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frankpaige
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# Posted: 20 Jun 2022 18:18
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I should have written down the system components before I left the cabin. Hopefully someone might have some ideas? It is a small system. 1- 100 watt panel, controller (p30L?), inverter, (2) AGM batteries. All new within 3 years. I have 3 LED lights, usually recharge the IPad, toothbrush, this year hearing aid battery pack (yes, old and too many bomb blasts), occasional phone charge. That is really all the usage.
This springtime I have had issues. It started with maybe the battery pack and iPad. Now it seems the batteries will not hold a charge. I can charge things during the day when sun is out.
Do I instantly go to the batteries as suspect? They are sealed AGM. No signs of freezing, bulging?
You know they are heavy suckers. Do I do a state of charge test there. Disconnect. And then check next trip?
During the day, there seems to be no issues with charging.
Or? Do I bring back the batteries to town and have someone check their condition?
Thanks all
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ICC
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# Posted: 20 Jun 2022 21:00
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I assume you have a multimeter or voltmeter.
1. After the charge controller indicates the batteries are full, what is the immediate voltage?
2. Then if you disconnect the charge controller and all loads and let the batteries sit for a few hours what is the voltage?
3. Let the batteries sit overnight with no use at all and recheck the voltage in the morning?
4. What happens to the voltage if the batteries sit for a week, no use, no charging?
I would expect reading #2 to be lower than reading #1 but still in the 12.9 to 13.0-volt range (if those are 12 volt batteries.)
Reading #3 and #4 should be about the same as reading #2 if the batteries are good.
That is how I would start the assessment.
How have the batteries been stored over the winter? What type of batteries?... 12 volt RV? 6 volt? ???
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ICC
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# Posted: 20 Jun 2022 21:04 - Edited by: ICC
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Quoting: frankpaige this year hearing aid battery pack (yes, old...
I love my rechargeable hearing aids. Hearing aids made a huge improvement to my enjoyment of life 6 years ago. I recommend them highly for those with diminished hearing. The higher-tech ones I have had for a year or so, with full Bluetooth syncing for telephone use and listening to music, etc. are the cat's ass.
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frankpaige
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# Posted: 20 Jun 2022 21:08
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ICC,
Thanks. Looks like great info. No multimeter on site. Going back this weekend. So I will give your instructions a go.
Stored over winter? Whenever I leave, I turn the inverter off, nothing plugged in. The batteries are inside the cabin. Thermometer says the lowest was -10F.
This does seem to be a new occurrence. I visit in the winter. And did not experience this issue, even with shorter daylight hours. Glad your suggestions include checking after overnight, instead of days later.
I will return with more information.
Thanks
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gcrank1
Member
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# Posted: 20 Jun 2022 21:52 - Edited by: gcrank1
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Dollars to donuts at least one of those batteries is poor to bad. And if the 2 are hooked up parallel the poor one will draw down the good one.
But, that said, disconnect all the connections, clean them and hook back up. Over time it is not unusual to have resistance build up; you need super good con's.
Flooded Lead Acid bats (agm's are just a variation on the theme) want to be kept totally fully charged. And if used they want to be recharged asap. If they dont get that they sulfate, which kills them.
ICC's suggestions are solid. If you can determine if both, or just one are still good you may get some life yet from them. But to do the voltage test they need to be Fully Charged, preferably on a grid charger at the proper 'C' rate recommended by the manufacturer.
Keep in mind that a battery can read good voltage and not have much for available Amp Hours left in it, with fla's it diminishes over time and use/abuse, that is why we have to change our car batteries too.
The other thing about FLA (inc agm's) is you need to not draw them down regularly more than 25-30%, and only occassionally to 50% in an emergency (Then re-charged asap). If those 2 bats were 100Ah (200Ah total) they diminished by 10% in the 1st year to 180Ah, of which only 45ish Ah was regularly useable, 90Ah only occasionally. Going 'deep' too often kills the bats too.
If you are down to 1 good'ish battery left, and it was a 100Ah, the same percentages apply. But your needs are quite modest, one good one may do the job 'for a while' yet.
