Tiny Home System 24v - Parts List Checking Advice please

Wanderingthomas · Jun 19, 2020

Hey Guys

Just looking for a little advice my components list, if you guys see anything that I'm missing or something that is incorrect. Cheers!

6x 400w SERAPHIM Panels 49v Open circuite voltage ( Total 2400W )
1x Victron MPPT 150/100
1x Victron smart battery sense ( for low temp cutoff communication to MPPT controller )

8x 280AH Lifepo4 Cells
1x 250A Daly BMS - Common

1x Giandel 3000w 24v Inverter

I think I'll be needing some Breakers as well? Any recommendations would be ace.

Cheers!

GMB · Jun 19, 2020

This is a schematic of my system and it's very similar to yours. Hope that helps.

Wanderingthomas · Jun 19, 2020

True, Thanks it is very similar, A few extra parts required by the looks of it. Cheers!

Wanderingthomas · Jun 19, 2020

GMB said:
This is a schematic of my system and it's very similar to yours. Hope that helps.

View attachment 15778

Can I ask few few questions?
1.What BMS you used?
2.Why do you have both the Battgo and BMV-712
3. Were you worries about the low voltage cutoff from the Giandel ? is it too low for Lifepo4?
Cheers!

GMB · Jun 19, 2020

Wanderingthomas said:
Can I ask few few questions?
1.What BMS you used?
2.Why do you have both the Battgo and BMV-712
3. Were you worries about the low voltage cutoff from the Giandel ? is it too low for Lifepo4?
Cheers!

1. Don't have a BMS yet. That's why I have the low voltage alarms and Battgo for individual cell monitoring. Bottom balanced and only charge to 27.2 volts. Batteries seem to really like the 3.4-3.3 per cell range at the top end and I have way more storage than I need. Will get a BMS in future, but haven't found one that fits my needs yet. ElectroDacus would be great, but doesn't work with Giandel inverters...
2. Battgo does individual cell monitoring and cell balancing, BMV 712 connects to the Victron app and the shunt provides AH in and out and it does a few extra things that the Battgo does not.
3. Not a fan of how low the Giandel is set for low voltage disconnect and cannot be changed, but my system is vastly overbuilt for my needs so getting that low seems very unlikely. In the event that it did, the low voltage alarms would go off before the inverter shuts down any how. I would of went with a Victron inverter if they offered something in the 4000 watt range at 24 volts - but they do not.

mandrews44 · Jun 19, 2020

Your battery bank is sized way too small for your panels.
Your panel will generate 500ah for a 24v system per day assuming your average is 5.5 hours per day.
If you had one more 8 cell 280ah battery, it would be closer to capacity. Otherwise, you will have to use 2x the power during the day as you do at night or only use 1/2 your solar potiential.

Wanderingthomas · Jun 19, 2020

mandrews44 said:
Your battery bank is sized way too small for your panels.
Your panel will generate 500ah for a 24v system per day assuming your average is 5.5 hours per day.
If you had one more 8 cell 280ah battery, it would be closer to capacity. Otherwise, you will have to use 2x the power during the day as you do at night or only use 1/2 your solar potiential.

Hi, Thanks, yep I know it's overkill, but The position of the Tiny is such that in winter it only gets 2hrs of direct light a day. Also the location has 1.5M average rainfall Per year, so plenty of cloudy days. Also I want to plan ahead for future expansion of the system

mandrews44 · Jun 19, 2020

Where is this location? Alaska?

Wanderingthomas · Jun 19, 2020

GMB said:
1. Don't have a BMS yet. That's why I have the low voltage alarms and Battgo for individual cell monitoring. Bottom balanced and only charge to 27.2 volts. Batteries seem to really like the 3.4-3.3 per cell range at the top end and I have way more storage than I need. Will get a BMS in future, but haven't found one that fits my needs yet. ElectroDacus would be great, but doesn't work with Giandel inverters...
2. Battgo does individual cell monitoring and cell balancing, BMV 712 connects to the Victron app and the shunt provides AH in and out and it does a few extra things that the Battgo does not.
3. Not a fan of how low the Giandel is set for low voltage disconnect and cannot be changed, but my system is vastly overbuilt for my needs so getting that low seems very unlikely. In the event that it did, the low voltage alarms would go off before the inverter shuts down any how. I would of went with a Victron inverter if they offered something in the 4000 watt range at 24 volts - but they do not.

OKey thanks for the info, Did you consider the Daly BMS, I think I'm happy with it's basic feature set. My only concern is the low voltage disconnect from the Giandel Low Voltage shutdown, which is set to 19v (2.375). From my understanding the Daly BMS will "Over discharge release voltage" at 2.5v. Then I'm assuming it will automatically restart, once voltage is high enough? Sorry for the million questions!

Wanderingthomas · Jun 19, 2020

mandrews44 said:
Where is this location? Alaska?

No Victorian Hi-Country, Australia. Though The Tiny is surrounded by a forest, and misses out on a considerable amount of sun because of this.

Wanderingthomas · Jun 19, 2020

Wanderingthomas said:
OKey thanks for the info, Did you consider the Daly BMS, I think I'm happy with it's basic feature set. My only concern is the low voltage disconnect from the Giandel Low Voltage shutdown, which is set to 19v (2.375). From my understanding the Daly BMS will "Over discharge release voltage" at 2.5v. Then I'm assuming it will automatically restart, once voltage is high enough? Sorry for the million questions!

OK, I think I've worked out a solution , I'm going to use a Victron BP-220 between the Battery/BMS and the Inverter/24v ELV system. That way it automatically disengage power at 21v, Then engage at 24V.

GMB · Jun 19, 2020

Wanderingthomas said:
OK, I think I've worked out a solution , I'm going to use a Victron BP-220 between the Battery/BMS and the Inverter/24v ELV system. That way it automatically disengage power at 21v, Then engage at 24V.

See this tread about using a Victron Battery Protect between an inverter and battery. You can also view the user manual for the battery protect online at Victron's site.

Why isn’t the Victron Battery Protect usable with a solar system?

Hello and thanks for looking... Will has stated to no longer use a Victron Battery Protect. I am wondering why and is there an alternative or is leaving that to the BMS good enough? Thanks. Shay

diysolarforum.com

An alternative is the Sterling Pro Latch R, but I would read through the user manual first as the programming is pretty daunting. I nope'd out of that option after reading it...but you may be more adventurous than I am. The user manual link is at the bottom of the page.

ProLatch R Programmable Latching Relay - 80 Amp

The ProLatch-R is designed to 'lock into position' and will not consume power once in position. The only current drawn is to run the internal software which amounts to about 0.5mA. This makes the ProLatch-R ideal for use with solar or wind sources.

baymarinesupply.com

Tiny Home System 24v - Parts List Checking Advice please

Wanderingthomas

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GMB

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Wanderingthomas

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Wanderingthomas

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GMB

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mandrews44

Solar Enthusiast

Wanderingthomas

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mandrews44

Solar Enthusiast

Wanderingthomas

New Member

Wanderingthomas

New Member

Wanderingthomas

New Member

GMB

Solar Enthusiast

Why isn’t the Victron Battery Protect usable with a solar system?

ProLatch R Programmable Latching Relay - 80 Amp

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