Battery Charges Higher Volts with Solar...

[TravisH]

Hi,

Brand new Lifeline AGM batteries and brand new Progressive Dynamic converter. Converter set at AGM and basic charging setting. Keeps batteries 12.7v

Boondocking and plugged in Zamp solar panel suitcase and batteries up to 13 volts and climbing....

Why is this so? Should I change the setting on the Progressive Dynamic "wizard" or does keeping them at 12.4v good enough?

Thanks!

Trav

[Rolind]

I assume your zamp suitcase has its own charge controller. Start by checking the settings on your zamp controller and make sure the match the recommendations for your batteries.

[Wazbro]

12.7 volts is about full charge (depending on temp), it is not enough to fully charge the batteries. 12.4 volts is 75-85% charged so that would give you a little more then half your usable capacity.
With that said how are you measuring voltage? Are you sure it is accurate? No the monitor on the wall is not always accurate, hopefully it is within .2 volts, it also varies depending on loads.
Charging should/needs to get over 13.5 volts, not start there with really low batteries.

[cc retired]

I have a basecamp 20x with the AGM batteries and factory Zamp solar. 2022 build. Boondock and Harvest Host a good bit. System has worked well until recently. Usually, the solar keeps the batteries around 13 volts. The Victron controller readings depend on the sun, up to 150w. Last boondock the battery dropped to 11.5 and the controller was registering 7w in full sun. Ended up shutting down the refrigerator, the voltage stayed at 11.5 until I drove to the next camp and it was back to 12.5. Nothing obvious was amiss on the roof, the fuses are good. Any ideas where to look?
Thanks to all.
CC

[10Smiles]

Could be the angle of the solar panels to the sun. Not sure where you are, but around here (NW Washington) the sun is pretty low all day and the orientation of the trailer to the sun makes a huge difference due to the curved roof (which, therefore, slants the solar panels).

[gypsydad]

I went thru this for 6 years with my currant AS...and another 14 years with previous 3 AS's! The lead acid batteries do not hold a charge of 12.7V very long, in my experience. Easily can go down below 12V after couple days especially if using the furnace. My biggest reason for moving to Lithium this past summer: the Li batteries provide solid 12.7V for 5-6 days of use without loss of power and will maintain that down to around 20% capacity; your lead acid will drop fast, at/below 60%; not unusual for mine to read <11.9V after couple days. Fire up the generator or use your solar if you have it, but Li is the way to go. Thats why I made the switch finally....procrastination...but wife is very happy now. We recently boondocked for 5 days and still had 56% capacity reading on my LiTime Bluetooth BMS.

[cc retired]

With full sun overhead and batteries clearly needing juice, is it normal for the solar to only put out 7w? Never had this issue before, did same trip last year with same setup. I'm still trying to figure out what to expect with this setup. I'm thinking solar connection is bad or whatever sensor is used to detect low battery is having an issue. Not sure where and how to check (or could hit up the dealer - 4 hour trip).
Thought on Lithium is when the AGM quits, will convert and the LI will be that much better and maybe cheaper too. The rig is already wired for LI with a toggle to reset system to LI.

[Al and Missy]

7w in full sun sounds like a solar problem to me. Bad or obscured panel or poor connector contact on controller input or output, or bad controller. AGMs repeatedly discharged below 12 volts are probably toast, but solar should still be putting out a lot of power to 11.5 volt batteries.