Adding CTEK D250s duel charger

[JPR]

I have 2 x 100ah deep cycle batteries that I run on a basic duel battery solenoid. I bought the CTEK duel d250s charger and from my understanding this replaces my solenoid and allows to hook up a solar panel ( minus regulator )
My question is will the panel only charge the deep cycle batteries and should I get the CTEK smartpass also ?
Here's a link to the site http://www.ctek.com/au/en/chargers/D250S DUAL

 

[RustyNav09]

I run the d250s aswell. I have it charging a 120ah battery in the tub. Smartpass is only beneficial if the batteries are in a camper as it draws the power better etc. The d250s is fine by itself for doing what you want it to do. Unless your saying your batteries are in a camper trailer then I would suggest a smartpass aswell.

Also I add a 100ah agm to the battery charger aswell when heading away for the weekend. Both agm but different brands and had no issues

 

[Old.Tony]

If the isolator is between the secondary battery and the cranker, you'll not only charge both by removing the isolator, but you may cause some problems for the D250S.

The D250S takes its input on one side, does its magic and applies that to a battery. If the battery it's applying power to is directly connected to its input, it's going to go loopy.

Ideally, here's what I'd do:

Main battery -> isolator -> cable to rear -> D250S Power 'IN'

Then I'd connect the solar panel to the D250S Solar 'IN'

Connect the output of the D250S to the aux battery in the back ONLY

Connect ALL of the earth (negative) cables together.

This keeps the cranker isolated while the Aux is discharging, so you won't have to worry about the cranker. Alternator and/or solar will provide power to the Aux at up to 20A per hour, so your battery at worst will charge in 4 hours (don't discharge AGM below 20%).

You shouldn't need the Smartpass, for your batteries the D250S should do everything you need.

 

[JPR]

Both batteries are in the ute. so dose it charge all 3 at once or wait until main cranking is charged like a solinoid ?

 

[Old.Tony]

Treat your two deep cycle batteries as a single battery (hooked up in parallel, that's sorta what they are anyway). The output of the D250S connects to both of these. The starter battery cannot be charged by the D250S. You do need an isolator to ensure the starter isn't drained by the D250S.

 

[JPR]

Thanks tony !

 

[joffo81]

I have done what Old Tone suggested and have been happy with battery in tub always being charged to run fridge in the back 24/7.

 

[JPR]

I was thinking though that there is no need for using a regular on the main when using this charger ?

 

[Old.Tony]

Not sure if you are talking about an isolator or a regulator, so I'll look at both.

I'd use an isolator anyway to prevent the C-Tek from drawing anything from the starter battery.

It's my personal opinion - rightly or wrongly - that the starter battery is far more important than the hassle of putting in an isolator of sorts. In my car, I have a 40A breaker followed by a 80A ignition-on relay, so power to the rear can only flow when the ignition is on.

You're right on the money - the C-Tek doesn't need it. Your starter battery does!

As for the solar regulator, don't bother with one. If the panel comes with one, bypass it. This will let the C-Tek work even better.

 

[JPR]

ah I see. I was under the impression the CTEK worked like an isolator also but it seams not. thanks mate.

 

[G-Dubya]

Going by the manual for the CTEK D250S Dual, the CTEK starts charging the auxillary battery when the starter battery reaches 13.1v for 5 seconds (i.e the engine is running) and stops charging when the starter battery reaches 12.8v for 10 seconds (i.e. after the engine has stopped and the voltage has dropped down to this level). The manual also states that when the CTEK is connected to a solar panel, it will charge the auxillary battery to capacity and then start to provide charge the starter battery. If you install an isolator between the starter battery and the CTEK you won't have the ability to charge back to the starter if/when you use a solar panel. A link to the manual is below. Details for the start and stop voltage is on page 23 and infor regarding the charging of both starter and auxillary batteries is on page 9.

http://www.ctek.com/Archive/ProductManualPdf/D250S DUAL_EN.pdf

 

[Old.Tony]

^ That is not only interesting, but impressive. No need for an isolator? Excellent!

If I didn't want to have 240V available, it sounds like the D250S is perfect for me too!

 

[boostin_7]

That's really cool!

 

[WayneD4T]

This link http://www.smartgauge.co.uk/batt_con.html made some interesting points if wiring up multiple batteries for your individual set ups. Maybe it would be useful info for those wanting better performance from their batteries.

WayneD4t

 

[Old.Tony]

That's a very interesting read, Wayne.

Personally I think he didn't quite nail it with the best scenario, because method 4 is unnecessarily complicated (which makes it not as good an option). Method 3 makes things very easy: cut the same length of cable (say 500mm) x as many batteries as you have for both positive and negative, connect one end of each of these together and put battery terminal connectors on the other ends. Then it's just plug and play.

The batteries themselves MUST be identical and preferably from the same manufacturing batch if you're doing this. If not, the batteries will have small variations in stable voltage, internal resistance etc and will discharge themselves simply by being connected and cross-feeding power to each other.

When you see on a battery-powered device (like a portable radio) that you should "never mix batteries of different types" there's a good reason for this. NiCd and NiMH might present similar surface voltages but they have vastly different internal resistances. They will discharge into each other and go flat all on their own. Lead acid batteries are no different - just a lot more expensive!

 

[JPR]

great info thanks! think ill try with the ctec only. my cousin owns a solar install shop so im getting a 260 watt panel from him so should charge them up well up here in NQ !

 

[Old.Tony]

260W in 12V? That's huge. Normally panels over 150W are 24V panels ... make sure you don't get one of those! I'm not sure how well the C-Tek will cope with that much voltage.

 

[JPR]

I'm told it will regulate it from the ctek ? might chase that up again.

 

[Old.Tony]

The C-Tek will regulate it, but on page 20 of the user manual it has a clear warning that the maximum voltage of the panel is 23V, so it will have to be a specific 12V panel. House panels are usually 24V (which have open circuit voltages of 40-50V).

 

[G-Dubya]

Hi all. I got hold of a Ctek MXS 10 battery charger a while back. It comes with a set of alligator clips and a set of 8mm (I think) ring connectors that can be attached directly to your battery. The charger also has a number of different outputs which you select with the mode button on the front of the charger, one of which is 12v supply. That got me thinking that if I connected the ring connectors to the solar input of the D250s Dual, it would mimic being connected to a solar panel when then charger was delivering a 12v supply.

So thats what I did. Checked the voltage at the 2 front batteries and the auxiliary and they were both around 12.6 - 12.8v. I then connected the 12v supply from the MXS 10 to the Solar input of the D250s dual. I then rechecked battery voltages and found all 3 batteries were around 13.4v. So if I ever want to put the batteries in my car on charge, all I need to do is attach the MXS 10 to the D250s Dual solar input via the ring connectors that came with the charger. That's a lot easier than charging all 3 individually.