question

peedee44 avatar image
peedee44 asked

BMS 12/200 with Balmar MC 614 voltage sense connection

Electric Schematic ver 1.jpg

Hello

I apologize for the last post with no question. this forum format is new to me. I will try to delete it.

I am setting up a new lithium house bank on my 44 foot cruising sailboat

there was a post about Balmar alternator charging cutting out early. the answer was to connected the alternator Regulator voltage sense wire to both the starting battery and the house bank. Is this really correct? I want to connect it only to the lithium house bank because the charging profile for lithium is more sensitive to voltage because the voltage is more constant than lead batteries.

Here is my system and I attached (i think) a drawing.

2x victron smart lithium 160 amphour house bank

victron smart 12/200 BMS

victron smart battery protect 220

Balmar 100 amp alternator with MC 614 regulator

400 watts solar with outback 60 amp regulator

Xantrex Freedom 2000 inverter charger


any other comments on this system are welcome


Peter



BMS
electric-schematic-ver-1.jpg (1.7 MiB)
2 comments
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

philiplyra avatar image philiplyra commented ·

Hello Peter,

Can you include link to the post you are referring to?

It seems a bad idea to connect sense wire to both Lead Acid and Lithium Battery. That would bridge the BMS, which would not be protecting your house bank anymore.

Philip

0 Likes 0 ·
jraelson avatar image jraelson commented ·
Hello; I am currently doing an almost exact same system as yours and am connecting my MC-614. What solution did you end up with? Thank you!
0 Likes 0 ·
4 Answers
peedee44 avatar image
peedee44 answered ·

thanks for the reply. It does not seem right to me either.


I am not sure how to link another question so here is a copy of it:

1644879647543.png
svgemini asked · Nov 19 2021 at 6:31 PM

Smart BMS 12/200 with Balmar MC-612 cutting alternator input


1644879647543.png (1.3 KiB)
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

svgemini avatar image
svgemini answered ·

The solution I came up with has been working for a few months now. I made sure the voltage sense wires were as short as possible for the AGM and Victron smart LiFePo4. I set the volage cutoff on the smart BMS to 14v and programmed the Balmar to be at the top end of voltages for the AGM while being in range for the LiFePo4.
Without having the voltage wires sensing both batteries the Balmar would try to dump full field into the AGM (sending 17volts) once the bms stopped allowing the LiFePo4 from getting charge. Now I get the LiFePo4 up to 14volts and then the start battery goes up to 14.3 like I want to and stays like that.

Hopefully that makes since.

1 comment
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

jraelson avatar image jraelson commented ·
On the Balmar MC-614 the voltage sense wire is one wore and one input. Did you then just combine two sense wires into 1 wire at the input on the MC-614?
0 Likes 0 ·
philiplyra avatar image
philiplyra answered ·

On my sailing boat I have installed Smart BMS 12/200 with 330Ah Smart Battery (and 12V lead acid start battery). Works fine.

My alternator regulator has a sense wire, and I found out it has to be connected to the "input" of the fuse and not to the Smart battery directly. If you connect it to the Smart battery, the Alternator will continue to deliver high current and Voltage (voltage drop 2V between input and battery) which results in BMS switching of due to overheating (and also too high voltage for lead acid battery).

1 comment
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

jraelson avatar image jraelson commented ·

I am confused about where you have the sense wire attached. Do you mean on the on the alternator input side of the fuse on the BMS12/200? Doesn't this just sense the alternator output?

0 Likes 0 ·
northcaptain avatar image
northcaptain answered ·

Same issue on my side with a 618. If i sense voltage on the start battery it stop charging. If i sense on the battery i go against Balmar recommandation. So what is the correct way to connect that sense wire ?

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.