Victron Multiplus 12/3000/120 technical question

[SabrinaWorcs]

Hi, I have a Victron Multiplus 12/3000/120-16 on my boat.  When running the inverter with no shorepower and engine off, naturally the domestic batteries slowly deplete.  Eventually, the low battery warning light on the Victron starts to flash.  I assume this is triggered when the battery bank voltage drops below a certain value.  What I am not able to find in any of the documentation I have is what that voltage threshold is, and whether that broadly corresponds to (say) 50% discharge of the battery bank, or some other value (obviously I don't have a battery monitor fitted).  Can anyone help with that data?

 

Ultimately what I am trying to decide is how severe a condition that light indicates - does it tell me I am damaging the batteries with a deep discharge, or is it just saying "time to top up skip"?

 

The domestic battery bank is 5x110Ah, about 3 yrs old, and the firmware version on the Victron I think is 150 if that is relevant.

 

Thanks in advance

S

[WotEver]

1 minute ago, SabrinaWorcs said:

does it tell me I am damaging the batteries with a deep discharge

Yes. Severely. 

 

The low low voltage cutoff according to the manual is 9.5V. That is way below what is generally considered to be completely flat (10.5V). 

 

https://www.victronenergy.com/upload/documents/Manual-MultiPlus-3k-230V-16A--50A-(firmware-xxxx1xx)a-EN-NL-FR-DE-ES-SE.pdf

[Alan de Enfield]

I believe that it is default to around 10.5v but is 'user settable'.

 

10.5v is virtually death of a FLA battery so it is not advisable to use your inverter alarm as a method of controlling battery discharge.

 

Buy some method of battery monitoring system - it'll save you buying a new battery bank every few month.

 

 Add :

I have just had a look at my 'old' manual for the 12/2000/80 and it shows Inverter input voltage as 9.5v - 17v DC

If the alarm IS set at 9.5v then you are rapidly killing your batteries,

[WotEver]

http://www.cactusnav.com/merlin-smartguage-battery-monitor-p-11874.html?gclid=Cj0KCQjw3InYBRCLARIsAG6bfMQiThOPngl8TzBhUKlQ97ol4Ed6gCt5Bsr9xDeK_2_yGNPtZD72fhcaArN7EALw_wcB

[SabrinaWorcs]

20 minutes ago, WotEver said:

Yes. Severely. 

 

The low low voltage cutoff according to the manual is 9.5V. That is way below what is generally considered to be completely flat (10.5V). 

 

https://www.victronenergy.com/upload/documents/Manual-MultiPlus-3k-230V-16A--50A-(firmware-xxxx1xx)a-EN-NL-FR-DE-ES-SE.pdf

Thanks for the reply.  Yes, I have that manual, page 26 quotes the permissible input voltage range as 9.5V-17V.  I'm assuming at 9.5V it shuts down completely (low voltage light would then be permanently lit).  What I don't know is when does it start flashing.  Unfortunately my best guess is that it is also very low, but I wondered if anyone knew for sure.

29 minutes ago, Alan de Enfield said:

I believe that it is default to around 10.5v but is 'user settable'.  [do you have a reference for that or any info on how to set it?]

 

10.5v is virtually death of a FLA battery so it is not advisable to use your inverter alarm as a method of controlling battery discharge. [yes, I suspect you are right!]

 

Buy some method of battery monitoring system - it'll save you buying a new battery bank every few month. [again, I suspect you are right, that's the answer in the medium term, probably when I do change out the existing batteries]

 

 Add :

I have just had a look at my 'old' manual for the 12/2000/80 and it shows Inverter input voltage as 9.5v - 17v DC

If the alarm IS set at 9.5v then you are rapidly killing your batteries,

Thanks for the reply, couple comments/ questions above in [ ]

[mrsmelly]

2 minutes ago, SabrinaWorcs said:

Thanks for the reply.  Yes, I have that manual, page 26 quotes the permissible input voltage range as 9.5V-17V.  I'm assuming at 9.5V it shuts down completely (low voltage light would then be permanently lit).  What I don't know is when does it start flashing.  Unfortunately my best guess is that it is also very low, but I wondered if anyone knew for sure.

Hi

 

If you ever get anywhere near low voltage light coming on you are thrashing your batteries and either dont have enough capacity for your useage and/or are simply not charging properly and often enough. I would bet hand fulls of cash that your batteries are now cream crackered.

[Iain_S]

Agree with the above.

The low voltage warning light and invertor shut off system is designed to warn/shut off the invertor when it is in use supplying a reasonable load, and thus depressing the battery voltage. It should never be close to operating on a light load or standby/

[Dr Bob]

I have never let the low voltage light on our victron inverter flash. Far too low a voltage.