Solar panels with battery monitor

Hello All - 

I am planning on installing two 190 watt solar panels on my IP 35.  I have a Link 200 battery monitor connected to a  Xantrex 100 amp charger/2000 watt inverter. The manufacturer of the solar (GoPower!) recommends connecting the solar wiring directly to the the batteries.  It seems to me that this would bypass the Link 2000, which monitors charging currents and amp hours used and available.  My question:  is there a way that it can be wired so the Link 2000 recognizes the amount of charge generated by the solar panels and therefore calculates accurate state of charge?

In order for a Battery Monitor (BMS)--any that I have seen--to work properly, nothing can be connected to the battery side of the shunt (which should be on the negative post).  This allows the BMS to see charge in and charge out.  Anything that connects directly to the negative post on the battery (or the battery side of the shunt) is invisible to the BMS, be it load or charge source.



Additionally, your solar panel(s) should run through a charge controller and not be connected directly to the battery bank.  PV panels will produce whatever voltage they produce.  That voltage may or may not bee what the batteries need for their current charge state.  To grossly oversimplify, your battery (bank) charge cycle will be:

1. Bulk:  as much current as possible at its current voltage (which increases as charge level increases)
2. Absorption:  constant voltage of about 14.4v until "fully charged" (when current accepted drops to about 2 amps)
3. Float:  a maintenance stage where the voltage is kept at about 13.2v.

The specific values change according to battery technology (Flooded Lead Acid vs. Absorbed Glass Mat vs Lithium), temperature, and manufacturer recommendations.  There's a bloody science to it that can get fairly complex, but the above is an 80%+ solution.

Thank you for this info and the diagram. So, this means that the positive wire from the solar would be attached directly to the battery and the negative wire would connect to the non-battery side of the shunt. Correct?

The solar package I am looking at made by Go Power! includes the solar controller.

Negative to non-battery side of the shunt.  Positive can go directly to battery positive.  Or you can run it through a fuse or breaker first if you want to limit the max amperage to your batteries.  I'm not sure there's a significant benefit from adding the fuse/breaker, but it does provide the ability to deactivate the solar charging.

Note that you could put the positive on the far (non-battery) side of the large, rotary switch.  If you did that, you could move the switch to "OFF" and it would totally isolate the battery.  In the illustration the only thing that would be impacting the battery would be the monitor.  The batter(ies) wouldn't be receiving a charge though (in the "OFF" position).  I don't know why one would want to do that, but some people say they close all their through-hulls when they leave the boat for more than a few hours.

One thing I don't like about that illustration is that it has hidden how the gray cable runs from the shunt to the battery monitor display.