Isolator Switch With CTEK's 250S Dual

Ice_Man · May 17, 2012

I recently purchased CTEK's new 250S Dual DC-DC battery charger. I have an Optima Red Top as my main/starter battery and an Optima Yellow Top as my Auxiliary battery. The XJ is being set up as an expedition build and I will be adding a solar panel at some point in time (which the CTEK will be able to handle). My question for your automotive electrical guys, or any one with experience for that matter, is: will I be able to use this unit in conjunction with a battery isolator switch? I would like to be able to switch to my AUX battery to run things like my radio, interior lights, etc when the engine is off, yet have the CTEK handle charging the batteries when the engine is running or there is a solar panel attached. I would also like the option of joining both batteries in the event that I need them for winching. I am still unclear how the internal isolator function works with the 250S Dual. Any input would be appreciated. Thanks.

Heres the link to the CTEK 250S Dual: http://www.ctekbatterychargers.com.au/ctek-d250s-dual.html

And a possible Isolator: http://www.performance4trucks.com/E...c=72&t_s=12&t_pt=5250&t_pl=3486&t_pn=PWP40103

Milford Cubicle II · May 17, 2012

The way I understand the ctek, is that the two batteries are never directly connected in parallel. It does however, automatically isolate one battery. So to answer your question, instead of installing a battery isolator, you probably want to install a battery "joiner." Same part, different name/different purpose. Run the "isolator/joiner" between the positive battery terminals. Most of the time it will be open, allowing the ctek to take care of charging and disconnecting the auxiliary battery. But when you would like to join them for winching, connect the two batteries via the "isolator/joiner." Leaving them in parallel all the time would defeat the purpose of the ctek.

Does that make any sense/answer your question? I'm half asleep...

Ice_Man · May 17, 2012

Milford Cubicle II said:
The way I understand the ctek, is that the two batteries are never directly connected in parallel. It does however, automatically isolate one battery. So to answer your question, instead of installing a battery isolator, you probably want to install a battery "joiner." Same part, different name/different purpose. Run the "isolator/joiner" between the positive battery terminals. Most of the time it will be open, allowing the ctek to take care of charging and disconnecting the auxiliary battery. But when you would like to join them for winching, connect the two batteries via the "isolator/joiner." Leaving them in parallel all the time would defeat the purpose of the ctek.

Does that make any sense/answer your question? I'm half asleep...

That does help. So you’re saying that the CTEK will isolate the "main/starting battery" from the "aux battery" when the engine is off and only use the "aux battery" for power (keeping the "main/starting" fully charged ready to start)? FYI: CTEK seems to make a great product but the manual/instructions are extremely vague. Do you have a recommendation for a specific isolator/joiner that would work well for joining my batteries? I was going to go with the Painless one but thinking that might be more than I need for this setup.

Isolator Switch With CTEK's 250S Dual

Ice_Man

NAXJA Forum User

Milford Cubicle II

NAXJA Forum User

Ice_Man

NAXJA Forum User

Similar threads