Recommendations - Wireless Battery Monitor and Battery Test

[Dcsqatar]

Hello again. I posted a month or so with concerns about my batteries. Since then I have listened to a lot of helpful feedback and gotten some education (Pacific Yacht System YouTube videos are particularly good). I have decided that through ignorance, I likely loaded my AGM house batteries excessively (below 50% capacity) while using inverter to regularly make a pot or two of coffee and heat up some things with the microwave, on top of more essential power users like refrigerator, etc. Therefore, my batteries, although 27 months old and maybe 60 cycles, have likely lost capacity. I took some data along the way, and when looking back, my inverter tripped on low voltage (< 11v I think) at least 5 times, and I frequently left anchorage after 2 days with house bank voltage of 12.4v.

So having learned some lessons, I am seeking advice on:

1. Should I get the Victron Smart Shunt (presumably 500A is sufficient for my NW Edition R29S) or stick with a wired version? I do not particularly want another gage, and like the idea of data on my phone (and also no gage wires to run). However, a number of reviews claim to have issues with Bluetooth range and inability to store/trend performance data if phone is not connected.

2. Is there a proven way to determine the state of damage (or power capacity) of my house AGM batteries? Previously I was told to load test them, which I did and all four were good. However, since then I have determined that load testing is appropriate for starting batteries, as it determines available short duration amps, but is not insightful relative to deep cycle battery health. Ranger techs suggested putting a large load on fully charged batteries and then seeing if the voltage afterwards settles out to a high enough level. I did this (3 minutes on microwave on high). Voltage dropped to a low of 11.7v as shown on the inverter, while all the while 12.3v on the analog Panel meter. Voltage recovered to 12.8v after test, which Ranger suggested was indicative of good batteries. Yet I still have problems.

Thanks to anyone who provides some advice!

 

[Submariner]

So having learned some lessons, I am seeking advice on:

1. Should I get the Victron Smart Shunt (presumably 500A is sufficient for my NW Edition R29S) or stick with a wired version? I do not particularly want another gage, and like the idea of data on my phone (and also no gage wires to run). However, a number of reviews claim to have issues with Bluetooth range and inability to store/trend performance data if phone is not connected.

2. Is there a proven way to determine the state of damage (or power capacity) of my house AGM batteries? Previously I was told to load test them, which I did and all four were good. However, since then I have determined that load testing is appropriate for starting batteries, as it determines available short duration amps, but is not insightful relative to deep cycle battery health. Ranger techs suggested putting a large load on fully charged batteries and then seeing if the voltage afterwards settles out to a high enough level. I did this (3 minutes on microwave on high). Voltage dropped to a low of 11.7v as shown on the inverter, while all the while 12.3v on the analog Panel meter. Voltage recovered to 12.8v after test, which Ranger suggested was indicative of good batteries. Yet I still have problems.

1) I'd recommend going with the BMV712 Battery monitor, with the gauge. It should not be installed near the helm. Somewhere aft, closer to the batteries so the cable run isn't as long. The gauge is also nice for others in the boat to see. The gauge also will alert. It'll beep for high and low voltage, for example. If all you have is your phone with the Smartshunt and no gauge you would have to open up the Victron app to see those alerts. If you don't look at it often on your phone, you would miss those alerts. One issue with this, I've found... the frequency/pitch of the alert is outside of my audible hearing range. I literally can not hear the alerts at all. (Too much time in the engine room on a Submarine). But my wife hears it loud and clear and tells me. Also, the gauge will illuminate when it's alerting. So when I walk down to the boat and open the door, the first thing I do is look at the gauge. If the screen is lit up, I know it's alerting and will open up the app on my phone to see the details.

2) The only way I know of to test deep cycle batteries is to actually use them. With a battery monitor, it's easier to tell their usefulness. I would sit on the boat, disconnect from shore power, and use the boat. As consumed amp-hours increases, voltage will drop. I destroyed my pair of factory AGM batteries through too many excessive discharges (not having a battery monitor).

When I installed the battery monitor I did this test (disconnected from shore power with fully charged batteries and just ran some stuff on the boat. The radio, chartplotter, etc... Normal loads, like, 10 amps total or less). I got to like, a -4 amp-hours consumed in 30 minutes and voltage went from 12.8 to 10.5. The Garmin chartplotter alerted "Low voltage 10.5volts...". I performed this test on each of my two house batteries, separately. (jumperd out a battery). I got the same result on both batteries. 30 minutes of runtime from 12.8 to 10.5 volts. The factory batteries are 110Ah, they should be able to go safely down to 50% SOC which would be -55Ah consumed for each battery you have. (-110ah for a pair of them). That's how I knew it was time to go shopping for new batteries.

 

[Chimo]

I recently replaced our batteries and went with 3 x Lifeline AGM and an Optima for starting. I also had installed the Victron smart shunt as I didn't want to add additional wiring or a gauge. I'm pleased with the result and experience over the last couple of trips. Of course it is a new toy so there's a temptation to watch the app on the phone or iPad more than perhaps is necessary. The smart shunt does monitor the starting battery voltage separately. I will say that I have learned a lot about the demands and charging of the boat's systems so it was money well spent. A couple of observations:

I have a switch to combine the thruster battery with the house batteries when I'm on the hook. When I do that I have to remember to change the setting for the total battery capacity or the SOC readings will all be wrong. Of course I then have to remember to change back to the two battery reading when I head home. The same would apply to the gauge unit.

