HELP, Please ! What Have I Missed ?

[Highland Fling]

Just connected up a Victron Energy BMV 602S battery monitor and am a bit confused - everything seems to work fine EXCEPT I don’t see my batteries being charged by the engine/alternator. This charges the Engine Start and the House batteries via a Diode Isolator Block.

I took the negative return from the output side of the 100A fuse that is after the negative cut off switch to the shunt then took a new wire from the shunt back to the output terminal on the fuse.

I wired my fridge and freezer return connection direct to the load side of the shunt (previously it was a direct connection to the battery switches) with a C/B of course.

I wired the negative side of my solar to the shunt.

I can see the solar output AND when I switch on the F/F AND any other electrical load at the main panel I can see the discharge amps.

But on staring the engine while I can see the battery voltages change to a plus 14V figure (the 602 monitors two sets of battery voltage House and Engine Start with two separate sense wires) I don’t see the output of the alternator charging the batteries.

Every so slightly fumumoxed

What have I done wrong missed?

HELLLLLLLLLLLLLLLLLP :-)

[goboatingnow]

Probably you haven't the spa hunt for the victron in the negative line as the last thing before the battery negative terminal. In essence the side of the shunt connected to the battery negative terminal must be the Only connection. Otherwise that circuit will not be recorded by the monitor. If you are monitoring both banks you have to have two shunts. Often the starter battery is just voltage monitored

Dave

[Highland Fling]

The shunt is the last thing in circuit I took off the neg wire from the isolation switch which has a 100A fuse in series. This lead (the output of the fuse) went to the boats neg buss bar. I led that wire to the load side of the shunt then brought the other side (the battery side) of the shunt back to that terminal on the 100A fuse. So the circuit is bat neg to the isolation switch then the fuse then the shunt then the boats negative buss bar. Which is correct as i understand things.

I see ALL my loads and i see my solar input (the neg side of the output of my MPPT controller is connected to the load side of the shunt)

BUT somehow the Battery Monitor is not seeing or monitoring the main charge circuit.

EVERYTHING works APART from i dont see the batteries being charged from the alternator. so the battery monitor is only monitoring solar input and all the other outputs not the main battery charging


Yes i understand i am 'only monitoring the start battery voltage'.

[Maine Sail]

-Shunt should be the first thing off the house banks - battery post unless that fuse is your banks only fuse. Then it sould go - post, fuse, shunt, switch. The shunt should not be switched off or you won't capture parasitic loads. The device is intended to be "always on" except in an off season.

-Check to find out where your engine ground lands. It needs to land on the load side of the shunt as should the neg/ground for the second bank. It may land on the second bank and you've bypassed the shunt with the second banks negative wiring?

-If the alt is isolated ground find the neg wire and follow it back to where it lands.

-Unless your alt is inoperable this is most likely a case of a miswired shunt.

[DeepFrz]

A wiring diagram would help us diagnose your fault. In fact it just might help you diagnose your fault.

[Highland Fling]

Originally Posted by Maine Sail

-Shunt should be the first thing off the house banks - battery post unless that fuse is your banks only fuse. Then it sould go - post, fuse, shunt, switch. The shunt should not be switched off or you won't capture parasitic loads. The device is intended to be "always on" except in an off season.

-Check to find out where your engine ground lands. It needs to land on the load side of the shunt as should the neg/ground for the second bank. It may land on the second bank and you've bypassed the shunt with the second banks negative wiring?

-If the alt is isolated ground find the neg wire and follow it back to where it lands.

-Unless your alt is inoperable this is most likely a case of a miswired shunt.

Alternator NEG was going to the Battery NEG switch thanks. Now on the load side of the shunt and everything is hunky dory. I needed to swap around a few conductors to have a 2 AWG wire going in and out of the shunt as it was now part of the engine start circuit.

thanks again

[Maine Sail]

Originally Posted by Highland Fling

Alternator NEG was going to the Battery NEG switch thanks. Now on the load side of the shunt and everything is hunky dory. I needed to swap around a few conductors to have a 2 AWG wire going in and out of the shunt as it was now part of the engine start circuit.

thanks again

Glad it worked out! Wiring shunts is very easy but often difficult too.

[Highland Fling]

Originally Posted by Maine Sail

Glad it worked out! Wiring shunts is very easy but often difficult too.

AH HA BUT.....................

Today we put on the Rutland 913 Wind Generator with a HRDi controlller

Connected the pos output of the controller to the pos of the house batteries and the neg output to the load side of the shunt and while the HRDi sees input from the WG (though this is a little unclear as to what the HRDI display is actually showing {input from the WG AND output to the batteries} {or just input from the WG} (the next line of the HRDi display is AH into the battery with what looks like an hourly total {incrementing in one hour chunks?} only) the VEM does not show any input to the batteries from the WG. WG is whirling round quite merrily 2A and more generating and nothing shown on the VEM.

MORE FUN

[svBeBe]

David,

I see you have solar and victron MPPT and had a problem which you worked out.

I had 3 each Kyocera 135W solar panels (17V) installed, in series, to a Victron 75/15 MPPT (this 75/15 is a loaner which will be replaced with a 75/50 which is on order). Remember I have a 24 volt house bank.

