PDA

View Full Version : Permanently connected solar panel on vehicle.



Homestar
10th August 2014, 11:35 AM
For convenience, I've mounted my 140 watt solar panel to the roof of the 101. Now, I know that sometimes that's not going to be great as I could be parked under a tree while camping, but I can deal with that. My question is around it staying connected to the batteries all the time.

I run a 630CCA cranking battery and a Full river 100AH deep cycle. My current setup is a manual switch to disconnect the starter while camping, but sitting in the driveway, I've left them connected.

The regulator shows that everything is fully charged, and the red 'charge' LED just flicks on briefly every 3 or 4 seconds - sort of like a float charger does when everything is full charged.

The batteries are showing 13.57 volts during the day, and drop down at dark to 12.75 volts.

So, am I going to do any damage long term leaving everything connected like this? I've never had to worry about it before I did this. Both batteries are brand spanking new, so I don't want to overcharge them or reduce their life.

Also, I'm looking for a battery monitoring system that can show volts on both batteries as well as charge and discharge current. Any recommendations on something? Don't mind spending a few dollars, but I don't really want to spend a fortune on a top end unit. I don't want one that stays lit all night - it would drive me nuts, so an LCD display is what I'm looking for.

Cheers - Gav.

drivesafe
10th August 2014, 01:00 PM
Hi Gav and I sell the worlds leading battery chargers and I don’t sell any solar gear.

BUT, nothing looks after batteries better than a standard solar setup, not even my brand of battery chargers.

If you watch your solar reg voltage in the morning, it will probably go to over 14v for a short time then settle back to the 13.57v you normally see.

13.57v is a good float/maintenance voltage level.

When your batteries settle back to 12.75v at night, they are showing they are in a fully charged state.

Just leave it alone, it’s working perfectly.

Here’s a chart to monitor your batteries while camping.

https://www.aulro.com/afvb/images/imported/2016/06/640.jpg

Homestar
11th August 2014, 09:13 PM
Bump.

Any ideas or suggestions on the second part of my question regarding a battery monitoring device that shows amps in and out as well as volts? Only need something that is good for 15 amps tops.

Blknight.aus
11th August 2014, 09:26 PM
Don't worry about it.

Just run off best guess and plaster the SOC chart drive safe posted up and probe them with a meter. Every now and then.

After a while you'll learn what your systems doing and will be able.to guess the state of the batteries to within a couple of percent.

drivesafe
11th August 2014, 09:48 PM
Hi again Gav and as Dave posted, plus from observations and feedback from many customers over the years, I have found that most people who spend up on things like battery monitoring systems because they think they need them.

But after the first few trips away, the novelty wares off and the BMS is then a waste of money.

But each to his own.

spudboy
11th August 2014, 10:31 PM
If you are going to monitor the amps in/out you'll need a shunt in the circuit. Just seems like another thing that can fail (and I say that not knowing if there are any moving/breakable/etc parts in a shunt!).

If you've got a good regulator, you can leave it all permanently attached. Mine sits at 13.4v or 13.5v all day (when sun is shining anyway) and then drops down to 12.7v at night.