CTEK SMARTPASS 120S and 250SE DC to DC charger basic features and install information

Ragman · Apr 6, 2024

Logsplitter said:
So if the VOC is too high for the Ctek 250SE then maybe it’s easier to use folding/suitcase style solar panels with inbuilt mppt controllers as I do. This would then make it easier to move between vehicles as you require

Yep, had I not misread my current panel spec all would be good. I have installed the 250SE so will grab another set of panels that work for both my applications and figure out what to do with the others.

Ragman · Apr 6, 2024

globalgregors said:
Noting that the solar blanket mentioned is also available bundled with a mppt controller.
This is what we were using prior to installing the D250SE, I was clamping it onto the auxiliary battery and the Smartpass was working things out from there.

Had I been more attentive I might have gone that direction and connected them via the jump start connections under the hood. All in all this has been a great learning experience.

The knowledge on this forum is so helpful and such a great resource.

globalgregors · Apr 6, 2024

Ragman said:
Had I been more attentive I might have gone that direction and connected them via the jump start connections under the hood. All in all this has been a great learning experience.

The knowledge on this forum is so helpful and such a great resource.

Yes, agreed - the owner community even beyond the forum is a good one.
Will be interested to see where you land with your setup.

Ragman · Apr 6, 2024

globalgregors said:
Yes, agreed - the owner community even beyond the forum is a good one.
Will be interested to see where you land with your setup.

My 250SE install video is coming out tomorrow morning. I expect I will go with the Eco Flow 220w portable panels as they have 21.5 VOC and retain the MC4 couplers which match my other gear.

IG_in_AZ · Apr 6, 2024

Having read the last two pages of this thread regarding things I didn't and still maybe don't completely understand, and trying to reconcile this new knowledge (VOC, specifically) with the things I bought because, hey, solar is cool! (although I probably don't need it for my non-overlanding 4x4 use of the Grenadier.... I have the CTEK D250SE because everyone else was buying them, and I also needed solar panels, right? So, I also bought this last year:

https://www.renogy.com/200-watt-12-volt-solar-starter-kit-w-mppt-charge-controller/ with the 20A controller

I'm thinking I have way too much, meaning the basic solar system I bought, having the 20A mppt controller and the CTEK D250SE is redundant? Or am I just confused. Well, obviously, I'm confused.

So, it appears that I can't even use the panels with the CTEK because their VOC is too high:

So, do I use the MPPT and hook it to the CTEK, or sell the CTEK and mount the Renogy MPPT in the Grenadier? Or, just sell it all and not worry with it? I also have a Renogy 2KW pure sine invertor, which was the reason for the solar kit.

I'm open to whatever help and advice you can provide.

Thanks!

globalgregors · Apr 6, 2024

IG_in_AZ said:
Having read the last two pages of this thread regarding things I didn't and still maybe don't completely understand, and trying to reconcile this new knowledge (VOC, specifically) with the things I bought because, hey, solar is cool! (although I probably don't need it for my non-overlanding 4x4 use of the Grenadier.... I have the CTEK D250SE because everyone else was buying them, and I also needed solar panels, right? So, I also bought this last year:

https://www.renogy.com/200-watt-12-volt-solar-starter-kit-w-mppt-charge-controller/ with the 20A controller

I'm thinking I have way too much, meaning the basic solar system I bought, having the 20A mppt controller and the CTEK D250SE is redundant? Or am I just confused. Well, obviously, I'm confused.

So, it appears that I can't even use the panels with the CTEK because their VOC is too high:
View attachment 7851832

So, do I use the MPPT and hook it to the CTEK, or sell the CTEK and mount the Renogy MPPT in the Grenadier? Or, just sell it all and not worry with it? I also have a Renogy 2KW pure sine invertor, which was the reason for the solar kit.

I'm open to whatever help and advice you can provide.

Thanks!

So yes, those panels are out of spec for the D250SE.

Given you’ve already purchased what you have, if I were you I’d install the Renogy MPPT controller and run it direct to whichever battery you are running the inverter from (presuming the inverter is your largest consumer?).

I’d leave the D250SE as is, this will offer some redundancy or indeed an option to add additional solar if you find you’re consuming faster than you’re producing (which may be down to your local sun as much as energy use).

Our use case may be a bit different as we prep for remote use and diverse climates: I like to have a Plan B.

2000W is quite a bit of inverter… I wonder are you using an induction cooktop?

Ragman · Apr 6, 2024

I know when I bought the 250SE it was for solar but even if you are not using it as your primary solar the unit in combo with the Smartpass it creates a "better" DC-DC charger from my understanding.

