Victron State of Charge

[caymaanedge]

My available Ah and SOC don’t seem to reset very accurately when recharging.

Woke up this morning to this 56% SOC
Couple hours later with very little use and decent Solar coming in I am down to 50%. Battery voltage is higher.

Drawing about 2 amps @120v
Do I have something wrong in setting?

680ah LifePO4
1140 watts Solar

 

[sunshine_eggo]

Is this a new installation?

Is the ONLY thing attached to the main (-) terminal of your battery the shunt with EVERYTHING, loads and chargers, attached to the other side of the shunt?

Have you attached other devices to the main (-) terminal of your battery(ies)?

Picture of battery with shunt connected would help.

What is your bulk/boost/absorption voltage?

Provide all smartshunt settings please.

 

[caymaanedge]

Not a new installation and this has never seemed to work properly.
All the items connect to a Lynx bus setup. The Smart Shunt is the only thing from the Lynx ground to the inverter.

 

[sunshine_eggo]

Not a new installation and this has never seemed to work properly.
All the items connect to a Lynx bus setup. The Smart Shunt is the only thing from the Lynx ground to the inverter.

Should be:

Battery > shunt > Lynx > loads/chargers

If it's:

Battery > lynx > PV charger
Battery > lynx > shunt > inverter

You have bypassed your shunt on PV charging.

ALL current to and from battery MUST pass through shunt for shunt to be accurate.

Once you fix the installation:

Shunt settings:

• Charged voltage: 0.2V below PV absorption voltage. PV charging can provide unreliable current and may trigger false sync.
• Set battery SoC on reset to "Keep SoC" - your current setting will set 100% SoC even if the battery is empty. With "keep soc," it stores the last known SoC and uses that on next startup.

 

[caymaanedge]

Thanks
Pretty sure the batteries and solar charger all connect to Lynx directly. Shunt on Lynx ground lug to inverter.
I need a bus for the 4 batteries so the Lynx works well. How should I connect the solar input to the batteries? Do I need a second Lynx with the shunt in between them? Makes sense and thank you for the help.

Can I put the solar controller ground on the inverter side of the shunt? Leaving the power lead on the Lynx.

 

[justinm001]

The Smart Shunt is the only thing from the Lynx ground to the inverter.

There's your issue like Eggo said the shunt goes right after the baytery - it monitors power from/to the batteries from everything.

Your solar is charging the batteries but the shunt isn't seeing it so isn't adding to the SoC.

 

[caymaanedge]

Totally makes sense.
Can I just move the solar charger ground to the inverter side of shunt. I could make that happen pretty easily. Otherwise I’d have to wait until I get home in a month.
Currently boondocking at the Rincon Parkway in Ventura, CA.

 

[Rocketman]

If it fits get a Victron PowerIn for a bus bar for the batteries. It nice and organized.

Probably you could move the charger neg to the load side of the shunt- - but that bolt is really short - may not be enough threads for it.

A photo of the equipment may help in answers.

Good Luck

 

[justinm001]

Yes as long as it fits. You can always just get a longer bolt at a hardware store for that side.

 

[justinm001]

If it fits get a Victron PowerIn for a bus bar for the batteries. It nice and organized.

Probably you could move the charger neg to the load side of the shunt- - but that bolt is really short - may not be enough threads for it.

A photo of the equipment may help in answers.

Good Luck

Lynx distribution bus is worth getting over just the power in. It's the same thing but has fuse mounts and a board so if you use the lynx shunt it'll light up. Kinda dumb they didn't just make it light up on its own. Even if using for the battery side it's nice to have fuses for each battery just incase.

BTW I have the lynx shunt and distribution buss and although the lights light up idk if it tells cerbo if a fuse failed.

 

[Adam De Lay]

BTW I have the lynx shunt and distribution buss and although the lights light up idk if it tells cerbo if a fuse failed.

Unfortunately I don't think it does. It seems to only work if you have the Lynx BMS, not the shunt.

 

[Rocketman]

For your Smartshunt settings here are the items to think about changing:

Charged voltage: .15 to .2 below the Absorption voltage( My settings- Absorption 14.25 in the mppt - Charged voltage 14.1)

Your tail current and charge detection time are fine - I like a lower tail current 2% and a longer detection time 5min.

I find this reduces the false 100% when cloudy - probably doesn’t matter much.

I also changed the charge efficient factor from 99% to 98%. What this does is if I don’t reach 100% that day, the SOC% ends up about 1% lower that what I find really in the batteries. The net effect is after 10 days of not getting to 100%, the SOC could say 54% while the battery is really about 64%. Yes I act on my battery like it is at 54%. I know it is a mind game for me, but because I full-time in an RV - it works for us.

 

[Rocketman]

There is a YouTube on how to add some nuts and bolts and add fuses to a PowerIn.

If you want to light up the led’s on a distributor- you need a 5v power supply - there is also a YouTube showing the parts they used to do that.

Explorist life shows both.

 

[caymaanedge]

Managed a crappy photo of my setup. Rope is a pull string coiled up that I ran inside the R.V. for future use.
Going to add Cerbo and Touch this fall.
Thanks again for all the help.

 

[justinm001]

Managed a crappy photo of my setup. Rope is a pull string coiled up that I ran inside the R.V. for future use.
Going to add Cerbo and Touch this fall.
Thanks again for all the help.

Definitely just move the mppt to the shunt bolt.

 

[justinm001]

Unfortunately I don't think it does. It seems to only work if you have the Lynx BMS, not the shunt.

I think you're right. When I checked mine last it was green then all lights flashing red then back to green so idk what that means. Just got my 3rd inverter this afternoon so about to start moving everything to a new bay and recounting all nice and clean.

I have the smartshunt on my 12v and lynx shunt on my 48v. The smartshunt has bluetooth and seems better, although I HATE ve direct cables and superglue them. It's dumb the lynxshunt is more.

BTW I saw a guy use a powerin or distribution (can't remember which) and actually put the smartshunt on the end of the box and ran all neg battery wires to one side and all neg loads to other. Pretty genius. He used copper bracket to make the smartshunt fit between the lynx bolts.