CTEK connection question

[4Burner]

Hi guys, I had a dual battery system fitted and the Auto elec has used a CTEK D250S Dual DC to DC charger to manage the second battery.

It's fitted to a 2013 Thai RX. Now according to the CTEK diagram a relay is used to shut of the primary battery. See below.
CTEK tell me it must have the relay regardless of a solar panel otherwise it will drain the primary battery. Auto elec says the CTEK manages both batteries so no need.

Anyone got the same set up that can point me in the right direction.

 

[TigerST]

I love Ctek in some things but that bloody relay is a silly idea.

Ok you have a smart alt so the D250S pluged in the battery will thing the car is off when the alt powers down. So you need the relay so it shut off with the key. As you'll need yo plug it in to the solar input. Without the relay your batteries will aslways been connected.

Redarc got it right
http://www.redarc.com.au/products/product/20a-in-vehicle-battery-charger-ignition-control/

 

[Old.Tony]

Use the relay. I have one, guarantees when my engine isn't running, the cranker is NOT having any auxiliary system drawing from it.

The auto electrician is SORT OF right, but the D250S will still draw a small amount of current to look at the input.

If you have a later model car and need to use the relay on the solar input (we can talk about that later), then you need a SECOND relay to shut the input down when the engine is off. The battery input should stop drawing when the voltage is low (your auto lecky is therefore right, with the caveat in the previous paragraph), but the solar input will suck like mad from anything it can grab, because that's the way it works with solar.

It was designed so that the car input would need a certain voltage to trigger the D250S into charging, but if the solar panel presented half a volt it'd try and use it. It got buggered up by the "smart alternators".

 

[Patrol_dave]

I thought the ctek would only draw once the voltage from main battery exceeded 13.1 and would drop when voltage returned to below 12.8. That's certainly what my manual states. I have no relay, I also do not have a solar panel. To date all has worked great. I too have an RX.

 

[Old.Tony]

^ while that's true, and while C-Tek is (I believe) one of the best products you can buy, there's nothing like being safe. Draining the cranker on the CSR is absolutely NOT what you want to do and for the cost of a relay ... call it insurance.

 

[4Burner]

Hi, thanks for the replies, I think what you say is right, the relay is cheap insurance.
What I might do is monitor the system with a multimeter over Easter as we are away for a week and see how it goes. I'll be in a caravan park anyway so a jump start should be too far away if need be.... And it will get some laughs.

Cheers.

 

[PeterM]

Guys,

My vehicle id a 2011 Spanish STX - I installed a cteck D250S in the rear tray similar to the photo above ( I actually have a set of drawers so is fully enclosed). As a test I bypassed the relay and found that whilst it was charging at 14V it did drain the front battery very quickly (engine was not running) - Works well so far but would not recommend leaving it wired that way

I previously had a Redarc SBI installed but did not keep up the charge. As I already had heavy wiring to the rear Redarc recommended that I move the solenoid to the rear and dumb it down which I have done. I fitted a toggle switch and beeper to pull in the solenoid and connect the two batteries enabling me to boost the front battery if it is low - Sort of like a set of jumper leads

I have 2 questions:-

1. The diagram above shows the input wire going to the solar panel connection on the cteck but the photo shows it going to the alternator connector. Does it matter ? Maybe they are common inside the charger and just 2 alternative inputs.

2. I need to get a feed to trip the relay from a source that is live when the ignition is on and only then. Where is the easiest place to do this ? Up under the dash or under the bonnet ?

 

[glennm]

Use the relay. I have one, guarantees when my engine isn't running, the cranker is NOT having any auxiliary system drawing from it.

The auto electrician is SORT OF right, but the D250S will still draw a small amount of current to look at the input.

If you have a later model car and need to use the relay on the solar input (we can talk about that later), then you need a SECOND relay to shut the input down when the engine is off. The battery input should stop drawing when the voltage is low (your auto lecky is therefore right, with the caveat in the previous paragraph), but the solar input will suck like mad from anything it can grab, because that's the way it works with solar.

It was designed so that the car input would need a certain voltage to trigger the D250S into charging, but if the solar panel presented half a volt it'd try and use it. It got buggered up by the "smart alternators".

Thanks Tony i think that explains the small drop in my cranker compared to the aux. Thought i might have had a sus battery.

 

[TigerST]

Guys,

I have 2 questions:-

1. The diagram above shows the input wire going to the solar panel connection on the cteck but the photo shows it going to the alternator connector. Does it matter ? Maybe they are common inside the charger and just 2 alternative inputs.

2. I need to get a feed to trip the relay from a source that is live when the ignition is on and only then. Where is the easiest place to do this ? Up under the dash or under the bonnet ?

1. Only if you have a Smart Alt as once charged they drop as low as 12volts

2. Only place I can thing of is in side the cab.

 

[Old.Tony]

I have 2 questions:-

1. The diagram above shows the input wire going to the solar panel connection on the cteck but the photo shows it going to the alternator connector. Does it matter ? Maybe they are common inside the charger and just 2 alternative inputs.

2. I need to get a feed to trip the relay from a source that is live when the ignition is on and only then. Where is the easiest place to do this ? Up under the dash or under the bonnet ?

1) The solar input will take any power level and boost the hell out of it to produce the right power to charge the battery. Connected to a cranker with a stopped engine, it should draw like mad from it until the cranker can't supply any more power and that input will need to be prevented from doing so by a relay. The relay that's in the diagram is to switch between solar panel and "smart alternator", providing either source to the solar input (which will do its boosting etc). The alternator input expects 14.1V or so and should turn off if the voltage falls below 13.2V. If it does, that's why you have another relay that is only active when the ignition is on.

2) Behind the battery is a black box that's called the IPDM/ER (Intelligent Power Distribution Module/Engine Room). There are a number of sources in there that would be useful.