Comparing CTEK D250S and SmartPass vs Redarc DC-DC Charger

Question

Question:

I had a few last questions Iwanted to get clarity on: 1 Tthe Redarc will put out 40A while the CTEK2505S with the Smart Pass will allow 80A SmartPass or 100A sum of two CTEK parts? 2 I can charge one or two batteries more quickly with the CTEK with SmartPass vs the Redarc? Just wanted to confirm difference and maybe this justifies the price difference. 3 I got from a previous question I asked that the maximum input on the Solar side for the CTEk was 25A. If I attach 3 100W solar panels at 12V or 13V, Im ok on the CTEK at about 25 or 23 amps. I wanted to know what the input limit was on the Redarc. I looked at the manual and all it says is that I can have an input voltage of 9-23 or 24V, but not readout on the max input amps allowed. 4 You previously indicated that you preferred the redarc over the CTEK2505S, and on its own, I get that redarcs specs are better, but if you add the CTEKSmart Pass to the mix, it would appear that the CTEK has more output than the Redarc if Im considering having 2 spare batteries to charge with 2 or 3 solar panels. Wanted to get your final thoughts here. Thanks again for your help

asked by: Frank

0

Expert Reply:

I reached out to my contact at CTEK and the CTEK D250S Dual Battery Charger 12V- 20a, 5 step, Heavy Duty CTEK40186 (discontinued) does utilize the Maximum Power Point Tracker (MPPT) as well. When partnered with the (discontinued) Smartpass CTEK56676 you will be able to run your fridge/freezer as you stated. The Redarc In-Vehicle BCDC Battery Charger # 331-BCDC1240D will also be able to accomplish this so it is a better option for this application. You will also need the fuse kit # 331-FK60 for this installation.

expert reply by: Jason S

0

Frank

2/6/2018

I had a few last questions Iwanted to get clarity on: 1 Tthe Redarc will put out 40A while the CTEK2505S with the Smart Pass will allow 80A SmartPass or 100A sum of two CTEK parts? 2 I can charge one or two batteries more quickly with the CTEK with SmartPass vs the Redarc? Just wanted to confirm difference and maybe this justifies the price difference. 3 I got from a previous question I asked that the maximum input on the Solar side for the CTEk was 25A. If I attach 3 100W solar panels at 12V or 13V, Im ok on the CTEK at about 25 or 23 amps. I wanted to know what the input limit was on the Redarc. I looked at the manual and all it says is that I can have an input voltage of 9-23 or 24V, but not readout on the max input amps allowed. 4 You previously indicated that you preferred the redarc over the CTEK2505S, and on its own, I get that redarcs specs are better, but if you add the CTEKSmart Pass to the mix, it would appear that the CTEK has more output than the Redarc if Im considering having 2 spare batteries to charge with 2 or 3 solar panels. Wanted to get your final thoughts here. Thanks again for your help

Reply

Jason S.

2/6/2018

Let me take these one by one: 1- The BCDC1240D can provide a continuous 40A charge if the auxiliary battery requires it. The smart pass will link the 2 batteries together and allow the alternator current to charge the auxiliary battery when required. There is no current limiting or control when the batteries are joined, with variables such as cable size, alternator size, battery state of charge, voltage drop etc. determining the current the battery will receive. Without monitoring the current, it is hard to say how long it will take the batteries to charge using this approach. All I can say is that either will charge efficiently. If you want to wire the batteries directly to the alternator you can use # 331-SBI12 and that would allow you to switch it manually when required. 2- It is difficult to say how quickly the batteries will charge using the direct battery link method but a BCDC1240D can provide the full 40A to the battery continuously meaning the batteries will charge quickly and safely. The CTEK combination may be faster (if you have the discontinued smartpass), but it is unknown as we haven't monitored them to compare. 3- There is no wattage limit to the input of the RedArc product. The panels just need to be within the Voltage range specified. Even though a 600W panel and a 1,000W panel both will give you the full 40A charge, the amp hours of charge into your battery bank may be different. So a 1,000W panel will still give you more amp hours of charge each day than a 600W panel. 4- This gets back into the unknown charge time and the variables listed above. The CTEK System may have more output. Since you are looking at multiple solar panels, the RedArc BCDC uses Green Power Priority. This is the priority given to a solar input when charging an auxiliary battery in your vehicle. For example, if a solar power input is available the maximum available solar power will be used before topping up the output charge current from another power source. Priority is given to the solar input then to AC Mains power (where applicable), then to DC Vehicle Power, the advantage of this is that it places less load on the alternator. The D250S does the opposite as the solar panel adjusts to the alternator, giving the alternator priority. This difference comes down to preference.

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