Battery Monitor Readings, not making sense. (1 Viewer)

[PhilandMena]

My battery monitor readings are not making sense? Anyone understand why these readings are being displayed.

 

[PhilandMena]

And here is the picture that filed to upload above.

 

[Lorryman100]

Your battery is nearing fully charged at 14.2v with the charger switched on. The charge rate of 2.1 amps dependant on charger is either a float or the amp charge rate is reducing as the battery charge reaches 100%. Is this on hookup or solar panels as on our MoHo with solar I get the same amperage when the batteries are nearing fully charged which drops down to around 0.20 amps at 14.16v on float.

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[denisejoe]

Thats a fully charged battery will slowly drop do you have solar panels

 

[PhilandMena]

Two solar pannels. Not on hook up. One connected directly to leisure batteries and other into Sargent system. I don't understand why I'm bulk charging full batteries and why controllers are allowing 2.1 amps to go to full batteries.

 

[Lorryman100]

Was there a draw on the 12v when you took the reading?

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[Boringfrog]

Two solar pannels. Not on hook up. One connected directly to leisure batteries and other into Sargent system. I don't understand why I'm bulk charging full batteries and why controllers are allowing 2.1 amps to go to full batteries.

What @Lorryman100 said.

 

[PhilandMena]

The readings come via a shunt and a Bluetooth monitor. Yes, at time of readings I had small inverter on charging phone but would expect solar panel controller to cancel this out provided enough power coming from panels and show a nil reading.

 

[denisejoe]

Was the 2.1 charge in the last charge it recieved ?
.

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[PhilandMena]

Was the 2.1 charge in the last charge it recieved ?
.

I do not understand what you state.

 

[denisejoe]

Solar is not charging so where is the charge coming from so its either the last charge that went in or a discharge if so you probably wont see a charge in until the battery voltage gets to 13 v

Joe

 

[PhilandMena]

Solar is not charging so where is the charge coming from so its either the last charge that went in or a discharge if so you probably wont see a charge in until the battery voltage gets to 13 v

Joe

OK ! I now understand what your saying. However, I beleive you to be wrong. Solar is charging,as this is the only source of electrical input going to the batteries. This is confirmed by the 2.1 Amp reading being black in colour, if it was a discharge from the battery it would be in red. Not sure about the logic behind your ' won't see a charge in until the battery voltage gets to 13 v' statement as the shunt and monitor provide readings of the battery condition in real time regardless of their charge status.
Thanks for the input though. I think I now understand why I'm getting this odd reading.

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[Lenny HB]

I would check the voltage with a meter and disconnect a terminal and check the current as well that will confirm if your reading are correct.
I don't see why you need two separate solar regulators also are the regulators the type that reduce to a maintenance charge of around 13.8 volts once the batteries are charged. There are a lot of regulators that stay at 14.2-14.4v permanently once the batteries are chargedd if one of your regulators is doing that it would explain your readings..

 

[PhilandMena]

I would check the voltage with a meter and disconnect a terminal and check the current as well that will confirm if your reading are correct.
I don't see why you need two separate solar regulators also are the regulators the type that reduce to a maintenance charge of around 13.8 volts once the batteries are charged. There are a lot of regulators that stay at 14.2-14.4v permanently once the batteries are chargedd if one of your regulators is doing that it would explain your readings..

My Sargent control panel more or less is identical to the shunt readings with the exception of how full the batteries are as expressed as a percentage. Before fitting the shunt a volt meter confirmed the voltage display on my Sargent control panel was bang on. The controller on my Sargent system and on my suitcase solar panel are set for less acid as all my batteries are connected to the Sargent system and charger which had performed flawlessly since new. I have also confirmed the two controllers act independently from each other and overall very happy with the set up.
I can only assume it has something to do with my inverter being in use at the time the reading was taken.

 

[PhilandMena]

The reason for two controllers is simple
One is factory fitted by Sargent. 10 amp max. The other factory fitted to the suitcase solar panel. A total of 245W which technically could blow the Sargent Controler otherwise I would have fitted another 125W on the roof. My Sargent system is not capable of handling a bigger controller.

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[andy63]

Interesting thread Phil. ..
I think we have discussed this set up before...
I'm not saying your system doesn't work as you are happy it does and i think martin ie funflair has a similar set up which works but I struggle to see how multiple charging sources can all work together.... I was always led to believe that the unit with the higher voltage would be the active source and unless the batteries were well discharged or heavily loaded ,thus pulling down the voltage the remaining sources would contribute next to nothing... or the primary source was supplying at max current and the batteries were capable of accepting more...

I'm assuming your reading of 2.1 amps charging current is the balance of your solar panels current after supplying whatever load you are running...
Andy...

 

[Lenny HB]

My Sargent control panel more or less is identical to the shunt readings with the exception of how full the batteries are as expressed as a percentage. Before fitting the shunt a volt meter confirmed the voltage display on my Sargent control panel was bang on. The controller on my Sargent system and on my suitcase solar panel are set for less acid as all my batteries are connected to the Sargent system and charger which had performed flawlessly since new. I have also confirmed the two controllers act independently from each other and overall very happy with the set up.
I can only assume it has something to do with my inverter being in use at the time the reading was taken.

