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carolion avatar image

BMV712 correct settings for Lead carbon batteries

Can someone please help me with the correct settings for my BMV712
I have 24 x 600AH REX Lead Carbon Nevada batteries connected and 2 x 5000W inverters.

It was initially installed incorrectly and I have since rewired it, but now need to reset the settings so it works as it should.

Thank you so much
Caroline
P.S I have no idea about alarms etc either, complete solar noobie

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2 Answers
alan avatar image
alan answered ·

Have to assume spell check has altered a bit here.

24 x 2v 600Ah Narada REXC cells I am going to assume.

By the operation manual here https://drive.google.com/file/d/1y2pHf7MO5fAidDebQH8VqKAnv78IIDdq/view?usp=sharing

and the data sheet here

https://en.naradapower.com/upload/at/file/20190118/1547778402112657831D.pdf


Change from "Equalise" (cyclic) charge to float is <5ma/Ah so for 600Ah tail current is. 3A or 0.5% (This may be a little optimistic if you have constantly varying loads on the system, in that case I would try something like 2%)

Peukerts Exponent calcs out at 1.08

For these cells in a 48v bank I set charged voltage at 53.8v to allow for temp compensation in a hot climate.

Charged detect time 5mins

Efficiency factor, manual alludes to 105% recharge to full capacity which works out at 95% however I have found this is a bit optimistic. So set it at 90% and monitor.


I would also be checking your charge voltages and temp compensation settings in your system

For cyclic use a 48v bank.

Absorption is 55.2v

Float 54v

Temp compensation is -0.120v/c

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wildebus avatar image
wildebus answered ·

Just an initial comment ... you said "I have 24 x 600AH REX Lead Carbon Nevada batteries".

You have the the Battery Capacity set at 600Ah on a - I presume - 48V system. Be worth comfirming what battery setup you have as I doubt the BMV battery value is correctly set (I am guessing that should maybe be 3600AH? 24 x 12V 600AH batteries in a 48V setup?)

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