CTEK 25000 -vs- D250S Dual + SmartPass

I'm been reading the electrical threads here and have decided to go with a CTEK charger for battery to battery charging. There seem to be two main setups that people go with.

1. CTEK25000 - about $230
2. CTEK D250S Dual + Smartpass - about $440 together

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I'm going to have a 200w solar setup and 250ah Lifeline AGM battery. I'll be moving around a lot, so want to take advantage of charging from car battery.

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- The CTEK "D250S Dual has a built-in Maximum Power Point Tracker (MPPT)". That sounds great, so I can save money on the MPPT. Is that correct? Are there any major tradeoffs with going with the Dual instead of a separate MPPT?

- So if I go with the CTEK25000 I'll not only have to get a separate MPPT, but what exactly am I missing out on from not having the Smartpass in the system? What else would I have to buy if I go with the CTEK25000 setup?


I half understand these setups and any help clarifying would be much appreciated.