Renogy 12V Lithium ion battery - Sargent EC160

[1mperialSoldier]

Removing the charger fuse will isolate the Sargent internal charger.
I've got the EC160 unit but it's the same deal, if you've got a Durite or similar ignition controlled split charge relay under the drivers seat with the existing leisure battery then that will need removing and the ignition trigger wire connecting to your B2B charger along with the alternator incoming feed (VW 75A fused fattish black wire) and your outgoing leisure battery fat wire feed.
Put fuses everywhere and a big ie 300A battery isolator switch at the leisure battery to prevent back leakage through the charger, inverter or any other kit that will drain the leisure battery when not in use or when you want to connect additional stuff to the battery safely.
I added a Renogy shunt with remote display to show what's going in/out and remaining duration on my setup and it's a great graphical indication of the leisure battery state of play rather than slightly misleading phone apps and Bluetooth combo.

Thanks for the tip on the durlite relay, the issue I have now is the EHU won't power the 230v sockets, Unsure why. However whoever installed the EC155 made it so to change anything on the unit I had to remove all the cupboards at the back so that was a fun 5 hours

 

[Stay Frosty]

Make sure the MCBs in the Sargent are turned on, realistically there's probably just the one 16A one being used for your campers mains skts.
On mine I used one of the other two spare MCBs in the Sargent to power a 13A skt by the drivers seat for a 30A smart charger for the leisure battery when on hook up.

 

[1mperialSoldier]

Make sure the MCBs in the Sargent are turned on, realistically there's probably just the one 16A one being used for your campers mains skts.
On mine I used one of the other two spare MCBs in the Sargent to power a 13A skt by the drivers seat for a 30A smart charger for the leisure battery when on hook up.

That's I think they were all on, I will check some point this week. I'm not too fussed as the lithium battery runs everything and charges which is a bonus. But definitely want the EHU to work before out next long camp

 

[Ian1966]

That's I think they were all on, I will check some point this week. I'm not too fussed as the lithium battery runs everything and charges which is a bonus. But definitely want the EHU to work before out next long camp

Mine is the same I’ve got lithium to run everything. I can also use EHU but obviously won’t charge lithium but will allow us 240v sockets should we need them.

 

[M18BTE]

@Stay Frosty how are you getting on with the set up? been reading over the thread multiple times getting my head around it and I think I want the same outcome as you. I've got the ec160 and a lead acid battery but I want to upgrade it to a Lifepo4 as i can be offgrid. I already have a victron MPPT for my solar so that should work with the Lifepo4. Am I right in saying I need a Victron dc-dc charger for when the starter batteries running? I think if I unplug the right cables in the back of the ec160 then when on ehu it will just power sockets and in one socket i need a victron ip65 connected to my leisure battery to power all the 12v system?

 

[Stay Frosty]

Hopefully I'll remember this correctly but yes to a B2B charger to charge the leisure battery from the vans alternator.
Ditch the Sargent unit 12 volt charger which is a case of pulling the fuse and disconnecting the existing feed from the EC160 to the leisure battery, in my case with Redlines conversion there were two wires which went to an old school leisure battery split charger so you could charge the starter or leisure battery when on hookup.
I used a spare way on the 230v side of the EC160 to add a 16A domestic MCB and feed a conventional surface mount single 13A switched skt in 2.5mm2 blue arctic flex on the side of the fridge housing and that powers a stand alone 30A Victron IP22 smart charger.
The basic install went easily enough but getting the right fuse type for the 12v side of things took a while to get right as I started off using some old kit I had from my car audio days back in the day and AGU glass tube type fuses are no good with 80 and 100A loads at 13.8 volts they either blow or worse the lead at the end of the fusible link melts and gives a continuity reading on multimeter but won't carry any real current.
Go lithium and if you're feeling lucky add solar, we've had literally hours of fun getting ours to play nicely but worth it when you know you can survive without an electrical hookup.

 

[M18BTE]

Thanks for the reply even though its been a while really helpful. What you have described is pretty much what I had in my head I just wanted to makesure it will work before i bit the bullet and brought things. I've just ready about the IP22 smart charger so will probably go for that too. I've not thought about the fuse side of things yet I was hoping that would be the easy part!

Already got solar It didnt work when I purchased it and I've got it working now, that was fun figuring it out and learning so lithium is my next project