Fitting a a batter to battery

I am considering  fitting a renogy 20 amp battery to battery  charger  to my nuevo with Sargent 328 system . How do find and  disconect  the  VSR  from the sargent system  so the L B  is only charged  from the  BtB   and not forming a loop . ?

EC328, does this mean you have the EM50. If so then could it really be as simple as removing 2 wires from a plug in connection. It maybe, no guarantees from me, it needs a bit of study of the installation.

Or merely Remove F8, another possibility, depending on model.

No interference with the engine run signal.

If so you are the envy of many a EC500/EC700 user.

What a shame that all steps from Sargent seem to be backward ones.

If you disconnect the D+ input to the EM50 you will lose automatic step retraction and the 12v supply to the fridge when the engine is running as well as losing  the engine run signal to the EC328 that does other things in addition to operating the split charge relay.

I have not tested this, but information supplied by Sargent and the installation in my van suggests that the third wire connected to the switched 12v out on the EM50, in addition to the supplies to the fridge and rear camera, is taken to the EC328 as the engine run indicator.

Just to test things, you could remove the 4 way connector in the EM50 that will allow you to confirm that the split charge system is deactivated and find out what other side effects could be - obviously the fridge won't work during that test.

Peter Brown wrote:
Just to test things, you could remove the 4 way connector in the EM50 that will allow you to confirm that the split charge system is deactivated and find out what other side effects could be - obviously the fridge won't work during that test.

Yes that's the first test I would do, pull out the plug with the Brown/Blue, Red/Yellow cables and see if anything else if effected, ignoring the fridge, if its OK you can put the R/Y's back, the Camera feed wont be effected. Or have they set a trap.

Thanks for advice , their are lots of  BtoB fitting videos  on utube  but none mention  existing  charging  system's,

Molly3 wrote:Thanks for advice , their are lots of  BtoB fitting videos  on utube  but none mention  existing  charging  system's,

I can't give full details of wiring, anyone capable of doing the job safely will be able to work out the details, fusing etc. and just ask if there are any queries.

As far as the actual B2B goes obviously having not done it I can't recommend there either. I have not mentioned it in other threads or in my diagrams yet but with Sargent systems personally I would use the Victron Orion-Tr Smart  12/12 30 Isolated.

Thanks for information  ,  definitely  not  as plug and play  as I was hoping  , especially  as so many  motorhomes  use sargent   system .