Actually, with only 1 x 100W panel, even though you have a 30?A scc it Will Not put out 30A, No Where Near. A typical 100W panel will put out about 5-6A averaged maybe 4 hours a day in good sun. That is only 20-24A back into the bat(s). That is a 'C' rate far lower than those bats need to recharge properly. This is why Im thinking it is a battery issue.
Fwiw, 'my' rule of thumb with FLA bats is a min 100W panel per 100Ah of battery IF you have optimized array orientation and good sun much of the time. Otherwise its 2x 100W panels/100Ah bat.
If both bats are poor to bad your best bang for the buck (because agm's are expensive) is a min. 100Ah 'marine deep cycle' (Not marine 'starting') battery.
If you had more array much better would be two 'golf car' GC2 6v bats wired in series for a 12v bank (providing some 200ish Ah). But you dont have more array and possibly dont want to?
Beyond this simple system of yours is more $ for for complications, and by it more available power. More array, a better scc (real mppt) and LFP battery(s).
If you are happy with what your system provides, when working well, I think the 'marine dc' bat is your smart money battery replacement.
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frankpaige
Member
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# Posted: 20 Jun 2022 23:21
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Gcrank1, Thanks. Not that I want to think about purchasing new Batteries. But, thought it might be needed. DRAT!
ICC, I love the Bluetooth part, I really do. But, I love these because..... There is a background feature on them that allows the sound of a running stream. Hell, what better thing to listen to during naps. GOD love the VA. 🙈
There will be an update. Thanks all.
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Brettny
Member
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# Posted: 21 Jun 2022 07:24
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Do some simple diagnostics before condemning anything. You need at bare minimum a volt meter and a sunny day.
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frankpaige
Member
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# Posted: 2 Jul 2022 10:21
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Update! Do not know if I should laugh or cry?
I disconnected the batteries 36 hours ago. Evening time in the Rockies. This morning, they sit at 12.6 and 12.7 respectively. I guess, I expected one of them to be drastically different.
NOW? The plan is to take them back up next trip. Reinstall. Make sure connections are all clean and TIGHT. Then try this again.
The day before I disconnected it was sunny all day. I charged hearing aid pack in the am. iPad charged twice, 8:30pm used one led lamp and at 10:30 I got the alarm.
Is there anything I am missing?
Hope everyone has a safe and enjoyable holiday.
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paulz
Member
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# Posted: 2 Jul 2022 11:08
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Why not put a load on them now, a 12v light or something, for a load test? If you do each one separate it will give you an idea of their remaining capacity.
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frankpaige
Member
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# Posted: 2 Jul 2022 12:07
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WELL! Heck.
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paulz
Member
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# Posted: 2 Jul 2022 12:21
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That's a starter load test I believe. I've had batteries that wouldn't start a car but worked for lighter loads. I would charge them and put a load similar to cabin usage and see how long they go.
But for long term, probably new batt time.
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frankpaige
Member
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# Posted: 2 Jul 2022 14:43
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I might as well purchase new. But? I can go back to Amazon and purchase two more. OR?
I can get some recommendations here and maybe get better? I am not going to cry poor mouth. But please keep from being like Uncle Sam, spending my money!
Really, total of three lights. One used from sunset to maybe 11:00pm. iPad. I can recharge hearing aid and toothbrush during the day. I turn my phone off when I arrive. Use Jenny for microwave and coffee pot. Bar b Que used for cooked meals. Below is what I purchased.
Thanks everyone.
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gcrank1
Member
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# Posted: 2 Jul 2022 20:25 - Edited by: gcrank1
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AGMs are kinda pricey, imo. How about the Walmart 'marine deep cycle/leisure' battery (just one), about 100Ah 'rated' (but more like an 80Ah) for about $100?
You should get 25-30 Ah's daily out of it if you have decent sun the next day.
It looks like you usage is pretty light, my guess is less than 25Ah's?, so you would have some buffer room.
And, imo, your 'array' is too small to be charging 2 bats anyway, and lead acid LIKES to be kept fully charged asap after a discharge.
Buy one, fully charge it before you take it there, hook up with clean connections and my bet is you are back to happy livin.
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