Should have said before, inverters can play havoc with battery reading as you can get a lot spikes on the 12 volt supply.

 

[pappajohn]

Heres my slant on this......
The inverter and other bits are drawing 2.1amps from the battery but the solar is replacing it immediately cancelling the drain.
It will still show the battery as fully charged as, in effect, the solar is running the inverter not putting charge back in the battery.
Put on a higher load than the solar can provide and it will show a discharge.
The solar will provide what it can up to its max charge current, any excess comes from the battery.
Its the same with the onboard charger.
If it provides a max 15 amps and you draw 10 amps the battery will remain fully charged as the charger is providing the current, not the battery.

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[andy63]

The inverter and other bits are drawing 2.1amps from the battery but the solar is replacing it immediately cancelling the drain.

I don't get that John. .. the 2.1 amps is a charging current...ie into the battery as measured by an inline shunt... the only way you can know what the load current on the system is is to know the total current flow from the controller ... and subtract the 2.1 amps from it...( ie the 2.1 amps been the balance available for charging )
The current flow can only be one way at any time..
Andy.

 

[pappajohn]

Le

I don't get that John. .. the 2.1 amps is a charging current...ie into the battery as measured by an inline shunt... the only way you can know what the load current on the system is is to know the total current flow from the controller ... and subtract the 2.1 amps from it...( ie the 2.1 amps been the balance available for charging )
The current flow can only be one way at any time..
Andy.

No, the shunt shows current passing though it, it matters not where its going....in this case its powering the inverter.
Lets try a different example .....

Stick a straw in a full glass of water (battery), now put the glass under a running tap (charge current) and drink the water (load) through the straw at the same rate as the tap fills it......does the glass (battery) empty (discharge) or overflow (overcharge) ?

No, so the glass (battery) is a constant....only the tap and straw are doing any work.

 

[andy63]

No, the shunt shows current passing though it, it matters not where its going....in this case its powering the inverter.

cheers John, ill have a think about your example , but the problem I have atm is the shunt is capable of showing the direction of current flow... or at least the one I have wired to a ppm does.. its either a charging current or it shows as a negative value to indicate a discharging current..
andy

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[andy63]

OK I've had a think lol..
Your sinario fall down in my mind because the shunt should be measuring everything going in to or out of the battery...
In your eg the tap is filling the glass and the straw emptying it
If the tap was also connected to the straw and the straw had a t piece supplying the load then any excess water would fill the glass and if the draw was excessive then the glass/battery Would make up the difference... ie showing as a discharge from the battery...
Someone can tell me where I'm wrong ,but a shunt measures current by measuring volt drop across a very precise resistance so the circuitry in a pmp is capable of telling which end of the shunt is + relative to the other and therefore the direction of current flow.
That's my thinking...
Andy.

 

[pappajohn]

Depends were the shunt is though...
between solar and battery it cant ahow a discharge current....unless the solar is back feeding
Between battery and load it cant show a charge current. ..unless the load changes (motor to a dynamo maybe) to charge and put a current back into the battery.

 

[PhilandMena]

Wow! Love all this but clearly beyond my electrical competency. I can confirm the shunt is correctly fitted. I sought detailed guidance from the dealer who sold it to me who walked me through the simple wiring instructions. In essence, it's fitted between the two leisure batteries. The inverter is connected directly to one of the two L batteries. Before I fitted the suitcase solar panel, I switched all services off and then took the reading from the shunt. I then connected the suitcase solar panel and the amp reading almost doubled and I assume the two controllers were working together to deliver what ever was being called from the batteries. I have even seen both cab and leisure batteries being fed independently at the same time from each solar panel. Not sure how this works or why but very happy that it does.

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[andy63]

Depends were the shunt is though..

well its normal to place the shunt so that all connections made to the battery (both the load and charging sources ) go through it, otherwise whats the sense..?
if you didn't the readings in terms of battery state would be meaningless...
extra shunts can often be placed in other lines like the alternator, solar (if it doesn't already show the current flow on the panel ) in fact any line you want to measure the current flow on but the decent gear I've looked at charge a fair bit for additional shunts..

Between battery and load it cant show a charge current

but it can if the charging source is also connected at that point... thats what I'm saying.... the shunt will show either a charginging current or a discharge current
andy

 

[funflair]

We need a drawing phil, get your pen to paper and then just post us a photo of it.

Martin

 

[stevec]

But for a proper charge monitor you should be filling the glass through the same straw! The shunt should be the only connection to the battery. All charge and load connections should be done at the other terminal of the shunt.

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[pappajohn]

But for a proper charge monitor you should be filling the glass through the same straw! The shunt should be the only connection to the battery. All charge and load connections should be done at the other terminal of the shunt.

Now that makes sense.
For some unknown reason i was thinking the charge sources were connected to the shunt outboard connection and the hab electrics connected to the battery/inboard end of the shunt....which would only show charge, not drain amps.
maybe i need a more sleep.

 

[andy63]

But for a proper charge monitor you should be filling the glass through the same straw!

thats what I said

In your eg the tap is filling the glass and the straw emptying it
If the tap was also connected to the straw and the straw

andy

 

[pappajohn]

thats what I said

andy

Yeah, but stevec said it much more eloquently

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