If I knew then what I know now (measured in ounces, not quarts!) I would have seriously looked at the Redarc set up with the included MPPT that I could simply have connected to the jump charge posts when needed, but I am happy with the outcome of my install now that I have correctly matched panels with the 250SE. I am not using a permanent installation of panels because I use different vehicles so I move the panels from one to another and use them on my Bluetti portable battery pack.

Ex-defender driver · Apr 6, 2024

IG_in_AZ said:
Having read the last two pages of this thread regarding things I didn't and still maybe don't completely understand, and trying to reconcile this new knowledge (VOC, specifically) with the things I bought because, hey, solar is cool! (although I probably don't need it for my non-overlanding 4x4 use of the Grenadier.... I have the CTEK D250SE because everyone else was buying them, and I also needed solar panels, right? So, I also bought this last year:

https://www.renogy.com/200-watt-12-volt-solar-starter-kit-w-mppt-charge-controller/ with the 20A controller

I'm thinking I have way too much, meaning the basic solar system I bought, having the 20A mppt controller and the CTEK D250SE is redundant? Or am I just confused. Well, obviously, I'm confused.

So, it appears that I can't even use the panels with the CTEK because their VOC is too high:
View attachment 7851832

So, do I use the MPPT and hook it to the CTEK, or sell the CTEK and mount the Renogy MPPT in the Grenadier? Or, just sell it all and not worry with it? I also have a Renogy 2KW pure sine invertor, which was the reason for the solar kit.

I'm open to whatever help and advice you can provide.

Thanks!

They are great panels because of the flexibility - I have used for many years with no problem but i got the 100W panel which has an open circuit voltage less than 23V. They are not expensive.

K1LL3M · Apr 9, 2024

In case it helps others looking for options (mostly in Aus sorry.)

The HardKorr 300w Solar Blanket works really well. I have used this on a couple camping trips watching it reach up to 270watts and if 120ish in overcast conditions. It's expensive but search around, I managed to get it of a dealers ebay site with a $50 ebay credit deal paying aboit 520 for. Its impressed more than I thought it could.

Currently looking at solar panels for the roof to install 24/7 to keep fridge in car all the time, with blank for added juice camping (panels can run parallel just not series ie more amps, same volts)

Current top options in order

Tuff Terrain 200w
I like this panel because it's 200w and only 22m thick

Kickass 170w (if you want more they also have a 350w panel that will work but it's larger and heavier obviously, their 250w is out of spec.)

Atem /Sunyee have an Older 200w panel with under 23v, it's still on their website but always sold out (dont be confused by the bifacial or flex panel, both are out of spec

Knysna · Apr 10, 2024

Just finished my installation and tested with my solar blanket and functioning correctly I did need to modify the Black Sheep bracket and move my D250SE closer to the Smartpass because it rubbed on my seat supports and the battery temperature cord wouldn't fit. My question is how do you know the state of charge of the service battery? I tested and my service battery was full at 12.95 volts but the electrics display was showing 75% state of charge most likely my starter battery level?

TheDocAUS · Apr 10, 2024

Knysna said:
Just finished my installation and tested with my solar blanket and functioning correctly I did need to modify the Black Sheep bracket and move my D250SE closer to the Smartpass because it rubbed on my seat supports and the battery temperature cord wouldn't fit. My question is how do you know the state of charge of the service battery? I tested and my service battery was full at 12.95 volts but the electrics display was showing 75% state of charge most likely my starter battery level?

The easiest way of monitoring the SOC of the main battery is to use a cheap battery monitor like the BLE. Some battery monitors reviewed here, including the BLE.

Karearea · Apr 10, 2024

TheDocAUS said:
The easiest way of monitoring the SOC of the main battery is to use a cheap battery monitor like the BLE. Some battery monitors reviewed here, including the BLE.

Awesome review Doc

TheDocAUS · Apr 10, 2024

Karearea said:
Awesome review Doc

BLE is resold under many names, so just look for the basic design at the right price, and price can vary a lot, so look around.

IG_in_AZ · Apr 11, 2024

globalgregors said:
So yes, those panels are out of spec for the D250SE.

Given you’ve already purchased what you have, if I were you I’d install the Renogy MPPT controller and run it direct to whichever battery you are running the inverter from (presuming the inverter is your largest consumer?).

I’d leave the D250SE as is, this will offer some redundancy or indeed an option to add additional solar if you find you’re consuming faster than you’re producing (which may be down to your local sun as much as energy use).

