Help with 4s pack and victron 100/20 MPPT

[waiapasi2006]

Finally getting somewhere with my issue.
I had to remove the sensor and resolder them to the actual pins. So far I'm getting a reading.
Next,
Should I select from the standard parameters listed here?

Or adjust the values based on overkill's manual?

 

[42OhmsPA]

I would create your own profile then save it. I suppose you could load theirs then review it and tweak if needed.

 

[waiapasi2006]

I would create your own profile then save it. I suppose you could load theirs then review it and tweak if needed.

Sounds like a plan.

 

[waiapasi2006]

Finally got a load on after tinkering with this BMS.

 

[740GLE]

Only thing I’d change is turn off “balance only when charging”.

I use “charge under temp” at 5c, release at 7c just for a layer of comfort.

 

[waiapasi2006]

Only thing I’d change is turn off “balance only when charging”.

I use “charge under temp” at 5c, release at 7c just for a layer of comfort.

Will definitely do that. I appreciate the recommendation.

 

[waiapasi2006]

I'll add it here to help someone in need in the event they are in the same position as myself.


I appreciate everyone's input and collaboration.

 

[waiapasi2006]

Just an update. Added a 100 watt/ 5.3 amp solar panel to the MPPT. So far all is well. The battery is slowly being charged.

 

[waiapasi2006]

Curious question to ask . I was reviewing the state of charge in the BMS setting. I noticed the voltage per percentage is inverted with the number listed here.

Should I correct these?

 

[740GLE]

Yeah that’s not right, I’ve never trusted BMS readings for SOC, that’s what a shunt is for

 

[waiapasi2006]

Yeah that’s not right, I’ve never trusted BMS readings for SOC, that’s what a shunt is for

Now that I'm getting more into this endeavor...., I learn as I go. I just did a quick search before asking I and it seems the Victron shunt is the to go. I would use that for my permanent setup, but is there something else out there I can use for testing .... Like these? Or something you recommend...

 

[740GLE]

The 300a is newish and as long as you don’t foresee your system exceeding 300a it’s a great unit for the price, I picked one up just to monitor my DC bus, I have a 500a for my battery connections.

The best thing is the shunt can link via BT (VE.Smart) to your SCC and it assists the SCC reaching your charging voltage (it negates and losses from the SCC terminals to the battery terminals by sharing actual battery voltage to the SCC).

This VE Smart network is well worth the extra few $$ over other shunts.

Pretty soon you’ll have a nice multiplus inverter charger and a cerbo GX

 

[waiapasi2006]

The 300a is newish and as long as you don’t foresee your system exceeding 300a it’s a great unit for the price, I picked one up just to monitor my DC bus, I have a 500a for my battery connections.

The best thing is the shunt can link via BT (VE.Smart) to your SCC and it assists the SCC reaching your charging voltage (it negates and losses from the SCC terminals to the battery terminals by sharing actual battery voltage to the SCC).

This VE Smart network is well worth the extra few $$ over other shunts.

Pretty soon you’ll have a nice multiplus inverter charger and a cerbo GX

, I'm sure that's coming soon

 

[740GLE]

I started with a 100/15 SCC

Then snagged the 500a smart shunt.

Then came the 24v/3k multiplus, a Lynx bus bar, a raspberry pi running Venus OS.

This year I snagged a 300a smart shunt, a 100/50 SCC. Only thing next is more PV and maybe another 24v 280ah battery.

I’m going to have to get creative to justify more victron gear after this year.

 

[waiapasi2006]

The 300a is newish and as long as you don’t foresee your system exceeding 300a it’s a great unit for the price, I picked one up just to monitor my DC bus, I have a 500a for my battery connections.

The best thing is the shunt can link via BT (VE.Smart) to your SCC and it assists the SCC reaching your charging voltage (it negates and losses from the SCC terminals to the battery terminals by sharing actual battery voltage to the SCC).

This VE Smart network is well worth the extra few $$ over other shunts.

Pretty soon you’ll have a nice multiplus inverter charger and a cerbo GX

As of now, this box build is just a portable system I'm playing with. I plan on donating it to a old camper friend.... The max he might pull from there is a coffee pot and basic phone charging etc...

And yes, the way I see this little build going sets room for upgrade and updated devices for my permanent setup....one day.

 

[waiapasi2006]

So I just checked the SOC and I went from fully charged to 60% overnight with nothing connected to the box. Could it be that the Bluetooth has some sort of drain on there?

I will proceed and buy the shunt and take it from there as well to see what else can be tweaked.

 

[740GLE]

Did you correct the % errors you found?

If nothing was connected to the batter and prior voltages were close to 14v, you still have a close to fully charge battery, LiFePo voltage bleeds down when idle so a closely fully charged battery can have 13.3 next morning.

The SCC only draws a couple mA so it’d take days upon days to impact the SOC.

 

[waiapasi2006]

Did you correct the % errors you found?

If nothing was connected to the batter and prior voltages were close to 14v, you still have a close to fully charge battery, LiFePo voltage bleeds down when idle so a closely fully charged battery can have 13.3 next morning.

The SCC only draws a couple mA so it’d take days upon days to impact the SOC.

Yes, I adjusted the value to match the bulk voltage of the SCC which is set at 14.3v.
That is the max voltage I have set as the parameters in the BMS. Below are my numbers. Let me know if that somewhat makes sense. Or,should I adjust accordingly.

As of now, the battery is at full SOC.
I will run a capacity test once I can find a power load.
Please let me know.

 

[42OhmsPA]

Now that I'm getting more into this endeavor...., I learn as I go. I just did a quick search before asking I and it seems the Victron shunt is the to go. I would use that for my permanent setup, but is there something else out there I can use for testing .... Like these? Or something you recommend...

I've been really happy with my WonVon 600A shunt (the older model) but knowing what I know now I'd go with the smurf shit blue if I were just starting.

 

[waiapasi2006]

Did you correct the % errors you found?

If nothing was connected to the batter and prior voltages were close to 14v, you still have a close to fully charge battery, LiFePo voltage bleeds down when idle so a closely fully charged battery can have 13.3 next morning.

The SCC only draws a couple mA so it’d take days upon days to impact the SOC.

Correction, I do have a very small inverter connected 750w old dinosaur....but it is off.

 

[740GLE]

Correction, I do have a very small inverter connected 750w old dinosaur....but it is off.

If it’s off it shouldn’t draw anything, but it might.

 

[waiapasi2006]

I found my stash. Added the inverter with some 1/0 gauge wires. Fuse will be in tomorrow.
Almost there. I was able to pull a 1550 watt load for a few seconds before the inverter went in protection mode due to the small 120 amp BMS.
Pulled about 150+amp for that short period of time. So far so good. At half load with the heat gun, it stayed running with no issue.

 

[waiapasi2006]

I've been really happy with my WonVon 600A shunt (the older model) but knowing what I know now I'd go with the smurf shit blue if I were just starting.

 

[waiapasi2006]

Weird one here . Is there a reason why I'm not getting a charge?
Victron shows 5 amps coming in. The BMS states other wise. When I turn off the inverter, the charging starts. Also, I went from fully charged to 49% with a very minimal load.....

What's next for me to look at?

 

[740GLE]

So the charger has idle consumption. This almost looks like 90w, which is absolutely horrible.

If you turn off the SCC(no PV coming in) and check the BMS you’ll see the total idle consumption of having the inverter just generate 120vac even with not powering any actual devices.

For reference my cheap WRLZB reliable 1500w psw inverter has 7w idle consumption.