Renogy B to B

[Kelvin8tor]

I fitted a Renogy battery to battery charger with solar MPPT all seems to work well apart from the fridge which no longer works in 12 volts
My Swift bolero has the Sargent ec 600 control system and I followed the advice from them to fit a relay to the leisure battery connection to the control panel that disconnects it when the engine is running using the alternator running signal D+ E6 terminal on the ec 600 control board the leisure battery connection is E8 on the ec 600 the relay works as it should but fridge does not switch to 12 volts and oddly the reversing camera stopped working
If I disconnect the D+ from the relay everything works but I don’t want to leave the Renogy connection to stater battery complete until I can solve this problem
The file that I was sent from Sargent only shows one wire connection from the ec 600 but it actually had 2 the relay that I fitted disconnected both cables ( I thought that it had 2 cables as they were quite small compared to the cable i fitted myself ) perhaps only one should of been disconnected if so which one? Who knows
Thanks in advance
Kelvin

 

[autorouter]

The main leisure battery connection to the EC600 is the 4-way E8 connector. The fuse on that wire is 40A near the battery. The positive and negative connections are both doubled up because the E8 spade terminals are not big enough to take the full amps current. The amps is shared between the two positive terminals so the terminals aren't overloaded and don't get too hot. The same for the two negative terminals.

The relay used to disconnect that wire needs to be quite a hefty one, since the wire is fused at 40A. You need to connect the pair of positive wires from the leisure battery to a single power terminal on the relay. Connect the pair of positive wires from the E8 connector to the other relay power terminal. The relay power connections will be capable of handling the amps, so it's OK to connect the pair of positive wires to a single terminal.

 

[autorouter]

What kind of relay are you using to disconnect the EC600 from the leisure battery using the D+ (engine running) signal? A standard 4-terminal relay won't do it. There are only two power terminals on a standard relay, and they are usually 'Normally Open' (NO). That means they are not connected when the engine is stopped and the D+ signal is zero. You want one that is 'Normally Closed' (NC), so that it is connected when the D+ is zero, and disconnects when the D+ goes to 12V.

If you can find an NC relay you are lucky, they can be difficult to find. However it's easier to find a 5-terminal relay, which can be used instead. A 5-terminal relay has three power terminals. There is one common (COM) terminal, that switches from the NC terminal to the NO terminal when the coil is energised by the D+. You can use the COM and NC terminals, and just ignore the NO terminal.

If the relay has a built-in diode across the coil terminals, it's important to connect the D+ and Negative the correct way round on the coil terminals.

 

[Kelvin8tor]

The main leisure battery connection to the EC600 is the 4-way E8 connector. The fuse on that wire is 40A near the battery. The positive and negative connections are both doubled up because the E8 spade terminals are not big enough to take the full amps current. The amps is shared between the two positive terminals so the terminals aren't overloaded and don't get too hot. The same for the two negative terminals.

The relay used to disconnect that wire needs to be quite a hefty one, since the wire is fused at 40A. You need to connect the pair of positive wires from the leisure battery to a single power terminal on the relay. Connect the pair of positive wires from the E8 connector to the other relay power terminal. The relay power connections will be capable of handling the amps, so it's OK to connect the pair of positive wires to a single terminal.

 

[Kelvin8tor]

I have followed the above diagram and used a 40 amp 5 pin relay with diode this is installed next to the wc 600 control board
Thanks for the replies

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[autorouter]

The terminal on the E6 connector is labelled 'Low D+'. This terminology is not totally standard across the industry, but to me it suggests that is what's called an 'active low' connection rather than the more usual 'active high' type.

Active high means the D+ is +12V with engine running, and zeroV when stopped. This is the usual D+ signal.
Active low means the D+ is zeroV with engine running, and +12V when stopped. This is used on some vehicles, but is not common.

It should be easy to test this with a multimeter, to see which way round it is. Some B2Bs have two control inputs - active high and active low. Some have one input, but can flip between the two modes with a slider switch or a firmware setting. If no provision has been made, it is possible to change from one mode to the other using a 5-terminal relay - only a small relay is required because it takes a very small current.

 

[Kelvin8tor]

Thanks for your reply
The relay does exactly as it should in that when the engine is running it disconnects the power to the leisure battery I have tested with my trusty Fluke multimeter so as far as I can tell it is all connected as the diagram from Sergeant I have disconnected the low D+ at the moment and disconnected the supply to to Renogy from the vehicle battery all I’ve managed to achieve at the moment is solar through the Renogy
The Renogy does not require the D+ signal as I do not have a smart alternator
I’m beginning to think my problem may be that the relay that I have fitted should be fitted much closer to the leisure batteries. This perhaps is something I’ll try when I get back from my latest trip.

 

[autorouter]

Is the starter battery power definitely getting through to the E7 connector?

 

[Kelvin8tor]

Yes power at E7 every works as it did with the extra relay that I fitted disabled
I have wired the Renogy battery to battery completely independent of any or the Sargent wiring ie 16mm square cables from engine battery to the renogy and then onto the leisure battery’s from the Renogy
It’s a 30amp Renogy B2B
My thoughts are that the cables from E8 must supply the fridge on its way to the leisure battery’s and that I have disabled this with the relay in the wrong place ie should be next to the leisure battery rather than the EX 600 controller unit
Thanks again for your response

 

[autorouter]

Yes power at E7 every works as it did with the extra relay that I fitted disabled

Can you clarify that? The starter battery power should be reaching connector E7 all the time, no ifs or buts. It should be coming from the B-Pillar connection, and the relay should have no effect on it at all.

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[Kelvin8tor]

Yes l have confirmed that power is at E7
The E8 connection goes to the leisure battery as per the diagram from sergeant like I said everything works as it was originally intended if I disable the relay that I fitted to the E8 connection to the leisure battery
So to clarify if the relay I fitted is disabled the Sargent system works as it should
With the relay connected and engine running the fridge does not work or the reversing system camera but the Renogy works as it should charging the leisure battery’s from the alternator solar works and charges both batteries leisure and engine. I have disabled the relay as it is more important at the moment to have the fridge work on 12 volt and the reverse camera as we are touring western France and sun is plentiful so the 300 watts of solar through the Renogy keeps the leisure battery’s full