Our use case may be a bit different as we prep for remote use and diverse climates: I like to have a Plan B.

2000W is quite a bit of inverter… I wonder are you using an induction cooktop?

Wasn't sure what my power needs would be and really being ill-informed about the whole solar / invertor setup situation, I suppose I went a bit larger than I realistically need. Although, having a coffee maker or water boiler / kettle might be a nice option. I suppose in case of a natural disaster or extended power outage, I could theoretically power my garage freezer periodically to keep it's contents from thawing.

Thank you for your advice. I really appreciate it. So, running both CTEK and Renogy MPPT would be admittedly redundant but not completely impossible. As the old adage goes, two is one and one is none.

globalgregors · Apr 11, 2024

IG_in_AZ said:
Wasn't sure what my power needs would be and really being ill-informed about the whole solar / invertor setup situation, I suppose I went a bit larger than I realistically need. Although, having a coffee maker or water boiler / kettle might be a nice option. I suppose in case of a natural disaster or extended power outage, I could theoretically power my garage freezer periodically to keep it's contents from thawing.

Thank you for your advice. I really appreciate it. So, running both CTEK and Renogy MPPT would be admittedly redundant but not completely impossible. As the old adage goes, two is one and one is none.

Yes, great - happy to assist of course. A couple of items to bear in mind:

A consumer that operates below the inverter wattage may still not be usable with the combination of inverter and battery type and capacity we have. Coffee maker and kettle likely fine as they don’t operate for long durations. Induction cookers (and best check your freezer) might draw at a greater rate than the battery can sustain and will not have an automatic battery protection shut-off.
Inverters on standby have a draw, and the greater the inverter wattage the greater this will be. Best isolate and/or check that an inverter is properly powered down when not in use.

Apologies if you’re across this already, but it took me a while to get clear on such matters!

nuclearmonkey · Apr 11, 2024

globalgregors said:
Yes, great - happy to assist of course. A couple of items to bear in mind:

A consumer that operates below the inverter wattage may still not be usable with the combination of inverter and battery type and capacity we have. Coffee maker and kettle likely fine as they don’t operate for long durations. Induction cookers (and best check your freezer) might draw at a greater rate than the battery can sustain and will not have an automatic battery protection shut-off.

Inverters on standby have a draw, and the greater the inverter wattage the greater this will be. Best isolate and/or check that an inverter is properly powered down when not in use.

Apologies if you’re across this already, but it took me a while to get clear on such matters!

It’s my understanding that even with the power switch on, the inverter is only on standby when the engine is running… do we have confirmation on this?

globalgregors · Apr 11, 2024

nuclearmonkey said:
It’s my understanding that even with the power switch on, the inverter is only on standby when the engine is running… do we have confirmation on this?

I don’t know in relation to the OEM inverter @nuclearmonkey - ours is an Australian delivery (not offered).
The exchange above was in regard to an owner-installed Renogy unit.

21DFND · Apr 11, 2024

I decided to add a 100amp Slimline Lithium battery in the rear cargo area to run my drawer fridge as I was only getting a day and half of battery life from my second Ineos Battery. I already had my UHF mounted in from of the Cteck Smart pass, so I decided to mount the DS250SE next to the second battery, I made up a mounting plate. I connected it up as per the drawings using 60 amp fuses before the DS250SE and next to the Slimline Battery. Also connected the small red wire to the ignition power and the small black wire to constant power. All run well over the Easter long weekend, tested the solar input as well.

das mo · Jun 1, 2024

Hi.

Sorry bothering - I know there was a posting somewhere on a step by step installation guide for the 250, but I can´t find it.

Almost a year after stuck in the woods of Sweden with 2 empty batteries, I was able to grab an engineer at the Abenteuer Allrad Offroad Fair this week, discussing the voltage charts and he said my 120 is broken.

Long way coming. Hope to have it replaced soon and then finally ok to install the 250.

Thanks

Timo

ADVAW8S · Jun 1, 2024

das mo said:
Hi.

Sorry bothering - I know there was a posting somewhere on a step by step installation guide for the 250, but I can´t find it.

Almost a year after stuck in the woods of Sweden with 2 empty batteries, I was able to grab an engineer at the Abenteuer Allrad Offroad Fair this week, discussing the voltage charts and he said my 120 is broken.

Long way coming. Hope to have it replaced soon and then finally ok to install the 250.

Thanks

Timo

There is a video on YouTube from @Ragman of how to install the 250. His site is called dickin around outdoors.

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