diy solar

diy solar

Victron Smart Shunt and Battery Monitors

Thanks for the reply. I will have to read this over a few times so I can understand this better. I think most would agree that changing the settings should get me some accuracy.

I have also included some pictures that a couple of you have requested.

I can not thanks those that are taking their time and helping the novice out!!!Shunt.jpgBattery Model.jpgBatteries.jpg
 
The shunt looks to be wired in correctly. THank you for providing the photos.

mikefitz already put together a great post with some guidance on programming. I would say the biggest problem in your settings is probably the SmartShunt tail current. The default 4% is 8amps on your 200ah setup. This is quite a bit and with the charging source being a small solar system it is very easy for current to fall below this level due to clouds or etc or even at the end of the day.

The shunt does not know that the charging source is inconsistent. It is expecting that the charging will only slow down once the batteries are full. At the end of the day as the sun goes down the charge current slowly goes down (due to less PV watts) and this appears to the SmartShunt the same as a battery reaching a full charge.

Reducing the tail current to 1% will hopefully ensure that the SmartShunt does not do false pre-mature synchronizations.

I think it would be a good idea to do a full and complete charge cycle with a battery charger and then do a new manual synch with the new settings in SmartShunt and lets see now it does.
 
Relieved that the shunt is in correctly although I was careful when I did it and double checked a week or so ago. I have done dumber things in the past.

Kind of hurts when you call my solar small----just kidding of course.

I think your suggestion is spot on including the reset. No problem running my generator at the end of the day. I have mentioned it in the past but I am normally in float around two in the afternoon. Get back to square one and see what happens.
 
And your original concern was that it was inaccurate. If you have a clamp on multimeter you can clamp the cable and see if you're reading matches the reading that the shunt is giving. Really what the shunt is measuring is amps and then after that it's just simple mathematics to use time and amps to calculate amp hours.
 
And your original concern was that it was inaccurate. If you have a clamp on multimeter you can clamp the cable and see if you're reading matches the reading that the shunt is giving. Really what the shunt is measuring is amps and then after that it's just simple mathematics to use time and amps to calculate amp hours.
I do have one but I found that it needs new batteries. Will run to town in the next day or so and get new batteries. I need three and of course I had one.

Thanks again for all your help and will update after changing those recommended settings.
 
I just wanted to give an update. So a couple of days ago I made the suggested changes. The batteries went to float mode around 2 in the afternoon as normal. When the sun went down I then started my generator and ran it for a couple hours giving the onboard charger time to make sure I was at 100%. I then synchronized my system. I have now had two discharge cycles and one charge cycle. The discharge cycles are MUCH improved. Before solar kicked in today I was showing 78% SOC and 47.5 amp hours used which is way closer. In my mind it SOC should have been slightly lower. Suggestions on any more setting changes would be much appreciated. The one charge cycle That I did was back to 100% SOC and when the sun went down it showed 0.6 amp hours used. It went to 100% when it showed around 1.7 amp hours used. Thanks again for any and all help.
 
Lead acid or agm is about 94% efficiency, if theres a setting to change the charge efficiency to 94% then you’ll get a better result…
 
Lead acid or agm is about 94% efficiency, if theres a setting to change the charge efficiency to 94% then you’ll get a better result…
There is that setting. Currently at 90 percent if I remember correctly.
 
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