Solar panel negative to battery negative

[Hayden]

Quick question. Can I directly attach my solar panel negative to my battery negative bypassing the charge controler? Note both battery terminals will still be connected to the charge controler

[Wy_White_Wolf]

Depends on the charge controller but most of them will require the panel to be hooked to it.

WWW

[Sunking]

Quick question. Can I directly attach my solar panel negative to my battery negative bypassing the charge controler? Note both battery terminals will still be connected to the charge controler

No.

[ILFE]

Depends on the charge controller but most of them will require the panel to be hooked to it.

I agree. I have a MorningStar controller, where the negative terminal of the PV input, battery and load, are all common. On other controllers I have, they are independent of each other.

The question that begs to be answered is, why would you want to bypass the controller?

[Hayden]

My controler has separate negatives for all 3. So there is no harm in just trying it? Reason I ask is I am trying to wire in an ammeter which will read the solar panel current and flick a swith and will read battery current but while doing so I failed to account for the negative. Its only a small set up for a portable radio with a few power points and a floodlight

[inetdog]

My controler has separate negatives for all 3. So there is no harm in just trying it? Reason I ask is I am trying to wire in an ammeter which will read the solar panel current and flick a swith and will read battery current but while doing so I failed to account for the negative. Its only a small set up for a portable radio with a few power points and a floodlight

You can get all of the readings you want with an ammeter or shunts in the + leads. Any particular reason that you want to put it on the - side instead?

[Hayden]

Just because thats where the instructions for it said to wire it but it doesn't matter I would still have the same problem on the positive side. When I flick the switch it changes sources heading to the ammeter so I have the battery running through the ammeter then to the negative of the charge controler but when I flick the switch so the panel is running through the ammeter the negative is already connected to the battery negative on the controller. I was just wondering if I could avoid having to add another switch. Sorry im fairly new to all of this.

[inetdog]

Just because thats where the instructions for it said to wire it but it doesn't matter I would still have the same problem on the positive side. When I flick the switch it changes sources heading to the ammeter so I have the battery running through the ammeter then to the negative of the charge controler but when I flick the switch so the panel is running through the ammeter the negative is already connected to the battery negative on the controller. I was just wondering if I could avoid having to add another switch. Sorry im fairly new to all of this.

I am not really clear on just how you are switching your ammeter. If you are taking an actual analog ammeter with full current flow through the meter, you could just connect one end to the common point and the other end to each of the individual wire destinations. That involves a pretty complex switching process so that you do not open any of the circuits along the way. (Switches interrupting high DC current tend not to last very long.)
Or you could simply put a shunt in each of the three paths, with a common point, and switch the voltmeter that reads the shunt voltage to each of the shunt ends in turn.
Very simple, but at the cost of three shunts instead of one.

[SunEagle]

Just because thats where the instructions for it said to wire it but it doesn't matter I would still have the same problem on the positive side. When I flick the switch it changes sources heading to the ammeter so I have the battery running through the ammeter then to the negative of the charge controler but when I flick the switch so the panel is running through the ammeter the negative is already connected to the battery negative on the controller. I was just wondering if I could avoid having to add another switch. Sorry im fairly new to all of this.

Best and IMO the safest way to measure the panel or battery current at the same time is to have 2 ammeters. They can be either in-line type or using a shut and volt meter. Using the same instrument to measure two things and relying on switches may cause a short which is not safe.

You also have to remember the current flows usually in one direction so it is real easy to get your ammeter hooked up backwards giving you an incorrect reading.

It will cost more but 2 is better than 1 in this case.