Wiring your Lynx Smart BMS

Posted by Peter Kennedy on 2/7/2023 to Batteries (Lithium Ion)

The Lynx Smart BMS is a dedicated Battery Management System for Victron Lithium Smart Batteries. There are multiple BMS's available for Victron Smart Lithium Batteries, and the Lynx Smart is the most feature rich and complete option. Its main features are:

Built-in 500A contactor used as a fallback safety mechanism and also suitable as a remote controllable main system switch.
Battery monitor, indicating state of charge percentage and more data.
Pre-alarm signal: provide a warning before the system shuts down due to -for example- a low cell.
Bluetooth for use with the VictronConnect App, for setup and monitoring.
Local and remote monitoring using the Cerbo GX.
The Lynx Smart BMS is part of the modular Lynx Distribution system.

The instruction manual is the most complete guide to wiring up the Lynx BMS. I made the following video to explain everything in an easy to understand way but if you see any discrepancies the manual takes precedence. Further down you will see a summary of the text from the video along with some additional notes, a copy of the wiring diagram and some additional information.

Here are some notes about the cables discussed in the video:

Battery Data Cables. You will probably need some extension cables to enable them to reach the BMS. These come in packs of two with lengths of 1, 2, 3 and 5 meters. Here is the 2 meter one: Victron Energy ASS030560200 M8 circular connector Male/Female 3 pole cable 2m (bag of 2)
VE Can Network. This uses RJ45 cables. The network terminators are included with any device that uses them, your Lynx BMS should have come with a pair, so did your Cerbo GX. If you have lost them we sell them here.
RJ10 cables come with the Lynx Distributor. If you have multiple Lynx Distributors the can daisy chain them. If you want to space the Lynx Distributors further apart and need longer RJ10 cables you should be able to find some online, we don't have any for sale, sorry.
The big red battery switch shown in the video is the Blue Sea 6006. The small toggle switch I used in my demo is the Blue Sea 4150
The fuse block I used in the video is the Blue Sea 5045. I used Blue Sea 5235 ATO/ATC 1 amp fuses. Note that these fuses are not suitable for use in a 48 volt system. In fact I was unable to source any suitable fuses for a 48 volt system. In all the 48 volt systems we have been involved with there was a 12 or 24 volt battery available to power all these small connections. As long as both battery systems share the same negative it is OK to power or control these small items from a different voltage.
The negative terminal block I used was the Blue Sea 2314 mini busbar.
The alarm I used was the Blue Sea 1070
The BatteryProtect was the Victron Energy BPR110022000 Smart BatteryProtect with Bluetooth 12/24V-100A

There is an alternate way to wire the control wire to the Smart BatteryProtect. It doesn't require any power or a fuse block and it is discussed in the instruction manual. I chose to do mine the way I did because there might be multiple things I want to control and my way works for every situation whereas the alternative method only works in certain situations. In any case I am going to need fuses for the Cerbo GX and the alarm so one or two more is not a hardship, the four gang fuse block is the smallest I could find.

Here is a detailed photo of the terminal area:

And finally, here is the wiring diagram I used in the Video, you can right click on the image and open it in a new tab to see a larger version:

1 Comments

Robin Wessel

Date 5/15/2023

Thanks for sharing. Question - I noticed that Victron has a schematic that shows the ATC connections wired through the relay connections for the Wakespeed regulator. I believe Wakespeed's simplified diagram shows the connection only to the relay and not the ATC connection. Do you know why it is wired via the relay from the ATC or per Wakespeed's diagram shows, only to the relay? If the lynx BMS controls the charging devices including the Wakespeed regulator, is the extra ATC wiring required?

Peter Kennedy

Date 5/16/2023

The Wakespeed alternator regulator has an integration with the Cerbo GX using VE Can. When used with the Lynx BMS or the new VE Bus BMS the DVCC (Distributed Voltage and Charge Control) function of the Cerbo cuts in and changes the Cerbo from being a passive monitor into being an active controller. The Wakespeed will show up as a device on the Cerbo and the Cerbo will be able to reduce or stop alternator charging any time it wants. There is a special crossover cable required to connect the Wakespeed into the VE Can network but no other wiring is required. This will be the subject of another video as soon as I can find the time. DVCC is explained further in the Cerbo manual

Jason Evans

Date 1/10/2024

Very informative, thank you! What if you have a 24V system, and downstream from the SBP there are 24V loads, plus a 24/12 converter for 12V loads. I have read on the Victron forum where an SBP can be damaged by the capacitive input of the converter. How would you recommend handling this case?

Jamal

Date 2/21/2024

Thank you for sharing. This is great! going to attempt to wire a 48v system and I get lost in the diagrams. Do you have a recommended wire size for these connections?

Date 2/22/2024

You can refer to the Ampacity Tables to see the minimum wire size allowed for any particular current. In DC Systems voltage drop becomes an issue and the Voltage Drop Tables will normally recommend you a larger wire size than the minimum. There are two values in the tables: a 3% voltage drop for essential loads (in a boat that would be bilge pump, nav lights, navigation equipment etc) and a 10% voltage drop for non essential loads (windlass , winch, refrigerator etc)

Wiring your Lynx Smart BMS

1 Comments

Robin Wessel

Peter Kennedy

Jason Evans

Jamal

Peter Kennedy

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