge in physical size and not recomended for under bonnet applications.

[marquis]

I am about to install a BCDC1220 right behind the passenger side headlight - sick of aux batteries dying after 6 to 18 months of doing bugger all...

Like this

[steveandviv]

I am about to install a BCDC1220 right behind the passenger side headlight - sick of aux batteries dying after 6 to 18 months of doing bugger all...

Like this

Maybe you should use them then, and I don't mean that in a smart arse way. Maybe you should run them at home now and then or what ever you can do to load them up. I get 4 years out of my - flogged batteries. I've posted the reasons I wold get one and they don't suite me but obviously they do you. There is no wrong or right but if you think that the DC charger is going to protect your battery from failure from not being used over years then your wrong - Oh , That's My opinion, from what has worked for me.

And no offence meant at all.

[sharkcaver]

Maybe you should use them then, and I don't mean that in a smart arse way. Maybe you should run them at home now and then or what ever you can do to load them up. I get 4 years out of my - flogged batteries. I've posted the reasons I wold get one and they don't suite me but obviously they do you. There is no wrong or right but if you think that the DC charger is going to protect your battery from failure from not being used over years then your wrong - Oh , That's My opinion, from what has worked for me.

And no offence meant at all.

I agree. I would be looking into why the bats failed before lashing out on a dc-dc charger. I doubt its got anything to do with the charging regime (unless it was poorly set up or there was none to start with), therefore I cant see how a dc-dc charger is going to make a difference in that respect. Your starter battery should have had the same charge regime as your aux but it sounds like only your aux's failed. Why is it so? And the above is meant to help but looks like the purchase of the dc-dc charger is post tense so the above is of no use now.

Shane.

[marquis]

Traveling in 2007 cont around Aus the aux battery lasted 7 months - died from overcharging (running fridge and lights every day). It was replaced with a trojan in wa - another 12mths later it died (mostly runnin the fridge most days)

This time I am limiting charge rate and being able to have float voltages - I am hoping the aux battery will last longer - particularly in the hotter areas (the redarc reduces current output over 55c )

WA on the last trip the hottest was 48c driving into marble bar in September

Note most batteries are not designed to be charged at 14.5v continuously day in day out - something that occurs when you are touring, being able to float back to 13.3v is a good thing.

[sharkcaver]

Traveling in 2007 cont around Aus the aux battery lasted 7 months - died from overcharging (running fridge and lights every day). It was replaced with a trojan in wa - another 12mths later it died (mostly runnin the fridge most days)

This time I am limiting charge rate and being able to have float voltages - I am hoping the aux battery will last longer - particularly in the hotter areas (the redarc reduces current output over 55c )

WA on the last trip the hottest was 48c driving into marble bar in September

Note most batteries are not designed to be charged at 14.5v continuously day in day out - something that occurs when you are touring, being able to float back to 13.3v is a good thing.

I note in your sig your running agm. Agm's do prefer a lower bulking voltage and dont like heat. Having said that no battery really likes the degree of heat you mention. You could almost double that ambient under the bonnet in those conditions. They are the extremist of extremes you mention.

You say the original battery died from over charging. Maybe, I cant answer that. Maybe it was just due to the combined heavy cycling and the high heat it was put through.

The battery might sit at 14.5v continuously when alternator charging, but when charged it will be accepting bugger all current. Its not like your forcing 10 or more amps at 14.5V through it, boiling the electrolyte and eroding the plates away.

From what you describe above, even with a dc-dc charger, the bulk of your batteries time when charging will be spent in absorption (IE 14.5V+ at reducing current). For the majority of your charge time you have gained nothing whatsoever over an alternator charge apart from maybe a reduced current. The float will be an advantage, the extent of which is debatable, but from your usage as described above (which I note contradicts your initial post of the battery doing bugger all), I don't think you'll gain any note worthy advantage to longevity. I hope you can prove me wrong on this.

Ever considered a wet cell? Cheaper to purchase, higher voltage and temperature tolerance, maybe more prone to failure in the rough. Saves the expense of a dc-dc unit and arguably more reliable to boot.

Shane.

[Wrex]

I have been running my Fridge and 300w invertor for laptops for the last 2 weeks and am very happy with the recharge times and overall performance from the redarc (above Pics)