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Dosheimer avatar image
Dosheimer asked

LiFEPO4 and windgenerator regulator problematic?

Hi!
I am evaluating a change from 4x100Ah AGM to min. 200Ah LiFEPO4 on my cruising sailing yacht in the near future (I have in mind to keep the existing separate 75Ah AGM starter battery) and have some uncertainty withmy existing windgenerator (and also with my sterling A2B).

As far as I am reading so far one or more BMS controlled battery protection relays like the BP220 battery protect or a cyrix li charge (what is the difference?) shall be installed between the chargers and the LiFEPO4 battery bank to protect the batteries from overloading and low voltage etc.

I have the following loading sources already included in my setup:
- 120A inverter-charger Victron MultiPlus 12/3000/120/50, reduced to 50% in settings
- 50A solar charger (Victron MPPT 50/100, solar panels connected: 600Wp)
- 60A wind/solar charger (Silentwind hybrid MPPT charger, installed: wind generator + 310Wp solar panels connected), LiFePO4 charge possible
- 115A alternator (Mitsubishi A003TR0091ZT 115A) connected to Sterling A2B Pro Alt C 130A (LiFePO4 charge possible)

I assume a battery protect between the MultiPlus and the battery would not be necessary, because the multi directly can be connected to the BMS via VE.direct and therefore shut down by BMS in case.

What I saw in the silentwind regulator manual is that the hybrid regulator can be destroyed in case it´s disconnected from the battery when still connected to the wind generator and/or solar. So do I have to decide what "shall be destroyed"? So if I decide for a battery protector relay I decide to protect the batteries, but would risk the silentwind MPPT charger?

Quite the same uncertainty I have with my sterling A2B.

Beside the above mentioned I have the following components already installed in my setup:
- BMV712 battery monitor
- VenusOS on Raspi4 with Node Red (Multiplus, BMV712 and MPPT 50/100 are connected)
- VE.bus smart dongle
- battery sense

Would be great if you could give me some hints, thank in advance!

Battery Protect
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4 Answers
rona avatar image
rona answered ·

You could wire your wind regulator output directly to the engine battery .Then install cyrix Lict relay between engine and house batteries and set the regulator charge profile for Li.

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Dosheimer avatar image
Dosheimer answered ·

Thank you for you response Rona. Interesting, I will check the cyrix.
Maybe I would have a problem with the SOC monitoring in this proposed setup as the power from the cyrix would not be considered in mesuring of the service batteries, but I need to think twice about that.

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Dosheimer avatar image
Dosheimer answered ·

(I am speaking about the shunt connection in this context)

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Dosheimer avatar image
Dosheimer answered ·

More and more I am thinking that the Smart BMS 12/200 would be the solution for me (I will take out my Sterling A2B Pro Alt C 130A in that case).

What if I would connect all my charging sources to one single "charging" busbar.

This charging busbar I would connect with the starter battery and the alternator/starter battery port of the Smart BMS 12/200. All charging sources I would put to LiFePo4 (14,2V) and could still use my 75Ah standard AGM as the starter battery in that case right?

Does thi smake sense and what about my multiplus inverter/charter in that case.

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