Ctek D250s versus Redarc

[Peeeeda]

I want to get the Ctek to maximise the amps available from my pissy 55amp aux battery and also hook up the solar to it but I'm not sure if I keep the Redarc SBi12 voltage sensitive relay or does the ctek replace it completely. Been searching for ages but still not sure. Any info apreciated. Ta

 

[4.8GU]

It replaces it mate. Unit senses 12.8v and isolates the main from the aux.

I have one in my ute and it is the best dual battery system I have had.
Seems to keep the aux topped up way more than normal solinoid type.

I have a 100ah agm so I know it is charging it correctly and giving me maximum battery life and use time.

 

[RustyNav09]

Opening an old thread. I have searched but not yet found the info I need.

I am wanting to remove my battery isolator and put in a charger that will bring my battery to its maximum charge. I have looked at the redarc bcdc charger 1220 model and also the ctek d250s dual. I can get them for around the $300 mark. I am going to use solar panels and the campsite to keep thyroid battery trickle charging.

Any ideas and peoples thoughts?

Rusty

 

[4.0lt]

I have the standard Redarc under the bonnet to charge the 100amp aux in the tray.My aux is on charge constantly via a ctek 5 charger as both fridges are running always as beer fridge..Recently bought a PV contoller from Jaycar to replace the regulator on a 100watt solar for charging while in bush, this was putting in 14.1 volts at 4.5 amps into the aux.

 

[Old.Tony]

My understanding is that the C-Tek Dual allows both sources (alternator and solar) and manages the battery correctly using a 6-stage charge at a higher voltage than your alternator puts out (it boosts the voltage).

This means that it will fully charge the battery from either alternator or solar. The Redarc unit boosts the voltage also, so it will fully charge the aux battery, but it doesn't take a solar input and it's a 3-stage charger - which is enough for most purposes, but the C-Tek does stand out as a better alternative.

 

[RustyNav09]

The ctek unit is pretty dam big. Where am I meant to put something of such size?

 

[Old.Tony]

I'd put it close to the aux battery, to minimise the length of the cables from the unit to the aux battery - maximising the unit's accuracy. Run heavy cables from the front (via a decent-sized fuse - like 40A) to the tub to minimise losses and fire risk.

 

[joe2006]

Just in case an assumption is wrong, these things are not suitable for LiFeP04 (Li) batteries are they?

 

[Old.Tony]

I doubt it, Joe. Lithium batteries are a new technology and the bloody things are finicky as all hell - it's rather annoying when you get it wrong and they overheat and die, because they're dear as poison. While I was reading both Redarc and C-Tek web pages (about these particular chargers) I saw no mention to say they're suitable for Lithium batteries.

 

[sparra04]

the redarc bcdc 1240 is 40 amp and has mppt solar regulator built in
i would have got the 1240 but there a big unit, ime happy with the 1220 sofar and i use a portable panel with built in reg when i need to
i recently installed the ctec d250s (20 amp) in a mates camper
its got 2 x 100 a/h agm's and a huge solar panel on roof,280 watt i think?
he is running 1 fridge and 1 freezer plus lights and inverter
there off into the desert for 9 weeks so ile have some feedback soon on its performance

 

[RustyNav09]

Thinking of going the ctek. They are Sweden made so pretty much top quality. Gonna mount it right beside the aux agm battery.

If I do this do I now need to change my 100amp anl fuse to 40amp?

 

[Old.Tony]

Your fuse should be rated marginally above the expected current draw on the cable. If the D250S charges at 20A, it probably draws (peak) around 25A so I'd use a 30A fuse, or better yet a 30A thermal breaker.

That's a little different to Waeco's idea, come to think of it. They thought it would be neat to ultra-protect their compressors, and in our fridge installed a 3A fuse. The fridge draws 7.5A (peak) and 5.5-6.5A when running.

This is nuts. The fuse becomes a heater element, increases its resistance by a huge factor, causing a voltage drop on the other side - triggering the fridge to shut down.

I've got to change it to a 10A - but I have to pull the bloody thing out to do it, because it's tucked away where you can't get to it.

The moral: don't under-specify your fuse.

 

[reel-sensation]

Hi Tony

I think there is a fuse in the lighter socket plug of the Waeco cord too.

Alan

 

[RustyNav09]

Hmmm hoping I can find some anl fuses small enough. I don't really wanna remove the fuse holders I have.

 

[RustyNav09]

after much further searching i am now confused on how this should be installed. can i keep the redarc isolator installed and run a 40amp fuse between it and the ctek charger then one between the ctek and deep cycle?

 

[sparra04]

the ctec (and redarc) monitor the cranking batt and wont start to charge your aux batt till it sees a certain voltage from the cranking batt
you need to remove the redarc isolator and connect ctek to cranking batt with a 40 amp fuse
in my opinion if you have a long cable run,ie tub or trailer to your ctec or redarc you should use 100 amp fuse at either end of cable in case of cable damage then put a 40 amp circuit breaker to dc/dc charger

 

[RustyNav09]

sparra - so if my battery system atm goes something like this(see below)

start battery>100amp fuse>redarc isolator>6b&s cable to tub>100amp fuse>100ah agm battery

if i was to this (see below)

start battery>100amp fuse>40ampauto reset breaker>6b&s cable to tub>100amp fuse>ctekS250S dual>100ah agm battery

would this be correct? or what else do i need to add in? i would obviously need to add in a circuit breaker after the agm for the fuse block.

Rustynav

 

[Old.Tony]

Hi Tony

I think there is a fuse in the lighter socket plug of the Waeco cord too.

Alan

I should have been clearer with what my Waeco is - it's a CR140 fridge, upright about the size of a bar fridge. Fix-mounted in the caravan, so definitely no lighter socket making things easy for me!

 

[Old.Tony]

sparra - so if my battery system atm goes something like this(see below)

start battery>100amp fuse>redarc isolator>6b&s cable to tub>100amp fuse>100ah agm battery

if i was to this (see below)

start battery>100amp fuse>40ampauto reset breaker>6b&s cable to tub>100amp fuse>ctekS250S dual>100ah agm battery

would this be correct? or what else do i need to add in? i would obviously need to add in a circuit breaker after the agm for the fuse block.

Rustynav

I'd dump the 100A fuses for starters.

The first 100A fuse isn't protecting anything, the breaker will trip long before the 100A fuse gets warm. The 40A breaker will do a sterling job of protecting the vehicle and battery from any problem with the cable run.

The second 100A fuse doesn't have anything to protect because there's no power source between it and the cable run - just the C-Tek charger, and you're on its input side - so just take it out of the equation (more items = more problems).

The C-Tek charger will manage power to the battery just fine, so no need for a fuse there.

You need to make sure that every device connected to the battery is fused, or YOU provide the fuse (eg a lighter socket needs a 20A fuse inbetween it and the battery).

So your setup would go like this:

Starterbattery -> breaker -> cable to tub -> C-Tek -> aux battery -> fused outputs

Sound ok?

 

[RustyNav09]

Thanks tony. I think I may get the ctek unit. Gotta order the auto breaker. Off the aux battery I have a baintech 6way fuse block. So everything is fused