Victron Bmv 700 setup for dummies

[Craig1]

Hi

 

No I'm not posting for dummies, I want some advice for myself and other dummies!

 

I've this Victron battery monitor, I've 4 x 110ah batteries (18 months old), I've 200W solar panel on the roof (well once they were 200w).

 

Think I did a factory reset on the monitor and want to set up again.  Any of you wise folk care to explain what I'm to do to re-setup?

 

I'm not after any complicated explanations here, nor any formulae, just tell me what to do if you would.  If I can save some money on diesel here that would be good!

 

I don't want to connect it to my phone, just nice and simple if poss.  I know someone will go on about Peukert but that's all way above my head.

 

Thanks guys for any help,

 

Craig

[Tony Brooks]

Sorry, but can't resist - RTFM.

 

I am going to stick my neck out. You only need to set it up and then keep attending to it of you want your % charged type scales to be even semi accurate. Getting your head round what you need to do now and then what you need to do regularly will be difficult.

 

The % charged type scale are well known for helping many, many new or inexperienced boaters to ruin their batteries by consistent undercharging. As you don 't want complicated explanations I will not explain why.

 

My advice:

 

Use amps, which will be accurate to decide when the batteries are more or less fully charged, stop charging at 1 to 2% of your battery capacity. This will do little to help with fuel consumption but try to do it at least once a week.

 

Use RESTED voltage to assess the state of charge. That is battery voltage with no load and at least an hour after finishing charging or after a moderate load has been put on the batteries for  short while.

 

12.7 to 12.8 volts - accept as fully charged.

12.5 volts -  assume half discharged

12.2 to 12,3 volts - stop drawing electricity and recharge ASAP.

 

Again as you don't want an explanation I will not explain why this varies form what you read elsewhere on the net.

[Tony Brooks]

I have come back to add that trying to save diesel when battery charging stands a good chance of costing you frequent new batteries. Every few weeks/months is not unusual for new, inexperienced boaters..

 

By the way, most rigid solar panels are guaranteed to still be providing 80% of their rated output after 25 years so your 200 watt panel should still be about 200 watts. What will have altered is your battery capacity and the longer you have left them partially discharged the lower the capacity will be. In your case they are very unlikely to now have a capacity of 440 Ah, it will be less, and that is one thing that complicates the setting up of the meter.

[PeterF]

Here are some possible settings to start with, but really, the BMV needs to be tuned to your system and batteries to work correctly, there are several videos on Youtube from Victron describing this.

 

Battery Capacity - 440 Ah (but as Tony above says, they may no longer have this actual capacity)

Charged voltage - this should ideally be about 0.2V below your absorption voltage so if you normally charge at 14.4V then set this to 14.2V.

Tail current - 1.5% - this means that when the charge current is less than 1.5% x 440 = 6.6Amps and the voltage is above 14.2V then it will go to 100%

Charged detection time - leave at default 3 minutes

Peukert exponent - leave it at the default 1.25

Charge efficiency Factor - 90%

Current Threshold - leave at default 0.1A

Discharge floor - 50%

 

Leave everything else at default.

 

The key things to getting them to show a bit more sense are the Charged voltage, the tail current and the charge efficiency factor. However, once again, I echo Tony's comments above, if the BMV is not tuned to your batteries then it can lie to you, so watching the voltages and currents is a good indication and the BMV gives you this data. I trust my BMV but I started with new batteries and spent time watching how the batteries charged to tweak the parameters.

[MtB]

7 hours ago, Tony Brooks said:

Sorry, but can't resist - RTFM.

 

 

To be fair though Tony, the manual is best part of half an inch thick and will take the OP at least a weekend to read and understand, if ever. 

 

On the other hand having shelled out the price of a BMV it seems a shame not to learn how to drive it! 

 

 

[Jen-in-Wellies]

7 hours ago, MtB said:

 

To be fair though Tony, the manual is best part of half an inch thick and will take the OP at least a weekend to read and understand, if ever. 

 

On the other hand having shelled out the price of a BMV it seems a shame not to learn how to drive it! 

