CTEK D250 Dual, Installation Problems (1 Viewer)

[Revolvor]

This is a follow-on to my post below, and as before I will be grateful for any help/advice:

http://www.motorhomefun.co.uk/forum/threads/help-with-btb-charger-wiring-please.117498/

I finally took the plunge and purchased a CTEK D250 Dual, to allow me to fully charge the leisure batteries when driving, and also to accept the solar panels I plan to fit later this year.

Link to CTEK D250 Dual: http://www.ctek.com/Archive/ProductManualPdf/D250S DUAL_EN.pdf

However, I seem to have taken one step forward and two steps back!

I have a 2008 Fiat Ducato based Autotrail Motorhome, fitted with a Sargent EC225 Power supply and EM50 interface unit.

The problem I have is that in order for the CTEK unit to work correctly, I believe that I need to disable the existing connection that charges the leisure battery when the engine is running, and allow it to be charged only from the CTEK D250.

I had hoped that all I needed to do was to remove Fuse #8 in the EM50, and last year when I did that, it seemed to be the case. However, prior to the D250 install, I checked that again, but now find that I am still getting a voltage rise at the leisure batteries when the engine is started.

Link to EM50 Data Sheet: Link Removed

I have had this response from Sargent today "

"As the split charging is a built in function of the main PCB in the EC225, the only way you will be able to disable it without affecting other systems is to use a high current relay to disconnect the vehicle battery supply when the engine is started."

I had come to a similar conclusion myself, but now I need a means to energise the Relay! I will connect the relay in the cable from the EC225 to the leisure batteries, so that it goes "Open Circuit" when the alternator is charging.

Will I have to utilise a "voltage sensing" split charge type relay, or can I use one connected to the Alternator D+ terminal? If I go the D+ route, please can anyone tell me where I can find a connection in the Ducato wiring, other than directly off the difficult-to-access alternator?

Thanks,
John

 

[Revolvor]

Since my post above, I have had another thought ........... The 2x 12v/cigarette sockets on the dash only become live once the engine is running. They are NOT live when just the ignition is on.

Is there any practical reason why I cannot utilise that supply as a 12v source to operate the relay to disconnect the Sargent EC225 from the leisure batteries when the engine is running?

John

 

[Revolvor]

Installation update:

I solved the problem of the Sargent unit also charging the Leisure Batteries whilst driving by following Sargent's advice, and fitted a relay in the feed from the charger, which goes open circuit when the engine is running. I took the 12v relay coil feed from the EM50, linking into the 12v signal to the fridge. I followed all recommendations from CTEK relating to cable sizes/lengths, and initially it all seemed to work exactly as it should. The correct lights came on to show the leisure batteries were charging, about 30 seconds after starting the engine, with 14.3 volts at the leisure batteries. (I wasn't able to measure current)

As it was a new installation, I kept an eye on it and checked that it was working, every time I used the van. However, last week I noticed that only the standby lamp was showing, even with the engine running. Voltages of leisure and vehicle batteries measured at the CTEK are correct, so no fuses have blown. I have deliberately let the leisure battery discharge, by leaving lights on all day, but still no joy.

Does anyone have any suggestions as to what I could try, before I start the long process of getting it returned? ... purchased through Amazon, who just say return it to CTEK.

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