OK so 50 amps full scale, .1 volt input. .002 ohms. 2 feet of #10 wire is your shunt. You can even coil it up and make it nice and small.
Put it on the ground side of your battery. Then the telemetry measures from true ground to the other side of the shunt. I have done wire shunts many times. From: George Skorup Sent: Wednesday, August 30, 2017 11:29 AM To: [email protected] Subject: Re: [AFMUG] Cost effective battery charging and monitoring device Yeah, about that. I wouldn't use those on 12VDC systems. Too much current. I've burned up a couple of the 10A shunts on Traco BCMUs that were running around 200W load on battery. 200/13 = 15 amps. Ungood. One site at about 225W, first time it went to battery, the shunt went kaput after 10-15 minutes and the site went down. I'm hoping Forrest comes up with some Hall effect stuff or even plain 20+ amp shunts that can be used on the SiteMonitor's existing 100mv input. Hall effect is nice because you don't have to be "in" the circuit. But I'll take what I can get. On 8/30/2017 10:26 AM, Adam Moffett wrote: Yeah, up to 10 amp. ------ Original Message ------ From: "Chuck McCown" <[email protected]> To: [email protected] Sent: 8/30/2017 11:18:36 AM Subject: Re: [AFMUG] Cost effective battery charging and monitoring device I think Forrest has them on his site with the site monitors. From: Sam Lambie Sent: Wednesday, August 30, 2017 9:15 AM To: [email protected] Subject: Re: [AFMUG] Cost effective battery charging and monitoring device Parallel. Site Monitor! Now where can I get a shunt? On Wed, Aug 30, 2017 at 9:09 AM, Chuck McCown <[email protected]> wrote: 4 batts in series or parallel? Shunt + sitemonitor would be a better way to go and you don’t have to write code. From: Sam Lambie Sent: Wednesday, August 30, 2017 9:06 AM To: [email protected] Subject: [AFMUG] Cost effective battery charging and monitoring device Hey all, I am getting away from using APC at a couple of our sites and right now I have installed a Tripp-Lite APS750 connected to 4 Deep cycle marine batteries for a total of 404 aH system. I'd like to be able to monitor the discharge rate of the batteries when power is out remotely. What have you guys been doing to that effect? I'm thinking a Pi and a shunt and some quick scripting classes on Python to put it all together... -- -- Sam Lambie Taosnet Wireless Tech. 575-758-7598 Office www.Taosnet.com -- -- Sam Lambie Taosnet Wireless Tech. 575-758-7598 Office www.Taosnet.com
