Back in the day I installed a Link 10 battery monitor so I could know exactly what was going into and out of the battery bank while I was boondocking. Fast forward and I now have a new trailer and I'm in the process of moving mods from the old to the new. My new trailer will, eventually, have a solar system installed. Can the modern charge controllers today double as a battery monitor of sorts? If, at the least, the charge controller registered every amp hour sent to the battery from all sources, that would meet my biggest need. Do the new controllers do this? Thanks

Hi Ryan,Yes, some controllers have sophisticated monitoring systems, including the ability to be tweaked using a computer.Here is a simple flow chart.Budget-->Energy Audit-->Battery bank size-->number of watts-->PWM or MPPT. What ever type of controller is chosen, make sure it has adjustable set points and a temperature probe that is on the battery.One rule of thumb is between 60 and 150 watts of panels per 100 amp-hours of storage. The smaller the battery bank the higher the wattage needed (per 100 amp-hours). Here is a link to the rather special spreadsheet which includes an energy audit, that N8GS has created to help size solar battery charging systems!Solar Spread Sheet N8GSFor a nice explanation of solar, try this link:Golden rules of solar

Mostly, no. The solar monitor just has a shunt for the solar and not for the rest of the rig. It is nice to know the amps the solar is doing at any time, but the solar AH info is fairly useless.The Trimetric has a shunt that sees everything including the solar. the solar monitor shunt( if any) is upstream from the Trimetric.There is a new controller monitor (ISTR called the Kid?) which has the shunt arranged to subtract solar from "all" and you get the whole story--forget exact details.So take the Link with you to the new rig.Some solar controllers have a built in ammeter and display so you don't need a shunt etc. Tthat gives you what you want to know about how the solar is doing without having to pay for a solar monitor at all. The $35 Solar30 PWM has that and so does the $102 Eco-Worthy MPPT for instance. Works great.

RKW wrote:If, at the least, the charge controller registered every amp hour sent to the battery from all sources, that would meet my biggest need. Do the new controllers do this? ThanksNo, only solar production is measured by the controller.Although you may find less need to monitor the battery with a well sized solar charging system. (220+ watts)

RKW wrote:Can the modern charge controllers today double as a battery monitor of sorts? If, at the least, the charge controller registered every amp hour sent to the battery from all sources, that would meet my biggest need. Do the new controllers do this? Hi RKW, Bogart Engineering's TriMetric TM-2030 can do this when used in conjunction with their SC-2030 charge controller.Here's a Quick Reference Guide that shows how the two interact.Cheers, -Mark

some solar controllers will tell you the battery voltage ?but it won't take the place of a more sophisticated Power monitor

Can a solar charge controller act as a battery monitor?

12 Replies

BFL13
Explorer II
Nov 01, 2014
Mostly, no. The solar monitor just has a shunt for the solar and not for the rest of the rig. It is nice to know the amps the solar is doing at any time, but the solar AH info is fairly useless.

The Trimetric has a shunt that sees everything including the solar. the solar monitor shunt( if any) is upstream from the Trimetric.

There is a new controller monitor (ISTR called the Kid?) which has the shunt arranged to subtract solar from "all" and you get the whole story--forget exact details.

So take the Link with you to the new rig.

Some solar controllers have a built in ammeter and display so you don't need a shunt etc. Tthat gives you what you want to know about how the solar is doing without having to pay for a solar monitor at all. The $35 Solar30 PWM has that and so does the $102 Eco-Worthy MPPT for instance. Works great.
pianotuna
Nomad III
Nov 01, 2014
Hi Ryan,

Yes, some controllers have sophisticated monitoring systems, including the ability to be tweaked using a computer.

Here is a simple flow chart.

Budget-->Energy Audit-->Battery bank size-->number of watts-->PWM or MPPT. What ever type of controller is chosen, make sure it has adjustable set points and a temperature probe that is on the battery.

One rule of thumb is between 60 and 150 watts of panels per 100 amp-hours of storage. The smaller the battery bank the higher the wattage needed (per 100 amp-hours). Here is a link to the rather special spreadsheet which includes an energy audit, that N8GS has created to help size solar battery charging systems!

Solar Spread Sheet N8GS

For a nice explanation of solar, try this link:

Golden rules of solar

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Can a solar charge controller act as a battery monitor?

12 Replies

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