Battery Monitor vs Vessel System Monitor

[JK_Boston_Catalina310]

I posted before about the electrical system upgrade I am working on this winter. One of the items that I am going to include is a battery monitor. Initially I was planning on the Victron BMV-600S monitor. But when we chartered down in the BVIs in November, the boat we chartered had a multiple system monitor and I really liked it.

I looked up vessel system monitors and found the VSM 422 from Blue Sea Systems. It costs about $340 compared to $185 for the Victron. No small cost difference. But when you add the cost of a duel tank monitor and a bilge pump cycle counter, it gets to be very comparable.

So the question is, is it worth it?

 

[Tom J]

JK, does the VSM 422 come with all the sensors you'll need? If so, I'd say it's worth it. If you don't already have tank monitors, etc., it would be very cool to have everything on one panel.

 

[AnsleyS]

I would just like to put out one idea for your consideration as you think about upgrading your systems. That there is some value to having a number of units rather than just one unit. When you have a number of units and one dies you only lose a part of your functionality rather than everything together.

I have the Victron 602s battery monitor and I love it. It has made house and start battery management much easier. I also have a separate tank monitor which is OK but not as cool as the Victron.

 

[JK_Boston_Catalina310]

The VSM 422 would need to add the tank sensors (about $80 each) and can handle 3 tanks. So water, waste and diesel could all go on the VSM. The bilge sensor is included, as are the DC and AC monitors. I would probably just do the water tank for now. Although, having an idea of how full the holding tank is would be nice.

It was nice in the BVIs when the alarm went off when the batteries got to 12.5. I could still start the engine to charge. I could check both water tanks and the fuel too. The holding tanks were not connected on that boat because everyone just leaves them open (eww).

 

[JK_Boston_Catalina310]

I would just like to put out one idea for your consideration as you think about upgrading your systems. That there is some value to having a number of units rather than just one unit. When you have a number of units and one dies you only lose a part of your functionality rather than everything together.

I have the Victron 602s battery monitor and I love it. It has made house and start battery management much easier. I also have a separate tank monitor which is OK but not as cool as the Victron.

Sure, in key systems I agree with that principle.

I am installing a starter battery so that I have a house bank and a starter. Thanks to MS' help, I am doing it in a way that has great flexibility to allow both banks to start the boat or power the house load while keeping them isolated so a dead bank doesn't drag down both banks.

This is a convenience system. I don't NEED a battery monitor or a tank sensor. I have a multi meter. I can open the tank and look to see how full it is.

So on a smaller boat, I don't think I need to be worried about the "lose one, lose all" problem for a convenience system. I am more concerned about space.

But questions like this are why I posted the question, so thank you for offering it.

 

[Maine Sail]

The VSM is a good piece of gear but I am not sold on its precision or accuracy as a battery monitor. Blue Seas makes excellent quality products and has excellent customer support but the VSm is not a product I go to as a "battery monitor".

My frustration with the VSM lies in the fact that it does not allow for programming the batteries Peukert Exponent number. The designer, IIRC it was Wayne, never was able to give me a comfortable feeling as to how they calculate this internally or how the monitor compensated % charged with varying loads. Something about it being set by battery type IIRC. This is all well and good to have a "generic Peukert" but I have flooded batts with a Peukert of 1.15 and flooded batts with a Peukert of 1.59....

A 450 Ah bank with a 1.15 Peukert, running an average load of 6A becomes a 550Ah bank based on load.

A 450 Ah bank with a 1.59 Peukert, running an average load of 6A becomes a 982Ah bank based on load.

With a generic pre-selected Peukert there may very likely be counting errors beyond what you'd get with a Victron or Xantrex.

The Xantrex and Victron battery monitors allow for Peukert programming which helps make them about as accurate as a battery monitor can be.

 

[JK_Boston_Catalina310]

The VSM is a good piece of gear but I am not sold on its precision or accuracy as a battery monitor. Blue Seas makes excellent quality products and has excellent customer support but the VSm is not a product I go to as a "battery monitor".

My frustration with the VSM lies in the fact that it does not allow for programming the batteries Peukert Exponent number. The designer, IIRC it was Wayne, never was able to give me a comfortable feeling as to how they calculate this internally or how the monitor compensated % charged with varying loads. Something about it being set by battery type IIRC. This is all well and good to have a "generic Peukert" but I have flooded batts with a Peukert of 1.15 and flooded batts with a Peukert of 1.59....

A 450 Ah bank with a 1.15 Peukert, running an average load of 6A becomes a 550Ah bank based on load.

A 450 Ah bank with a 1.59 Peukert, running an average load of 6A becomes a 982Ah bank based on load.

With a generic pre-selected Peukert there may very likely be counting errors beyond what you'd get with a Victron or Xantrex.

The Xantrex and Victron battery monitors allow for Peukert programming which helps make them about as accurate as a battery monitor can be.

Thanks. That's what I suspected. Jack of all trades, master of none.

Guess I will stick to the original plan.

 

[Bob R.]

Has anybody installed a Philippi BCM battery monitor? They also make a Systems Monitor similar to the Blue Sea System monitor JK described. According to the specs, both monitors allow input of the Peukerts number for battery type and use a digital micro processor to transmit the current measurement at the shunt to the monitor. The monitor display is larger and easier to read. Specs appear to be as good, if not better than the Xantrex LinkPro and the Victron BMV 600S. List price is about $400 for a single bank monitor with a 300A shunt, but the distributor was offering a 20% discount at the boat show last fall. The electrical contractor I hired to do a battery and alternator upgrade this winter recommended the Philippi unit. He said he recently installed one on his boat to test the unit, but doesn't have much experience with it yet.

Bob R.

 

[Maine Sail]

The Philippi monitors are very nice. Do keep in mind that the extra shunts etc. get pricey if you want to add onto the system. I was installing one just last week in Puerto Rico that had multiple shunts. The Philippi's can do a LOT and are a very well engineered piece of equipment..