GraniteStaters Posted November 2, 2020 Share Posted November 2, 2020 Paula and I were camping in NY state campgrounds this fall and we had several sites that didn't have power and ran into some cloudy rainy weather in our next to last campsite. We were running our refrigerator on LP and did have the furnace on, but other than that we only had a few USB devices plugged in. It had been cloudy and rainy all day. I woke up during the night and discovered we were running below 11 volts. I installed a VictronConnect Battery Smart Shunt in early August and have visibility into how many Ah draw we were using. It was a bit over 1Ah per hour except when the furnace was running. I rushed out to plug our RAM which has a very powerful generator installed as opposed to running the generator in the middle of the night. We turned off the furnace immediately and limped until the early morning when I ran our propane generator to recharge the batteries to sufficient charge. We also charged for several more hours later that evening after experiencing another cloudy overcast day. We didn't get to full charge, but we thought we were okay. We didn't run the furnace at all that night and experienced the low voltage again in the early AM. I checked the batteries and 2 AGMs were fine at 6.4 volts, but 2 AGMs were running 4.48 volts as I recollect. I opened a ticket with Oliver to discuss. Eventually was advised to discuss the issue with Trojan. We are still working through this issue, but I wanted to get your thoughts about what I have since discovered. First the batteries are 6 volt with each of the 2 wired in series to get the combined requirement for 12 volts. Each of the 12 volt strings are wired to be parallel too for more Ah depth. My assumption was that I was seeing the issue on one set of the 6 volt batteries wired in series, but now that I have examined the pictures and the documentation I see that the first battery in each parallel series is experiencing the unusual draw down after just a small drain and only a few hours of use, but only on cloudy days when there is insufficient solar gain to recharge. We had the problem 4 nights before we gave up and headed home. We have reproduced the unusual discharge at home after just 4 hours on a cloudy day. When we have sufficient sun or use shore power at home, the batteries always come back to fully charged status per VictronConnect. We haven't seen full charge indication on the Zamp but once since onset of the problem although we have been plugged in for several days in a row now. What I am wondering is why I would see the first battery on the negative side of each series be low voltage? Wouldn't the draw down occur from both strings equally? If the batteries are truly okay, why wouldn't we see one of the parallel strings still provide sufficient voltage, but for a shorter duration? I am sure there is a lot I don't know about this setup, but figured that some of you more experienced owners might have some valuable insight. I am continuing to work with Oliver/Trojan to resolve this issue and expect to have at least the two suspicious batteries tested by Trojan very soon. David Caswell and Paula Saltmarsh Hull 509 "The Swallow" Link to comment Share on other sites More sharing options...
GraniteStaters Posted November 12, 2020 Author Share Posted November 12, 2020 Good news on this issue. The Trojan Black AGM 6V batteries were found to be defective after testing by the regional distributor in our area. I had an hour trip to a service location that they service, but it was worth it to identify the issue. They only pick up or deliver the batteries once a week to this service location, but it means that we were without 2 of the 4 batteries for just two weeks. I will be reinstalling next week and doing some testing of the new batteries. Jason Essary, Oliver Service, facilitated this successful outcome to everyone's benefit. 5 David Caswell and Paula Saltmarsh Hull 509 "The Swallow" Link to comment Share on other sites More sharing options...
Patriot Posted November 12, 2020 Share Posted November 12, 2020 GraniteStaters - Good news and thank you for sharing the final positive outcome. In our experience Service Manager Jason Essary is top shelf and will do everything he can to help resolve issues. He knows how to get things done! Happy Camping! 1 2020 OLEII - Hull #634 aka- “XPLOR” 2021 F350 6.7 liter Diesel Lariat Ultimate Tremor North Carolina 🇺🇸 Link to comment Share on other sites More sharing options...
