Old Magnum MS2812 and new Lithiums

[nsr1357]

it is not a dumb question, to be sure (I have a monopoly on "dumb" questions in most places) but the shunt is mounted in the right spot as victron directed, iboth leads are utilized and it is measuring voltage and aperage as the magnum unit is. as to "all", I am not sure what other ground you mean.

in any event, the shunt readings mirror the amperage and voltage readings that are also on the magnum 2812....the shunt is the only victron item in this set up, so the info via bluetooth is more than the magnum tells us, but even there, when it does indicate a 100% state of charge, the problems I am alluding to here, come fast and furious, nevertheless.

 

[nsr1357]

One more point! Just because the voltage is up does not mean the bank has soaked enough to be fully charged.

Soaking the battery does no harm at the voltage requested by the manufacturer.

A battery monitor is designed to keep track of state of charge. To set one up you must have a fully charged battery at startup! That means you should soak the batteries without using them for the time required for a full charge (this can be calculated). Personally I Just soak for a week to be sure.

Ultimately rock solid is obtained with properly setting things up!!!

i am not familiar with the term "soaked", but all eight batteries we have tested in this problematic area, have also been tested indvidually....by that I mean fully charged with a victron charger, one at a time, measured for current drops on their own to see if anything is amiss, and then measured again a day later or so, to see if there are any anomolies. every one of them specs out where it should.
other than the magnum panel, I do have, as mentioned, a victron shunt wired in per instructions (meaning, at the right place to it mirrors what the magunum panel is seeing and at last as it concerns voltage, amperage and it also gives, of course, a state of charge...which shows at 100%....but the batteries still do what they do and drop as they do, precipitously.
and the practical proof is, again, what happened last night off of shore power and how quickly supposedly fully charged batteries got below 13 volts with a modest load.
when all is normal..meaning shore power, panels contributing, etc.....the dishcarges come so fast, relatively speaking, that the charge cycle happens a half dozen or so times a day,

 

[nsr1357]

and after testing each battery, each of whic had been fully charged before we put each back into the array in line, showed perfect levels of charge. am I missing something?

 

[nsr1357]

If there was a draw taking the batteries down, it would show up on the shunt reading…it would show how many amps have been draw since last charge. I apologize for what might be a dumb question, but are ALL grounds running through the shunt?

hi,
i wanted to address your question about "all" grounds, and went to the manual (it appears this is connected the right way in my install):
per the manual:
"Connect the negative of the electrical system to the M10 bolt on the "LOAD MINUS" side of the shunt. Tighten the shunt bolt with a maximum torque of 21Nm. Make sure that the negative of all DC loads, inverters, battery chargers, solar chargers and other charge sources are connected “after” the shunt....."
I hope this is what you referred to and in this case, at least, they want all other ground connections "downstream", for lack of a better word.
anyway, thanks again for your time and help
ps the shunt is an ip65 500A flavor. it does give some discharge information but unless i am missing something it does not provide that data on any kind of daily basis as opposed to a cumulative one (from which, I would agree, one can calculate the differences (I have never done that but it is a good idea...thanks).

 

[Richpatty]

Is the Shunt a Victron Smart Shunt?

 

[nsr1357]

Is the Shunt a Victron Smart Shunt?

yes..just posted a model number and verbiage on connections, in particular, grounds.
thank you!

 

[Richpatty]

OK. As I have a Smart Shunt as well and it provides good info on what is happening at each moment. You should be able to see how many amps are moving across it and how much longer (usually in days) you have left.

 

[nsr1357]

OK. As I have a Smart Shunt as well and it provides good info on what is happening at each moment. You should be able to see how many amps are moving across it and how much longer (usually in days) you have left.

many thanks! it always shows a fully charged state to start with, but again, drops down very quickly along with the magnum panel.
in any event, I have a great tech person who is going to hold my hand on the phone this coming weekend, while we check the state of amperage and current on all the breakers to see if there is something draining this or somehow preventing a full charge, despite what the shunt says.
thanks again.

 

[Richpatty]

OK. Report back and let us know what you find.

 

[nsr1357]

OK. Report back and let us know what you find.

i intend to. c u all next week.