The SOC seems to be a simple calculation of Ah consumed/nominal capacity. Whether the takes into account the actual state of the batteries as they age by calculating the voltage drop compared with load imposed I will have to wait and see. The previous writer gives a good approach to estimating battery condition and it would work with either Victron solution. I guess that eventually I may be back to estimating actual SOC based on no load voltage after a decent interval.

I do set the alerts on the smart shunt, actually at 60%, but I'm keeping an eye on consumption better these days and I don't want to get anywhere close to that. There's good information on the number of cycles possible and the relationship with depth of discharge. These batteries are expensive!

I confirmed that I should not start the inverter without first starting the engine. When I kick on the microwave to make a cup of tea in the morning it's great to see that, after 3 minutes with 100+A coming from the engine, the Victron actually shows that I've gained available Ah, not lost them.

Hope this helps

 

[knotflying]

I am more of a pre-emptive action person then reactionary. Gauges and such are great, but they are telling you want may have happened or what is happening. I suggest that you sit down and add up all the amps that you are using while anchored out. You may be surprised at how much you may be consuming. Needless to say, if your usage is in excess of your capacity it won't matter what batteries you have. You can interpolate state of charge by voltage. Not as accurate as a gauge , but certainly enough to tell you what is going on. Batteries and religion have a lot of discussion and everyone holds fast on their preference of battery type. I have always been a proponent of flooded Walmart batteries; guaranteed for a year and usually available no matter where you are. Simply because most batteries, regardless of type, are destroyed due to owner error. We all will make that mistake at sometime and I would prefer to do it on an inexpensive battery. I replace mine every three years regardless of condition. I am never concerned about battery condition as long as I use amperage wisely. I know when I wake up in the morning I will have 12.45V on the meter. If it starts to reduce. I know something is going on and it is time to check it out.

 

[Hamster]

Many folks on this forum always advocate for Victron products. If you have a Victron solar controller, that makes sense to keep in the same product line. When I looked for a battery monitor, my local battery shop and online reviews led me to Balmar. The Balmar also does State of Health that monitors your battery condition over time. It also has a Bluetooth option.

Here is a review of the Balmar. https://marinehowto.com/balmar-sg200-se ... y-monitor/

I love having the gauge and think it is an essential electronic on a boat or RV. Both monitors will work for you.

 

[Craigmconrad]

I do recommend Victron. I use a the battery sense's on each bank and have the 5ooa Shunt and 100/30 Solar Controller. All works very well. I do run an Ipad with Navionics displayed and the Victron Connect overlaid. It works well when I decide to run the AC underway to monitor the SOC.

 

[philbyrd]

My R-25 with the lithium option came with the Balmar battery monitor system. Gauge next to the water tank gauge at sink. I also installed the bluetooth module, which the factory does not include. It has settings for battery chemistry for the house bank, so it is not just for lithium banks. It is $60 bucks and plugs into the back of the module under the sink. Not a lot of space but does click in. As I understand, it also could have gone in the main module in the lazerette, but more protected under sink. App works well on iPhone and there is plenty of support online. It will open on an iPad but is not designed for it, you get a portrait view only. The system has channels 2 and 3 that you can connect to the starter and thruster batteries to see their voltage as well, which the factory does not do either. The module is in the center lazzerette, and the leads to run to the other batteries are on the unit. I plan to do that hook up next weekend. For monitoring the “State of Health” I encourage you to Google reviews on the Balmar system. The Cruisers forum has a lot of very technical info. there are some specific install requirements to pay attention to, such as the main module being close to the battery it is wired to. It seems the system needs to have the battery go through several charge cycles for the Balmar SOF reading to be accurate, less so for new batteries however. My testing indicates that for my boat the factory promised of 8 plus hours of AC one the hook corresponds with the battery monitor “time left” when I run AC from the inverter with charged batteries. I am assuming the system also accounts for incoming energy from the DC to DC charger which is the solar panel and alternator. The time remaining is all over the place on shore power, but you can monitor the charge state, voltage and current draw. It settles down quickly when you unplug.

 

[Martin610]

Hi,

Good post philbyrd, helps me out.

I just installed the Balmar on my boat. Bit of work as I had to make some new battery cables and install a bus bar but it was worth it. You get a lot more information that you can get from just a voltmeter. In my CW28 you can't read the voltmeter very well unless you actually step down into the cave.

I have only installed the blue tooth module thus far, I have not put the gauge in yet. I was thinking it would be really convenient to have it installed next to the water gauge in the galley. Glad to hear that is how the factory does it. Now I have to figure how to run the cable. Those Deutsch connectors are cool, should make it easier to route the cable.

I'm going to see how well Balmar's algorithm for "State of Health" actually works.

-martin610