View Full Version : Ctek Dual - any experiences

02-11-2013, 20:19
Just wondering if anyone has used the above and if they had any comments.

Am in the final stages of completing my van conversion and was originally very set on a simple split charge system and against the intelligent charger system for cost and ease of repair reasons.

However, i've been reading up on the above, and although its more pricey than a split charge system and still not easily repairable, it does combine battery-battery charging with a MPPT regulator. Now, given that i've got 2 x 100W panels, the fact that it combines both elements is really quite appealing (as is the much more simplified wiring i'll be doing).

So, as i see it:


All in one battery/solar charging
5 stage charging so better for the leisure batteries
MPPT better than the cheap PWM regulators I was planning on


More costly than my originally envisaged split charge + PWM set up
More complex, so if it breaks when i'm in the middle of nowhere I could be in trouble. Saying that, I could always carry a pair of leads (one with a heavy switch in) and just link the VB and LB to charge when driving if the charger broke.

I did initially consider the sterling by the way, (which I know is higher capacity and more 'intelligent') but i'm just not so keen on that as the cost/function trade off is a little too much for me and my budget (purely personal opinion mind)

So anyway - any feedback on the charger appreciated.


02-11-2013, 20:25
I am delighted with the D250S. If it goes wrong, remove connections to alternator and battery, disconnect solar, replace fuse for split charge circuit and off you go.

03-11-2013, 10:29
Have done more reading on it and think i may have to invest.

It says max input of 22v so that should be fine with my panels connected in parallel.

And it is very neat.

03-11-2013, 12:02
I think its a good dc-dc charger and works fine to charge the batterys up to 100%.
But the way i see it i drive to little when i am out with the van, i use about 20-25 ampere every day and i should drive about one hour per day to fill up what i take from the battery and i dont drive i hour per day.
But the day i connect a solar panel i think i will be fine,, if the sun is shining!
I also think about to go for the smartpass ctek sells, just to get around the limitation of 20 ampere the dual has, maybe that can give me some extra ampere in the beginning of the charge-procedure.

My small movie about my Dual, i dont know if you have any use for it but i show it anyway :)


best regards jocke

03-11-2013, 17:32
Cheers for that.

Are there any limitations on what current you can draw from the batteries whilst they are being charged? only ask as reading around a few people seem to have had problems when they've connected 3 way fridges up, though can't quite see why.

03-11-2013, 20:07
No. Battery is just a source of energy. Does not matter if it is being used and charged at the same time.

03-11-2013, 21:32
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03-11-2013, 21:45
I think I'll just stick a manual switch set in for when i mains charge.

I've already got one on the solar panel positive feed and was going to put one between the van battery and charger along with a fuse anyway. So i figure switch em off if/when i plug into the mains, which i don't think will be too often.

I don't think i really need any of the other functions of the smartpass. Not for how I'll be using the van at least

03-11-2013, 21:57
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04-11-2013, 07:29
Just looked into the C-tek D250S (http://www.amazon.co.uk/C-Tek-D250S-Smart-Battery-Charger/dp/B005LBCVL4/ref=wl_it_dp_o_pC_S_nC?ie=UTF8&colid=VBVXW0ASBUP8&coliid=I1F5O20IINCBQO) and it looks the business and I would be able to justify the cost (179.68) for what it does, and does well if my C-tek MXS 3.6 3.8A (http://www.amazon.co.uk/CTEK-Multi-Functional-4-Stage-Battery-Charger/dp/B004TLF4PC/ref=sr_1_2?ie=UTF8&qid=1383517291&sr=8-2&keywords=ctek+charger) is anything to go by.

