Victron Battery Monitor Install

[golfarch]

Great question. I erroneously used 20 hr for capacity instead of 90ah.

How did I get two college degrees?

[Rocinante]

What's the actual voltage at the battery terminals?

OTOH, sounds like that technician needs to come back with an ammeter, among other things, to figure out what's going on and get it properly sorted.

Also - when you refer to hours remaining, do you mean amp-hours? That number didn't sound right either.

[golfarch]

Larry:

I reset the monitor to 90 ah and the entire system is functionin gperfectly.

With 0.80 A usage it now indicates that I have 3 days and 5 hours! That's better.

Wrong capacity set everything into 'helter skelter'. Now have proper readings.

Thanks. Very Much.

[golfarch]

I reset the monitor to 90 ah verses 24 and the system is now reporting proper numbers.

The wrong 24 ah capacity was wrong. It was not reading anything properly. The batteries were not at 36%. They fully charged in less than 2 hours and the time remaining now indicates 3 days and 5 hours with 0.80 A usage. Much better.
Thanks.

[lsbrodsky]

Yeah, but if you have 2 of those batteries in parallel, you have 180 AH of capacity and you do not want to draw them down to more than 90AH left, 50%.

Larry

[lewster]

The BMV-702 should be set for your total battery capacity. I would also check the 20 hour rating on the battery label, as most Group 27s have seen are rated at 100 amp/hours.......giving you a total of 200 amp/hours of capacity.

This is the number that should be programmed into your BMV-702.


Lew Farber

[golfarch]

Thanks:

I should reset to 180 ah?

[lewster]

You should determine the EXACT battery capacity listed on the battery label and multiply this number by 2 as your Group 27 batteries are 12VDC and the amp/hours of each battery is additive when connected in parallel.


Lew Farber

[golfarch]

Installed new batteries and now getting two different readings at the battery terminals with converter charging; 14.01 left side 12.60 right side. I will monitor and see what happens as the day goes on.

[Rocinante]

Yikes! I'd check the connectors between your batteries for resistance to see whether something is awry.

[golfarch]

Originally Posted by Rocinante

Yikes! I'd check the connectors between your batteries for resistance to see whether something is awry.

Rocinante:

I had a breakthrough!

There was positive and a negative wire attached to the right side battery relay breaker. We removed the black wire and just kept the red connected to the relay breaker because the opposite side of the relay breaker had a red wire going to the right side battery. The right side was not getting an equal charge from the converter. Now, for the first time in 4 years, both batteries are getting an equal charge! See attachment Victron Battery Monitor Screenshot.

We now have a black wire that we need to determine its proper location.

The Tech will be over on Tuesday to determine where it should go. I will monitor the batteries after I unhook the shore power today and start the refrigerator and turn on some lights to see how the batteries and the Victron Monitor perform.

Thanks for your support and interest in this 4 year issue.

[lsbrodsky]

I am puzzled by your response....I have a schematic of that circuit for my trailer. The relay is basically a switch between the battery bus and the DC distribution panel. The batteries are paralleled in the battery box, not at the bus.
My schematic does show a black wire to the battery bus for the 7-way tow vehicle charging wire. Electrically, that is the same is the battery input side of the relay. It might be the case that your trailer has the tow vehicle charging wire connected at the relay instead of the bus bar.
Larry

[golfarch]

That can be right. I had a new 7-way tow vehicle wire installed by Camping World a year ago and they probably made the incorrect connection. That also gives me a clue as to where the black wire goes! It may have been erroneously attached to the wrong connection. I will pass this on to the Tech on Tuesday.

Thanks for the insight.

[Rocinante]

Best of luck, glad you found whatever seems to have been causing the issue. What you describe sounds like it should have caused a dead short, will be quite interesting to see what the tech says when they take a look. I'm no expert, FYI - just thinking out loud, and could easily be mistaken or confused.

[golfarch]

I have a new Screen Shot after letting fridge and light run for about 16 hours. It appears that the batteries are functioning rather well. At -1.40A, the batteries would have 3 Days & 8 hours left. Seems realistic. Definitely many time better than my usual 1 day max!

[Rocinante]

Sounds awesome, congrats on finding and debugging the issue. Now we're gonna have to go get one of those Victron monitors to figure out where the power's going in our own system.

[NoResults]

Now that I have the battery monitor I am not sure what to believe. It reads after I night of light use 12.16V but 87.9%.

As far as what I have found this should be about 50%.

Am I missing something. Dave

[Brav]

Originally Posted by NoResults

Now that I have the battery monitor I am not sure what to believe. It reads after I night of light use 12.16V but 87.9%.

As far as what I have found this should be about 50%.

Am I missing something. Dave

We're there any loads on the system when you read it in the morning?

[lewster]

Originally Posted by NoResults

Now that I have the battery monitor I am not sure what to believe. It reads after I night of light use 12.16V but 87.9%.

As far as what I have found this should be about 50%.

Am I missing something. Dave

Are you certain that you programmed the BMV-702 with the proper amount of amp/hours that match your battery bank? The default setting is probably not a match to your actual capacity.

[NoResults]

The only load I had was the refrigerator. My batteries are about 4 months old. I believe I programmed them at 140 amp.

They are interstate 24 OEM batteries that were replaced by the dealer about 4 months ago.

Thanks all