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Tim D.
Jan 25, 2021, 1:14:32 PM1/25/21
to electrodacus
I have a SBMS120 and if I understand correctly it prevent DC loads from over-discharging a battery pack by disconnection the DC load side of the BMS's FETs.
How does the SBMS0 protect a battery back from being over-discharged? with AC loads I assume it just turns off the inverter, but how does the SBMS0 stop DC loads connected to the battery from over-discharge?
Dacian Todea
Jan 25, 2021, 2:20:13 PM1/25/21
to electrodacus
Tim,
For DC loads something like the Victron BP65 can be used. The BP65 is about $40 and can be controlled by the SBMS0 to disconnect small DC loads. Most people with larger systems only use AC from an inverter some will have maybe a 24V battery and then use a DC-DC converter for 12V devices and the DC-DC can have a remote ON/OFF (like the Orion-TR) then they can use that to disconnect the DC loads.
There are many solutions so it depends on the system.
On the SBMS40 or SBMS120 that Load+ output is to be used only with small non capacitive DC loads. So you can not connect an inverter there that will still need to have remote ON/OFF and be controlled by the EXT IO3.
Tim D.
Jan 25, 2021, 2:57:21 PM1/25/21
to electrodacus
Dacian,
Thanks for the reply
I'm looking at a small solar setup for an off grid cabin, the SMBS120 I have is being used so I was looking to buy a new one and see that they are no longer in production and that the SBMS0 has replaced all prior versions
I want to keep most things DC, Lighting will be DC LED lights and I will use DC appliances where possible to avoid the inverter losses
I'll look into the Victron BP65, would I connect the EXT IO3 on a SBMS0 to the "remote" port on a BP65? does polarity matter?
Dacian Todea
Jan 25, 2021, 3:18:49 PM1/25/21
to electrodacus
Tim,
Yes the EXT IO3 set as type 2 will control the BP65 and the polarity of the EXT IO3 no longer matters with last version of SBMS0 the v03d that is available now as this uses the Toshiba TLP172GM.
But for those reading this the older version of SBMS0 and all other SBMSxxx models the polarity is important as there is a build in diode In the Toshiba TLP187 used there so it can only open circuit in one direction and then the EXT IOx+ will connect to L and EXT IOx- will connect to H on the Victron BPxxx
There is a BP65, BP100 and BP220 available that is for 65A, 100A and 220A versions.
There is a BP65, BP100 and BP220 available that is for 65A, 100A and 220A versions.
Ken R
Jan 30, 2021, 9:27:51 AM1/30/21
to electrodacus
I have an SBMS120 I would be willing to sell. Never used, in original box. From Canada.
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