PV terminals on the MPPT to the 3 series-wired 135W solar panels
BATT + to the 24V + post
BATT - to the input side of the shunt
Nothing wired to LOAD

Settings:
No bridge: BatteryLife algorithm set on MPPT

Other available settings are:
Bridge between pin 3 and pin 4: conventional (see 1.2.1.)
Low voltage load disconnect: 11,1V or 22,2V
Automatic load reconnect: 13,1V or 26,2V

Bridge between pin 2 and pin 3: conventional (see 1.2.1.)
Low voltage load disconnect: 11,8V or 23,6V
Automatic load reconnect: 14V or 28V
In ideal conditions LINK 10 shows 25 amps going to batteries.

I was amazed how many amps I was getting which was up to 160 amps/day (24V). The LINK 10 showed batteries at 100% (amps) by mid afternoon, but over 3 days without running battery charger/genset, the voltage dropped from 25.8v to 24.2v, still showing 100% charged (amps). I ran the generator for 2 hours to fully charge the bank (volts).

Shut wiring attached.
Photos of arch: S/V BeBe: BeBe has been mutilated!!

Can you explain what is happening?

Judy says hi.

Bill
BeBe, Amel 53

[svBeBe]

Originally Posted by svBeBe

David,

I see you have solar and victron MPPT and had a problem which you worked out.

I had 3 each Kyocera 135W solar panels (17V) installed, in series, to a Victron 75/15 MPPT (this 75/15 is a loaner which will be replaced with a 75/50 which is on order). Remember I have a 24 volt house bank.

PV terminals on the MPPT to the 3 series-wired 135W solar panels
BATT + to the 24V + post
BATT - to the input side of the shunt
Nothing wired to LOAD

Settings:
No bridge: BatteryLife algorithm set on MPPT

Other available settings are:
Bridge between pin 3 and pin 4: conventional (see 1.2.1.)
Low voltage load disconnect: 11,1V or 22,2V
Automatic load reconnect: 13,1V or 26,2V

Bridge between pin 2 and pin 3: conventional (see 1.2.1.)
Low voltage load disconnect: 11,8V or 23,6V
Automatic load reconnect: 14V or 28V
In ideal conditions LINK 10 shows 25 amps going to batteries.

I was amazed how many amps I was getting which was up to 160 amps/day (24V). The LINK 10 showed batteries at 100% (amps) by mid afternoon, but over 3 days without running battery charger/genset, the voltage dropped from 25.8v to 24.2v, still showing 100% charged (amps). I ran the generator for 2 hours to fully charge the bank (volts).

Shut wiring attached.
Photos of arch: S/V BeBe: BeBe has been mutilated!!

Can you explain what is happening?

Judy says hi.

Bill
BeBe, Amel 53

All,

I found that the neg BATT wire from the MPPT to the neg side of the battery bank should not be where I located it on the shunt because this location will have a serious impact on the battery monitor reporting. In my case the battery monitor was probably reporting double the amount of amps going to the battery.

Fortunately, years ago, I met Nick (Jedi) on our circumnavigation. I sent him a private message regarding the above situation. His reply was: "Looking at the picture... you should relocate the negative wire from the MPPT away from the monitor sense leads. This will influence the monitor readings. Get a terminal for a big diameter fastener and connect it at the battery switch, on the side of the shunt. This means you can still switch off all power except keep solar maintaining the batteries."

Even though the large neg wire on the neg side of the shunt went directly to the position on the battery main switch that Nick suggested, the difference in battery monitoring was significant. Battery monitor had reported about double the actual amps from the solar array.

Hope this helps someone.

Bill
BeBe, Amel 53

[Maine Sail]

Originally Posted by svBeBe

All,

I found that the neg BATT wire from the MPPT to the neg side of the battery bank should not be where I located it on the shunt because this location will have a serious impact on the battery monitor reporting. In my case the battery monitor was probably reporting double the amount of amps going to the battery.

Fortunately, years ago, I met Nick (Jedi) on our circumnavigation. I sent him a private message regarding the above situation. His reply was: "Looking at the picture... you should relocate the negative wire from the MPPT away from the monitor sense leads. This will influence the monitor readings. Get a terminal for a big diameter fastener and connect it at the battery switch, on the side of the shunt. This means you can still switch off all power except keep solar maintaining the batteries."

Even though the large neg wire on the neg side of the shunt went directly to the position on the battery main switch that Nick suggested, the difference in battery monitoring was significant. Battery monitor had reported about double the actual amps from the solar array.

Hope this helps someone.

Bill
BeBe, Amel 53

As long as the MPPT wire was on the "loads" side of the shunt it should not have made any difference in the shunts performance. It is just measuring a voltage drop across it with the orange and white wires..

If however you turn off the NEG switch then, depending upon how it is wired, the battery monitor can not work properly as you've broken the "loads" connection and this would allow the solar to continue feeding the bank but it would not get counted if the monitor turns off with the NEG battery switch...... Ideally the monitor operates 100% of the time and there is no switch in the neg circuit that get turned off readily...