Battery charger setup. Solar, 240v and alternator

[BarneyMaroon]

I saw the great article on camper trailer set up with the red arc on this site. The model seems to handle solar, alternators and 240 volt. I presume the latter is via a 240 volt to 12 volt transformer. My question is what type does it need to be. I know there are. Expensive jobs, but I wondered, since the red arc does all the controlling, any transformer that can handle a decent charge would be ok. Basically I am trying to add 240 volts without adding 300 to the setup. Cheers, Barney

[robcaz]

Hi Barney,

What size battery or batteries do you have in your camper???

That would be Rod Luhrs writeup of the Redarc BMS1215 http://www.campertrailers.org/smart_start.htm

The Redarc BMS1215 is a complete battery management solution, charging your camper trailer battery via a 240volt 15amp 5 stage charger, a 12volt DC to DC 20amp 3 stage charger, a maximum power point tracking solar regulator, plus a battery monitor. Rod's article is with the 20amp 3 stage solar regulator before Redarc's MPPT update.

The Redarc BCDC1225 is a 25amp 3 stage DC to DC charger & also a MPPT solar regulator. You will find my install article http://www.campertrailers.org/bcdc1225_install.htm You then require a 240volt charger to maintain your battery at home. Reliable brands include Ctek & Projecta.

A rule of thumb to charger size is 10% to 15% the capacity of your battery, so if you have a 100 amp hour battery for example you will need a 240volt multi stage charger that will put out 10 to 15 amps.

While not essential, you will also need to add a battery monitor to the cost to match what you get in the BMS1215 package if building from different components & mixing brands. I have just installed a Enerdrive Elite monitor http://www.campertrailers.org/enerdrive_elite.htm

Have a Google around & you will find the Redarc BMS1215 for under $1,000.

If building a system from different components & brands you could put together a Projecta or Ctek 240volt charger, a Ctek D250S or Redarc BCDC1225 together for around $600, plus another $220 for a NASA BM compact battery monitor.

Please feel free to drop me a PM or email if you would like where to find the best prices.

[BarneyMaroon]

Thanks for the information. I have two 110Ah on the 2nd hand 2004 Trackabout Safari I bought. They were charged with the CTEK 25000 240v job, and that worked for about four hours after I plugged it in before dying (no LED lights, bricked as far as I can tell). I cannot find anywhere in the manual saying you can only run it for four hours! Either that or I bought it right at the end of its life (its 3 year old, out of warranty).

The BMS1215 is more than I can afford (still have panels, bull bar, roof racks and outback tyres to fit to Prado - ouch)

I googled the Ctek D250S after reading your post. Looks good. That goes for $220 which is closer to my budget. I want to run 180W solar into that, and get some heavy wire run to an Anderson plug at the back of my Prado for a Waeco and to charge my two CT 110Ah. I note some people online run two lines, one for each application. I would have thought that one (red+black) 8 B&S 12v wire would be sufficent. Happy to be advised otherwise.

I do note that several people online have stuck a high wattage 240v to 13.5v (25 Amp @ 13.5v) transformer into the D250S for home-charging ($125). They claim the Ctek unit just sees it as a solar panel. I can't think of anything wrong with this setup, (so $220+$125 does the job). Again (very) happy to be advised it is nuts - I am a novice. I don't know what it would do if I left it on for a week however!

I do love the idea of having a meter so I can see its all working as well.

Again, thanks for info and awesome site.

[robcaz]

Hi Barney,

I do not know if the 240volt Ctek's have an internal fuse, but it could be something as simple as that. I may be worth having someone look at it, but could end up costing you as much as a new one to find out it is not worth repairing???

It is standard practice to run separate cables to your camper trailer batteries via an Anderson connector & then another to the fridge in the rear of your vehicle.

You will find 6mm twin core sheathed auto cable (4mm sq) is more than enough to supply power to the Waeco in the rear of your vehicle. 6B&S (16mm sq) is the standard cable size for a run from the engine bay to the camper trailer batteries & a need fit into a 50amp Anderson. An overview of cable sizes can be seen on Collyn Rivers page

Redarc's cable size calculator makes it very easy to find the right size cable to suit a particular application

For great prices on 6mm & 6B&S twin core sheathed cable check autoelecau's ebay shop.

I have not heard of a transformer being connected to the Ctek D250S.

[KevKathQld]

I have heard some retailers have dropped the Ctek 240V charger range due to a high number of failures.
I have two of them, 15A and 7A and had no issues with either but mine go back maybe 5 years.
I don't leave them connected for weeks on end though as they have no AGM battery setting (all automatic) and have a higher float current than my Projector 240V 25A charger I have in the camper, which worries me. I like to be able to switch the battery type manually. Just personal preference.

[BarneyMaroon]

Interesting about the 240v Ctek. Glad to hear I didn't do something very silly which caused it to fail.

[01_Rod]

The redarc BMS is a great unit.. And a great system that does everything for you..

If the CTEC unit is only just out of warranty (3months) try sending it back to CTEC
And get them to check it out... You never know they might replace it or fix it for you?.

Rod

[Ovaworked]

Sorry for the hijack
but could the battery maintenance at home be taken care of by a solar panel left connected and bolted to a toolbox using either the bms1215 or the bcdc1225?
Would this be a safer option?
I'm a bit wary when it comes to leaving 240 volt chargers connected long term as I've had a battery explode on me previously?

[BarneyMaroon]

Sorry for the hijack
but could the battery maintenance at home be taken care of by a solar panel left connected and bolted to a toolbox using either the bms1215 or the bcdc1225?
Would this be a safer option?
I'm a bit wary when it comes to leaving 240 volt chargers connected long term as I've had a battery explode on me previously?

Yep, that is what my auto-electrician suggested. He also confirmed my ctek had been bricked. My problem is that my northern aspect is in my front yard and someone might know the panels are worth $300. I will try chaining them up and be trusting. I might use a 240 volt to 14v transformer for short term caravan park charging if I need to.

[Ovaworked]

My camper is in the back yard so hopefully no one will be that stupid

I'm still trying to finalize my set up but so far I'm thinking
2 x 120A agm batteries
200 watts of Solar panels
Redarc Bcdc1225
600 watt inverter
And like you 240 volt charger for park stays

My ideal set up needs to do all the above with out taking up too much space but I'm not aware of any other configuration or products that would accomplish this more economically space wise with out requiring a kidney to be sold