 

 

 

To be even more fair, reading all the manual requires you to be fluent in English, Flemish, French, German, Spanish and Swedish. Easy for the typical polyglot Dutch user, but not so much for the average Brit, who can barely manage English. 😀

Edited December 8, 2022 by Jen-in-Wellies

[MtB]

23 minutes ago, Jen-in-Wellies said:

 

To be even more fair, reading all the manual requires you to be fluent in English, Flemish, French, German, Spanish and Swedish. Easy for the typical polyglot Dutch user, but not so much for the average Brit, who can barely manage English. 😀

 

I was saving that up for later, a moan about how the manual keeps chopping and changing language. And how one needs to be a polyglot to read and absorb everything it says. 

 

I really do think it was a bad decision for them to do that. The whole thing should be in English. 

[Jen-in-Wellies]

1 minute ago, MtB said:

 

I was saving that up for later, a moan about how the manual keeps chopping and changing language. And how one needs to be a polyglot to read and absorb everything it says. 

 

I really do think it was a bad decision for them to do that. The whole thing should be in English. 

The polylingual Victron manuals still beat the, at best, single page of machine translated Chinglish instructions you get with the cheaper sorts of electrical kit from EBay.

"Be assured not to press the button twice times as this may cause an occurance."

[MtB]

1 hour ago, Jen-in-Wellies said:

The polylingual Victron manuals still beat the, at best, single page of machine translated Chinglish instructions you get with the cheaper sorts of electrical kit from EBay.

"Be assured not to press the button twice times as this may cause an occurance."

 

And my fave, the classic from the old car handbook about 'use of the horn': 

 

"If a pedestrain hove into view blocking your path, at first use the horn to tootle him melodiously. If he take no notice, parp him with vigour."

 

 

 

Edited December 8, 2022 by MtB

[Craig1]

Thanks for all the advice.  I know the bmv is not going to be 100% accurate but it's some guide, so thanks for all your help.

[Craig1]

I've just read through this all properly, and wanted to Thank you again.  Tony, I'm glad to read what you say about the solar panel, that's great news.  

 

Peter, thanks for comprehensively answering the question, I've set the bmv up accordingly but appreciate what you and Tony stated, I won't get an accurate reading but I'll use the voltage and Amps for more accuracy.  I've a back boiler pump that's continuously running in the colder months, so that will confound the thing somewhat.  Tony you did pique my interest a bit despite me stating I wasn't interested in the complexities of it all - now I'm wondering about how to get that accurate voltage reading bearing in mind the running pump is always draining the batteries, as like you said, you read different figures on the internet about how low to let the voltage drop to.

 

Any takers?

[Tony Brooks]

44 minutes ago, Craig1 said:

I've just read through this all properly, and wanted to Thank you again.  Tony, I'm glad to read what you say about the solar panel, that's great news.  

 

Peter, thanks for comprehensively answering the question, I've set the bmv up accordingly but appreciate what you and Tony stated, I won't get an accurate reading but I'll use the voltage and Amps for more accuracy.  I've a back boiler pump that's continuously running in the colder months, so that will confound the thing somewhat.  Tony you did pique my interest a bit despite me stating I wasn't interested in the complexities of it all - now I'm wondering about how to get that accurate voltage reading bearing in mind the running pump is always draining the batteries, as like you said, you read different figures on the internet about how low to let the voltage drop to.

 

Any takers?

 

Turn the pump off for a few seconds, but probably not unless the fire in the stove is low. If it is a diesel or gas boiler and you are a bit slow the boiler will probably shut down for a while or reduce its output.

 

If you want to optimize the battery life I would rarely let the rested voltage drop drop below 12.2 to 12.3 volts. This is to do with minimizing the effective number of battery cycles because lead acid batteries have a defined number if cycles, often in the very low hundreds, so by never discharging below a true 50% depth of discharge you kind of double the cyclic life. This has nothing to do with loss of capacity cased by sulphation. You combat that by regularly getting the batteries close to fully charged and leaving them partially charges for the shortest periods possible.

 

[Craig1]

Thanks Tony, helpful as ever