Jump to content

B2B Charger - Possible conflicts???


sshortcircuit

Recommended Posts

I have just fitted a Ctek D250S B2B charger to my MH. I have ignored the existing wiring through the split charge relay as the Ctek can provide up to 20Amps from the alternator to charge the leisure battery and the wiring just was not up to carrying this current over the distance required. The D250S has been located near the leisure batteries and wired using 7m of 10mm. In addition the earth from the leisure battery was taken to the chassis as should have been done by the manufacturer. No point in using 10mm to supply unit and then rely on existing wiring which was too small. I have also connected a solar panel into this unit rather than a separate regulator. Operation shows good at the moment.

 

Not sure what effect the existing supply from the split charge will have with the output from the Ctek at the same time. Any advise please.

Link to comment
Share on other sites

I note that the RoadPro website carries some information on the D250S DUAL B2B device and I presume the charger is supplied with full fitting instructions.

 

If you are asking about whether it's advisable to disconnect the existing link between the split-charge relay and the leisure battery, then I don't know.

 

If I were in your position I'd a) study the charger's installation instructions carefully, b) if these did not include mention of whether existing wiring should be altered, I'd c) contact people who have expert experience of the charger (CTEK obviously and possibly RoadPro) and d) if I were still uncomfortable with the idea of retaining the link between relay and battery (and I probably would be), I'd disconnect it.

 

As it must be commonplace to install a B2B charger on a motorhome that has an existing split-charge relay system, I would have thought it would be essential to cover in the installation instructions whether or not that existing system can safely be left unmodified.

Link to comment
Share on other sites

Thanks Derek. Unfortunately the instructions that come with the unit are not all that great. Have looked on the RoadPro site and manual and instructions are as supplied with the unit. The notes on installing B2B is a broken link. Had thought of fitting relay to isolate leisure battery when charging but that is becoming messy.

 

As you say not an uncommon installation and I will look at other product eg Sterling

Link to comment
Share on other sites

I notice that there are sample wiring diagrams for a STERLING B2B system here

 

http://www.marcleleisure.co.uk/Sterling/SterlingBatToBattCharg02.htm

 

However, there doesn't seem to be anything about the advisablity of adding a B2B device but leaving in place the original split-charge-relay feed to the leisure-battery.

 

There's also this earlier thread (that you may well have seen)

 

http://www.outandaboutlive.co.uk/forums/forums/thread-view.asp?tid=22191

 

that suggests that Dave Newell may be able to give you Yes-or-No advice for regarding the split-charge relay issue based on hands-on experience of the CTEK device.

Link to comment
Share on other sites

sshortcircuit is a very appropriate name for what you have just installed.

 

Think about it, when you start your engine and the split charge relay closes you have in effect short circuited the input to the output of the B2B 5 stage charger. So, no, not desirable to have the split charge relay left in circuit unless it was supplying the feed to the B2B as a charge source.

 

 

Link to comment
Share on other sites

Thanks for all the contributions and I will need to take time and read through them. I asked the question as rather than shortcircuiting the B2B it appeared to me that I am now paralleling two battery chargers to the leisure battery, one through the B2B and the other through the split charge relay.

 

The split charge supply would increase its charge rate as the B2B had induced the alternator to increase its output although this would be reduced by the size of the existing wiring. The B2B would also charge the batteries at a higher rate although my concern is that its 5 stages will be confused because of the split charge relay input.

 

In order to seperate the chargers it would appear that I would need to fit a switch or relay at the leisure battery to isolate the split charge input and use the B2B only when engine running. Not to difficult to achieve but an added complication and remembering to change over when stopped.

 

Have contacted Ctek as this cannot be a unique situation but would be grateful for any suggestions. ;-)

Link to comment
Share on other sites

Hold on, stand back a minute and have a look again and what you are trying to achieve. I take it you are trying to use the B2B to charge from the alternator with the engine running. The split charge relay only operates when engine running so fitting an isolator would be the same as just leaving permanently disconnected. Am I missing what you are trying to achieve?

 

The 2nd function is when parked up is to take the solar power and use the B2B to manage the Solar power and also charge the leisure battery along with the nice feature the one you are using has, of trickling some of the power back into the engine battery.

 

Link to comment
Share on other sites

What I was trying to achieve was to isolate the split charge relay charging current at the leisure battery when the engine is running in order that the B2B only is charging as designed.

 

I understood that with the engine running the split charge relay provides a charge to the leisure battery which would conflict with the B2B. A separate switch/relay at the leisure battery isolating the split charge relay feed when the engine running was what I was suggesting.

 

The 2nd function was why I went for the Ctek unit as I fitted a solar panel at the same time which will as you say, provided we get sufficient sunshine, charge the leisure and starter batteries.

 

Very much appreciate your input and hope I am clear enough

 

 

Edit Having digested your earlier posting and looked at the Kontiki circuit diagram I only need to disconnect the the positive output from the split charge relay and that will leave the B2B on its own

 

Link to comment
Share on other sites

"Edit Having digested your earlier posting and looked at the Kontiki circuit diagram I only need to disconnect the the positive output from the split charge relay and that will leave the B2B on its own "

 

Yes, I agree with this.

 

 

Link to comment
Share on other sites

Thanks very much for your guidance Jon.

 

I have very much appreciated what I have learned from this posting. What has come through is that the instructions provided by the manufacturers fall very much short. I am lucky I have the background knowledge to appreciate that the unit would not operate correctly and start to ask the questions, not bad for one of the auld codgers.

 

Thanks again

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...