Solar not keeping batteries up

[jacwjames]

Started having this problem last year.  In the past my 325 solar would keep the batteries up even if unplugged and the salesman switch was in the ON position.  Then last year if the salesman switch was left on, eventually the batteries would drain.  I checked connections and batteries, which appeared to be good.  I started checking loads and did notice a high drain on the house side with salesman switch on, even with everything turned off.  So I shut the salesman switch off which solved the problem for the time being.  I checked the battery levels often and they were holding a charge and it appeared the solar was able to keep up, this was even through winter when there were less day light hours.

About 3 weeks ago I decided to dewinterize the coach, I put out the bedroom slide out to have access to the washer and dryer.  I then filled the water tank with a bleach solution to sanitize, running the water pump to fill the lines.  I then closed the slide and shut the salesman switch off.  Over the next couple weeks I checked the batteries every couple days and noticed they were not charging and slowly draining, even with the longer daylight hours.  It appeared from the solar display that it was putting out ~+14 volts to the batteries but the amps seem to be low.  I finally relented about 4 days ago and switched the power on the coach to fully charge the batteries. 

Yesterday, the batteries were at 100%.  I drained all the water from the system and refilled with fresh water and then ran the water pump to flush each leg of the piping.  While I was doing this I did notice that when I was running the pump the solar amps did increase, I guess compensating for the load I was applying to the batteries.  When I was done the batteries were still at 95% based on the inverter panel and the solar display was showing +14 volts charging with slight higher amps. 

Haven't checked on the batteries today.

What would be causing the solar charging system to work and then not work keeping the batteries up even with the salesman switch off.   Any suggestions on what to look for.  I understand there is a better load monitor that I could install to monitor my usage, any suggestions on make/model.  I thought I had saved a file on this but can't find it. 

 

 

[Guest Cruzbill]

Ahh batteries! Which has more hits on these forums; batteries or tires??

 

Has it been unusually cloudy over several days or weeks? Clouds/fog (weather) is the #1 reason for lower solar production. 325w of solar is equal to a 15a trickle charger that only works say, 5 hrs/day; that is, on a good sunny day! Check your batteries with a hydrometer. Check each cell in each battery, maybe one cell is dragging down your battery bank. If you can, keep your coach plugged in and let your inverter/charger keep the batteries up. Solar is great, (I have 7kw solar on the S&B) but its only a trickle charger and can't do miracles, especially in winter and or cloudy wx.   

Lithium batteries are the solution, but just too costly for me at this point in time.  

[jacwjames]

I checked all  the battery cells last year with a hydrometer when I first realized I had a problem.   The system seemed to be working fine all through the winter, even with limited daylight hours. 

I may take the time to check each solar panel, I did this several years ago and they were working as design.  Last time I waited for a full sun, high noon, and covered 2 of the 3 panels and recorded the voltage and amperage, then added the amps up to see what the max charge capacity was.  At the time, from memory, it was +15 amps, which seemed about right for 325 watt solar. 

Not ruling out this as an issue though as the batteries are 7 years old but when I installed a Samsung last year and while testing it I decided to see how long the batteries would work.  It was very hot out and the fridge was empty so essentially worse case scenario.  The batteries were still +50% of charge after more then 8 hours so from that I figured the batteries weren't a problem.    I am considering adding more solar and new batteries, not sure if I can afford lithium though.  Maybe there will be some price reductions with current economics. 

What confuses me is why it work fine for several months and then quit working.    I'll continue to monitor and see if I can identify the problem.  For the time being not planning on any trips but would like to have the coach ready if/when I decide to do some traveling.

Thanks for the reply

 

 

 

[Guest Cruzbill]

Even a small parasitic load (say 3a) will equal or exceed your solar charging output. I bought a cheap clamp on DC ammeter in order to chase down my battery problems. Found the inverter, which is connected directly to the batteries, is the biggest culprit. Even when switched off. 

 

https://www.walmart.com/ip/NCV-Ohmmeter-Tester-Diode-UNI-T-Digital-True-Mini-Test-Backlight-Voltage-Ammeter-Multimeter-Bag-Voltmeter-LCD-UT210E-Resistance-Storage-Clamp-RMS-Cap/939968573?wmlspartner=wlpa&selectedSellerId=101001360&adid=22222222227290500234&wl0=&wl1=g&wl2=c&wl3=350605456242&wl4=aud-430887228898:pla-747067993666&wl5=1014098&wl6=&wl7=&wl8=&wl9=pla&wl10=128133340&wl11=online&wl12=939968573&veh=sem&gclid=CjwKCAjwpqv0BRABEiwA-TySwSn5H1aW3548pIEu_A1YTAN3jIf7h8xLaBkApjzkp7VfWHr74dADwxoCDD8QAvD_BwE&wmlspartner=8*X6Fwho90A

 

[jacwjames]

Yes, I have a clamp on amp meter, its an older analog model but still works.  I started checking amp draws last year.   I did find a high parasitic draw with the salesman switch on, never tried to really pin point, just turned the salesman switch off and at the time solved my problem.  I also saw that the inverter does have a draw even when it is off.  But before my solar was able to keep up even with the inverter off. 

I checked the batteries charge just a little while ago, it was 100% and today it is overcast.  So it's been ~4 days where its stayed at 100% after I had it plugged in and got the batteries to 100%. 

[Guest Cruzbill]

7 yr old batteries, you must take good care of them. We finally moved into the one spot at the storage yard that has a shore power receptacle. Keeping the MH plugged in solved my charging problems; I just installed a residential refer (and sine wave inverter) but have yet to check the battery drain. 4x GC2, so about 220 AH total (at 50% discharge). I'll check the cells next with my hydrometer.  

[jacwjames]

I installed them 2013 but was still working, last trip we took was in Oct 2015, then started clearing property and been build my wife a house for the last 3 years, besides doing a 7 month consulting gig in 2017.   I try to take care of them but they haven't really been heavily used.  But I know I will have to replace sooner then later.

Still would like to figure out what is going on with the charging/electrical system.   Hate to put new batteries in with some sort of sporadic parasitic drain.