But after reading the instructions PDF (http://www.ctek.com/Archive/ProductManualPdf/D250S%20DUAL_EN.pdf), to incorporate mains charging it looks like you also have to have the C-tek Smartpass (http://www.amazon.co.uk/C-Tek-Smart-Pass-Battery-Charger/dp/B008TDAKGE/ref=sr_1_1?ie=UTF8&qid=1383517113&sr=8-1&keywords=ctek+smartpass) at another 184.64 plus the instructions show a C-tek M300 25A (http://www.amazon.co.uk/CTEK-M300-Marine-Battery-Charger/dp/B005PV7T4E/ref=sr_1_1?ie=UTF8&qid=1383517127&sr=8-1&keywords=ctek+m300) (253.95) in the circuit. Although a C-tek M200 15A (http://www.amazon.co.uk/CTEK-Marine-Battery-Charger-Conditioner/dp/B002Q54CFG/ref=sr_1_3?ie=UTF8&qid=1383517127&sr=8-3&keywords=ctek+m300) at 132.78 could probably be substituted. I presume my existing 3.8A charger wouldn't cut use

500 is too much for me. Unless I'm not understanding it correctly.

D250S DUAL (http://www.ctek.com/gb/en/chargers/D250S%20DUAL)

I think you are confusing the various bits and pieces. The D250S uses the alternator/solar input to provide multi stage charging. The other bits you refer to are ways of increasing charge current or for specific use eg the marine charger from the alternator input. When on hook up I can use the Sergent output to charge the vehicle battery which in turn provides power to the D250S which means I get multi stage charging so making full use of the units capabilities.

04-11-2013, 08:24
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04-11-2013, 08:47
So the D250S will allow charge from the alternator to the leisure battery and solar to both leisure battery and vehicle battery as it sees fit.
What I'm not sure of is where a mains charger connects to this device so that it will charge both vehicle and leisure battery. I assumed from the instructions diagram that it needed the 'Smartpass' device to do this.

The Smartpass only allows a higher current to be taken from the alternator/vehicle battery and is controlled by the D250S. When on hookup you need a separate charger which in the manual is shown as a M300 but this does not make use of the multistage charging capabilities of the D250S. To overcome this I use the charger in the Sergeant control panel which allows me to charge the starter battery which in turn is connected to the D250S charging the leisure batteries.

04-11-2013, 08:58
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04-11-2013, 09:06
So I could get away with just the D250S and my existing mains charger with a changeover switch to select which battery gets charged from that.
OR, if the mains charger was connected to the starter battery (the alternator terminal on the D250S) would the D250S then change the charge to the leisure battery at some stage? I think that's what you have, yes?

I do like the D250S for what it does and like Hextal am seriously considering this if that is all I need.

Yes and no. Your mains charger would be connected to the starter battery and when charged the D250S would take current to charge the leisure battery. When not on hookup and with solar panels connected to the D250S the unit once charged the leisure battery's will then top up the starter battery. No need for additional switches.
The D250S is a 20A charger so will need a mains charger of that rating to make full use. The Smartpass would allow a higher rated charger to be used. As I said I have found the D250S satisfactory although if I had a larger battery bank the would consider the Smart pass.

04-11-2013, 09:14
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04-11-2013, 10:25
Cheers for that.

Are there any limitations on what current you can draw from the batteries whilst they are being charged? only ask as reading around a few people seem to have had problems when they've connected 3 way fridges up, though can't quite see why.

Well, i dont think there is some limit of what you take out from the battery, its just that the time for charging will be longer the more you use from the battery.
One way to go around this i to do some electrical work to ensure that all the components in the living-area (fridge, ipadchargers etc) is connected with a relay that switches the source between alternator while you drive and the leisure-batterys while you are not driving. If you do so you have all 20 ampere for charging while you drive.

I also think about to connect a bypass for my D250s, i have a big relay but i think i should start with a big switch. If that can tune my system to deliver some more ampere in the initial charge maybe i am home, but a switch also make my system to a hobby.. and it would be better if it just works without me and my memory involved. Maybe its better for me to just go and buy the smartpass so it just work automatic. :)

best regards jocke

04-11-2013, 14:50
That looks like the way I'll go then. Many thanks for that Shortcircuit.

Sorry to hijack the thread Hextal, hopefully you've picked up stuff along the way :)

Ha - you've been asking stuff i'd not thought of - so it's all good with me

04-11-2013, 14:51
Cheers for the help guys.

Now I just need to get permission from 'THE BOSS' and I can get it ordered.:D