Renogy DC to DC charger - Battery Switch

[Jon on Whisper]

I have a Renogy 50amp DC to DC charger with an AGM starter battery and a Lithium 300aH house battery. I purchased a Blue Sea 5511e battery selector switch... where should this be placed in the circuit? Or, should I have two separate on/off switches, one for each battery? Thanks in advance for the help! Jon

[wholybee]

What do you want to accomplish? Do you have a wiring diagram of your system as it is wired now?

[Jon on Whisper]

I want to be able to switch off the batteries in case of emergency, etc. I haven't seen a diagram showing placement of the battery switch on any Renogy DC to DC posts. I'm thinking that a switch just after each battery is the way to go... but would like a second opinion.

[smac999]

Connnect direct to each battery (or after shunts) and Fuse at both ends. I assume that unit Only comes on when the start battery is charging. So why would you ever turn it off.

[wholybee]

Originally Posted by Jon on Whisper

I want to be able to switch off the batteries in case of emergency, etc. I haven't seen a diagram showing placement of the battery switch on any Renogy DC to DC posts. I'm thinking that a switch just after each battery is the way to go... but would like a second opinion.

The switch you have is just 2 switches in one case. The connection should be for each battery: Battery positive->fuse->switch->your loads

If your LFP battery has a separate BMS it could vary a bit there, we would need to see a drawing. But if you have a drop in with built-in BMS, connect it the same as the AGM.

[ben373]

Originally Posted by wholybee

The switch you have is just 2 switches in one case. The connection should be for each battery: Battery positive->fuse->switch->your loads



If your LFP battery has a separate BMS it could vary a bit there, we would need to see a drawing. But if you have a drop in with built-in BMS, connect it the same as the AGM.

2 separate switches is better

[Jon on Whisper]

Thanks all. I greatly appreciate the second opinion.