09 D22 dual battery setup

[Old.Tony]

I wouldn't put that long a cable between a mains charger and the battery it's trying to care for. I'd also NEVER put mismatched batteries on the one charger at the same time, so if your aux battery in the tub is different to the battery in the camper, just use two chargers.

That's how I have mine. Inverter + 6A Jaycar charger in the tub for the 100Ah Gel, inverter + C-Tek 7A charger in the caravan for the 160Ah Optima AGM.

 

[rexxie]

Thanks Tony, i guess that was the answer i wasnt hoping for lol Mismatched batteries wont be an issue as I am buying both together next week but I did think that I was going to need two battery charger setups. I have to wonder how long you can get away with running a deep cycle battery in the car without a battery charger and just relying on the alternator? I know thats how my ex had it setup in the patrol we had and it seemed to keep the waeco running fine.

 

[Old.Tony]

If the deep cycle is a gel and you're getting more than 14.1V in the tub you'll kill the battery - gels hate too high a voltage, and too high a charge rate too. You can discharge gels at a reasonable rate, because discharging doesn't cause fizzing, but high charge rates cause hydrogen and oxygen to be separated from the water in the gel, which causes bubbling and since it's a gel, the bubbles never go away = dead battery.

If it's a normal flood cell or AGM battery in the tub, you'll be fine - when you work out your capacity figures, don't count on that battery being 100% full, but as long as the battery is isolated from the starter and the cable is fused on both ends it shouldn't be a worry at all.

 

[rexxie]

Cheers for that Tony, i get lost a bit when it comes to how batteries work but was planning on getting an AGM one as i had read a bit aboug gel so decided not to get one of those. Yes was going to put an isolater inbetween the starter and deep cycle in the engine bay....when you say fused at each end, is that the same as a circuit breaker? The diagrams i had looked at show using a circuit breaker but the fuses werent needed until i started putting my 12v outlets in.

 

[Old.Tony]

Either a fuse or a circuit breaker will do.

The goal is to protect the car. A battery sitting in the tub connected to cables that run through to the front will cause a lot of damage when the cable gets shunted by a stick and shorts out. Works the same for the connection from the starter battery. Those fuses are all about protecting the car, not the devices.

The fuses in the outlets and/or the cables heading to the devices are supposed to protect the devices, but also protect from a cable short as well (although that's less likely to happen).

 

[rexxie]

Gotcha Thanks for all that!

 

[Nathan 2005 D22]

I would fit the charger to the camper as you would be able to maintain the camper while not in use without allot of effort. Yes it would charge your car via the Anderson plug, but there would be a voltage drop on your furthest battery and if your running a VSR? the main car battery won't charge as the VSR wouldn't engage in reverse, assuming the Anderson plug is connected to your 2nd battery. Also if you decided to charge more than 1 battery off one charger you should consider a diode splitter to keep them separated. Also consider a solar setup they do work well for the fridges, water pumps and lighting, although it wouldn't compensate for the inverter usage.

 

[Flynndog]

So I just want to get this correct; the CTEK D250S will provide my dual battery system needs and replace my crap TJM DBS systems with no worries?

 

[sparra04]

So I just want to get this correct; the CTEK D250S will provide my dual battery system needs and replace my crap TJM DBS systems with no worries?

the ctek is a brilliant system
i fitted one to a mates camper running 2x 100a/h batts plus 180 watt solar
he has just returned from 8 wks in the simpson running a fridge and freezer and all accesories with no dramas
highly reccomended system
i personally use redarc bc/dc cause its a smaller unit and it works fine charging 2x aux batts
dc to dc is the way to go

 

[RustyNav09]

I have the ctek unit. Love it. It has replaced my redarc unit and it keeps the battery st 100%. I also connect solar to it when I'm setting camp

 

[Bucktruck]

My dad allways said the "kiss" principal and I reckon he was on to something so I'm wacking an extra battery in with two switches so I can have either both battery's on off or a combination of either one because a mate of mine bought a 300 dollar system and it had a major downfall of draining one battery when the car was off but as soon as you turn the car on to start it the next morning it would bridge the battery's again so half the power of your charged battery would go into the flat battery and I'm not keen on that so I thought my system would be a good idea? What do you guys think?

 

[bods]

My dad allways said the "kiss" principal and I reckon he was on to something so I'm wacking an extra battery in with two switches so I can have either both battery's on off or a combination of either one because a mate of mine bought a 300 dollar system and it had a major downfall of draining one battery when the car was off but as soon as you turn the car on to start it the next morning it would bridge the battery's again so half the power of your charged battery would go into the flat battery and I'm not keen on that so I thought my system would be a good idea? What do you guys think?

that's where the "smart" relays, or voltage sensing relays come in. they don't bridge the batteries until the main battery reaches a certain voltage. so it won't actually link them until the alternator starts charging the main battery. that way you don't risk bridging a flat battery to a full charged one. they also cut off below a certain voltage, so they are purely separate systems.

the other way people have mentioned by using chargers, etc the batteries aren't connected together at all so there is absolutely no risk of draining your starter batter.

your way can still "fail" in that you may still forget to turn one on or off and end up with a flat cranking battery or a flat aux battery when you need them. a "smart" relay overcomes all those problems automatically and they're not that expensive...

 

[Old.Tony]

+1 on Bod's advice. Replace the switch with an isolator and your manual switch is now automatic, caring for your starter battery just like you would.

 

[Jimbob]

G'day guy's,

I am running a dual battery system in my 04 d22 with the house battery in the tray.
I have REDARC BCDC 1240 dual battery management system and running two Engel’s. One is an 18 year old 40ltr and the other a newer 32ltr.
I am in the process of looking for a way to maintain charge for my 100 Ah AGM deep cycle house battery for extended periods of time.
I have been told that I will need to invest in another 100 Ah battery as well as a set of 120 watt portable solar panels.
I am not overly keen on purchasing and installing another battery in the tray and have been looking at solar panels above 120 watts.
Can anyone please give me suggestions for the best set up to maintain charge for extended periods of time?

 

[Old.Tony]

Jimbob, those Engels are drawing what, 4A combined? Let's say that's 4x12 = 48A a day.

With a 120W (say 8A) panel in the middle of winter you'll recover at least 5hrsx8A = 40A per day. You'll scrape more than that if your panels are shade tolerant (monocrystalline).

Panels larger than 120W are typically 24V. Using a DC-DC converter will lose some power (all circuitry uses SOME power) but with a 220W panel (say 200) you'll be recovering about 15A per hour = 75A during the day. The price is a DC-DC converter that takes 24V and creates 12V. Personally I'd consider that unreliable and would pursue the 2x120W monocrystalline panel idea providing 16A (=80A/day).

Not sure you'd need the extra battery. AGMs can generally be drawn to 20% of their capacity before suffering badly.

 

[Jason]

I'd also make sure the older Engel is well serviced (if you haven't already). Older equipment can run less efficiently and things like being low on gas can produce short cycling. All can contribute to more power use.

 

[Jimbob]

Thanks Tony and Jason, I will look into it.
The 2x120W Panels may be the way to go.

 

[wes570]

i need HELP plz i have a 03 model str zd30 and i want to put a daul battery in under the bonet. can some one tell me what size wiers do i need, what is a good isulator to use, and what else do i need? i wouldent mined having a option to conecct a solar later on down the trak.

 

[wes570]

Has anyone got a diagram how a dual battery should be wired up?

 

[wes570]

I have have been given a battery to do my dual but I need help though can anyone help me