Forum Discussion

Vintage465's avatar
Nov 22, 2019

Thinking a Battery Monitor.............

I've completed my upgrade to my Solar System (There is a thread on "Do it yourself Modifications) Thinking(after the fact of course)that I should have considered a Battery Monitor in the upgrade, or at least preparations for such an install.

I know very little about battery monitors except that most experienced boon dockers with solar recommend them. I don't see any reason to try and take a low rent route to get this done and end up with an iffy unit that works her and there or not at all.

I hear the Morning Star unit is kind of the standard. I also hear some pretty good things about Victron.

So:
1. I assume a shunt needs to be installed some where on the negative near the battery bank. I've seen the pic's of one and it looks pretty straight forward to install. Is the shunt the sending info to a "brain" then bluetoothing to the little round read out on a Victron? How would I size the shunt? We only use 12v. No inverters. The only high draw item we have is the furnace. How close or far from the batteries is acceptable to install the shunt. Should it be very easily accessible? Meaning, is there a reason to view it regularly?

2. I have Samlex PWM 30a controller, will a Victron or Morning Star work with that controller? I looked in some installation info and reading material and that info doesn't seem be very forthwith as of course they are hoping one uses their charge controller.

3. In order to have Bluetooth connectability for monitoring does there have to be a "base unit hardwired somewhere that the iPhone can snag the signal?
Is that what I'd be doing by installing a shunt with the wiring going to the hard wired battery monitor?

4. Maybe there is a good link to send me to that has "battery monitors 101"?

5. How accurate are the lower priced units using a "hall" sensor? I mean.....those are $40.00 and the Victron is $200.00, seems like a lot of $$$$ left on the table if they do the same thing. Do they provide the same data with the same level of accuracy?

Thanks!

23 Replies

  • Ed_Gee wrote:
    1) the shunt is the sensor that measures all current into and out of the battery. It should be installed in the negative battery cable going to chassis ground. It does not need to be readily accessible. The best quality battery monitors do NOT use bluetooth....the sensor connects to the display monitor by wire cable.
    2) a battery monitor will work with any charge controller.
    3)no comment....I prefer hard wired display - no bluetooth.
    5) shunt type sensors are extremely accurate .....Not sure how accurate Hall sensor types are in comparison.


    Bluetooth is bad? That's a bold assertion. My Victron with Bluetooth works great.
  • 1) the shunt is the sensor that measures all current into and out of the battery. It should be installed in the negative battery cable going to chassis ground. It does not need to be readily accessible. The best quality battery monitors do NOT use bluetooth....the sensor connects to the display monitor by wire cable.
    2) a battery monitor will work with any charge controller.
    3)no comment....I prefer hard wired display - no bluetooth.
    5) shunt type sensors are extremely accurate .....Not sure how accurate Hall sensor types are in comparison.
  • Vintage465 wrote:
    1 Is the shunt the sending info to a "brain" then bluetoothing to the little round read out on a Victron? How would I size the shunt? We only use 12v. No inverters. The only high draw item we have is the furnace. How close or far from the batteries is acceptable to install the shunt. Should it be very easily accessible? Meaning, is there a reason to view it regularly?
    No, that's a hard wire. The bluetooth is to your phone. I'm sure the 500a version would be fine for almost any installation. Mine's close, but I have no reason to think it needs to be. No, but I choose to view mine on the smartphone almost every day to make sure the solar or shore charger is working.

About Technical Issues

Having RV issues? Connect with others who have been in your shoes.24,316 PostsLatest Activity: Sep 12, 2025