Simplest battery monitor and shunt? Advice for non-expert

If you can part with $200 Victron makes a nice unit with Bluetooth, no monitor to wire up.

I also like simple so I bought the Aili battery monitor. It is only $44. There are a couple options to buy a longer wire so measure before you buy.

Probably the simplest option is the Victron Smart Shunt for ~$130.. The whole unit resides in the battery box with no holes to drill or wires to run. The output is viewable on any phone/tablet/computer. Victron also makes a version with a hardware display if that is important to you.


There are cheaper no-name options, but they have several drawbacks - they need to have the display installed and wired up, they are less accurate and most importantly, they only provide a snapshot of what is going on right now without any history. The Victron unit provides the current state of charge, but also statistics about the performance of your battery which are very useful for determining how your systems is working.

Hi profdant139,

I use a monitor that doesn't require a shunt.

It is similar to this unit:

https://www.amazon.ca/bayite-Digital-Current-Voltage-Transformer/dp/B01DDQM6Z4?th=1

Lots of great ideas in a very short time -- thanks! Keep the suggestions coming -- I can see that I have more homework to do. (I bet I'm not the only one who finds "RV homework" to be more fun than "home homework.")

Basic, inexpensive monitor no shunt,This One nothing fancy but tells me what I need.

I have one for the Chassis and one for the house batteries.

profdant139 wrote:


In your opinion, which is the most basic and inexpensive monitor? Are shunts sold separately from the monitors? What gauge cable does the shunt/monitor require?

I use this Voltminder and a battery state of charge chart. You can set an alarm on it if wanted. I bought mine direct from Voltminder, but Amazon sells them too, just you get free freight if you buy direct. They charge freight on Amazon. It is the same seller.

http://www.voltminder.com/

I use this chart off the Trojan web site, scroll down to the voltage chart. https://www.trojanbattery.com/tech-support/battery-maintenance/

Take note, the battery needs to be at rest (not charging and no practical power draws) for 6 to 8 hours to not have a surface charge that can be misleading (false high voltage). It talks about this just above the chart.

It has a 12 volt cigarette charge plug if you have a socket in the camper or your can hard wire it in. Ideal is to tie in close to the battery inside the camper if possible to avoid a long run voltage drop.

While this does not count coulombs like the Victron,(a very good feature) knowing good voltage readings and understanding what they mean, works for us while boondocking. It simple and it is close enough on SOC. Everyone has different needs when it comes to battery power draw measurement.

I do not have the need for an inverter (yet anyway) and I can manage our 12 volt power draws to minimum. If I end up getting an inverter or solar some day, then yes I would go the Victron route.

Hope this helps,

John

This monitor is the one I have. It is an awesome little unit.

I bought a Victron smart shunt and I monitor my batteries daily..I can tell you this,too the tenth my other voltage meters, as cheap as the cigarette lighter plugins and the voltage meter on my battery boxes,are pretty close to the Victron readings,but there only to the tenth and not one hundreths...Now that I know that,I feel confident in there readings..

Jayco

Boon Docker wrote:
This monitor is the one I have. It is an awesome little unit.

I had one of these a couple years ago, and it was ok for some basic information, but I had a hard time setting up some of the parameters. I ended up giving it away after I had my solar system installed. But for $30, not much to lose.
JK