John E Davies Posted November 12, 2020 Share Posted November 12, 2020 (edited) FYI, open cell (no load) voltage testing of AGM batteries really tells nothing, the readings can be very close to each other, but the batteries can still be bad. The ONLY way to check the health of an AGM is to load test it. Any battery shop like Batteries Plus Bulbs .... Batteries Plus Bulbs Store Locator ....... can do it in their parking lot at no cost, in a couple of minutes. The batteries need to be charged as much as possible, and then disconnected from each other for at least six hours so they can reach a true resting state of charge. Also FYI, if you install a Victron Connect smart bus, program it, and assume that it is giving you correct numbers about the percent of charge, you are traveling uncharted waters if you first don’t verify that all are perfectly healthy. I had three bad batteries and one almost bad one, and my monitor was saying I had 100% capacity, but any serious load would simply kill the system, the inverter would start cycling on and off. Only lithiums which have onboard diagnostics give you true information. My recommendation to AGM owners: charge, remove and have load tested all your batteries at the start of each camping season. Regular “wet” lead acid battery cells can be individually checked using a hydrometer, which gives useful info, but they still should be load tested. John Davies Spokane WA Edited November 12, 2020 by John E Davies 5 SOLD 07/23 "Mouse": 2017 Legacy Elite II Two Beds, Hull Number 218, See my HOW TO threads: Tow Vehicle: 2013 Land Cruiser 200, 32” LT tires, airbags, Safari snorkel, Maggiolina Grand Tour 360 Carbon RTT. Link to comment Share on other sites More sharing options...
GraniteStaters Posted November 12, 2020 Author Share Posted November 12, 2020 As it turns out, we have cloudy day today and I will testing the two remaining AGMs to see that they work well under extended use. I have the VictronConnect and Smart shunt to gather stats and monitor easily over the next few days. I will only run the refrigerator on LP, the furnace and turn a few lights after it gets dark and recheck after a few hours a couple or three times tonight and when I wake up tomorrow. 1 David Caswell and Paula Saltmarsh Hull 509 "The Swallow" Link to comment Share on other sites More sharing options...
GraniteStaters Posted November 13, 2020 Author Share Posted November 13, 2020 Well, testing overnight went very well. We used about 25Ah of power from the last full charge. It stayed about 12.25 volts until the batteries recharged from the Solar panels in spite of the overcast conditions. Using the Aux port on the Victron Smart Shunt, I able to monitor both batteries concurrently. This is very handy. When I receive my replacements and install them as two pairs pairs of batteries, I will reconfigure the Aux to be a midpoint voltage monitor to insure that I have visibility on how each set of 6 volt batteries are behaving. 1 David Caswell and Paula Saltmarsh Hull 509 "The Swallow" Link to comment Share on other sites More sharing options...
GraniteStaters Posted November 16, 2020 Author Share Posted November 16, 2020 I am adding a great document from Victron's library that explains the ins and outs of batteries, wiring considerations and monitoring. Very helpful. https://www.victronenergy.com/upload/documents/Wiring-Unlimited-EN.pdf 1 David Caswell and Paula Saltmarsh Hull 509 "The Swallow" Link to comment Share on other sites More sharing options...
GraniteStaters Posted November 24, 2020 Author Share Posted November 24, 2020 (edited) One final post on this issue. We received two brand new Trojan AGM 6 volt batteries last week and I finished the reinstall last Friday. After doing a pretty good checkout and with some cooler dismal days in the forecast for NH, we set up a recreation of our failing scenario. We set the furnace to 50 degrees and the refrigerator to LP. We ran our main cabin lights last night for 5 hours to simulate our normal behavior. We had a very rainy evening Sunday night and Monday morning until late in the day. We have been running for over 41 hours with almost no solar gain and have drawn 58Ah of draw since the last report of fully charged as reported by the VictronConnect software. Our voltage on both 12v pairs was 12.4x this morning. Jason Essary of Oliver service was extremely helpful with Trojan on our behalf. We are both very grateful. David Edited November 24, 2020 by GraniteStaters Clarity 1 4 David Caswell and Paula Saltmarsh Hull 509 "The Swallow" Link to comment Share on other sites More sharing options...
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