Agm eastpenn (2) with 14w solar

[rgleason]

Have two group 25 eastpenn agm with balmar alt and are regulator plus a 14w solar panel. Sometimes I see voltages above recommended voltages for charging, like 14.6v and 14.7v . Is this likely to damage the batteries? Also these Batts purchased 2009 june, used primarily for refrigeration, and seem to charge up to 12.5v only. Last year charged to 12.8v. Last year was first year with 14w solar panel. Kept Batts charged w 3 step charger all winter.

It appears we've lost capacity, any idea why? Did not notice max state of charge last fall.

[rgleason]

Actually group 24, also the 14.6 to 14.7v are with 14w solar only.

Sent from my SCH-I545 using Cruisers Sailing Forum mobile app

[colemj]

14W? Are you missing a zero on the end of that? That would only produce 1 amp of current, so it could only drive your batteries to that voltage if it is unregulated and your batteries are fully charged. Even then, my bet is that it wouldn't happen.

You say the batteries will only charge to 12.5V, but are somehow being charged at 14.7V?

Mark

[rgleason]

Mark,
You are exactly correct, solar PV is 14w, 1 amp output. With engine off and Batts batts charged up to 12.5v with balmar AR5 regulator supposedly set to Agl AGM setting (mechanic may have changed something), then eventually see voltages of 14.6 to 14.7v in the link 10 e meter due to the pv solar trickle charge.

Mark I totally get your point, why don't the Batts charge up to 12.8v when at rest? Possibly loss of capacity?

Engine - alt now charging properly at 14.3 volts bu bulk at 1750 rpm. Batts accepting at 8th to 7ah.

[colemj]

OK, I misunderstood how you are using the term "charge" to mean the voltage a charging source is driving them to, not a resting voltage after all sources have been removed.

If your panel does not have a charge controller on it, I guess it is possible that if you have a fully charged battery, zero draw on it, and full sun that the battery could reach those voltages.

If this is the case, then you need a charge controller for your solar, or need to keep a small load running off the batteries (0.5A would probably be fine).

Mark

[Zil]

You can not hurt your agm battery by charging with a 14 watt solar panel. Your problem is you do not have enough charging capacity to charge your battery bank. You can hurt your battery by not charging enough.

[rgleason]

Well after summer use it appears our westmarine AGM batteries charge up to 12.45 volts. Period. We've lost capacity and this is sooner than expected! These Batts are getting worse, not better. So do we need new ones yet with our refrigeration or should we go o e more season.

Interested I. Good alternatives the last longer.

Sent from my SCH-I545 using Cruisers Sailing Forum mobile app

[Maine Sail]

Originally Posted by rgleason

Actually group 24, also the 14.6 to 14.7v are with 14w solar only.

Sent from my SCH-I545 using Cruisers Sailing Forum mobile app

And this 14W of solar has a controller..? If not then there is your answer. The 14W of solar is simply over charging the batteries...

I can push two 6V 220Ah Lifelines to over 15V with an 12W panel and this is enough to FRY these expensive batteries. The general guidance found on-line, or even in the West Marine Advisor, about controller-less solar is pure and utter rubbish....

[Maine Sail]

Originally Posted by Zil

You can not hurt your agm battery by charging with a 14 watt solar panel. Your problem is you do not have enough charging capacity to charge your battery bank. You can hurt your battery by not charging enough.

Sorry but this is simply INCORRECT.......!

You CAN DESTROY your batteries with no controller and a 14W panel. I have seen this numerous times and on banks much larger than two 24's.......

Why? Because the general guidance on this is utter rubbish with no practical basis in fact....

This is a bank of 400Ah's of L16's and this it what it takes to maintain 14.4V if left charging....


400Ah bank 0.1A to maintain 14.4V........ Where do you suppose the voltage would be with 10X that current or 1.0 amp?



Do I Need a Solar Charge Controller? (LINK)



The above link should be self explanatory....

[rgleason]

Yes, I agree. The Batts only reached 12.45v this spring and I thought that that voltage would increase as I used and charged them this summer. They did not improve.

I purchased the 14w solar panel last spring so possibly the damage was done last year.

What controller is best - cjarcteristics/ type/ manufacturer and model? I would like to be able to add panels.

Also is it possible for my balmar ACR5 to overcharge on long runs when set on Agm? Voltage drops down to 13.3 I think. I have no bat temp or alt temp sensors as my mechanic says that is overkill for my 14th install.

Sent from my SCH-I545 using Cruisers Sailing Forum mobile app

[rgleason]

When I purchased the panel both the manufacturer and west marine said I would not need a controller.

Sent from my SCH-I545 using Cruisers Sailing Forum mobile app

[Ex-Calif]

How far down do the batteries discharge on average? How many cycles to 50% in the last 5 years?

[Maine Sail]

Originally Posted by rgleason

When I purchased the panel both the manufacturer and west marine said I would not need a controller.

Sent from my SCH-I545 using Cruisers Sailing Forum mobile app

They were wrong, if you left them connected for longer periods between uses.

Read the link I posted above and watch the videos. The small Morningstar PWM controllers are quite good..

[rgleason]

West marine Penn Agm group 24. 7ah × 2 = 144 ah total when new 3 to four years ago. Current max charge voltage is 12.
45 vdc. Danfoss bd 50 refrigerator has been low on charge last two years (trouble free since 2001) and drew down batts about two or 3 times (50-60 amps) when did not shut circuit off. That was last year. This year recharged with 134a after full evacuated and it is running better. Last year added pv 14 watts to top off battery at end of a trip. Left it charging on the mooring.

This winter charged batts left in dry basement had to recharge them midwinter, very low.

How should I load test to find out capacity?


Sent from my SCH-I545 using Cruisers Sailing Forum mobile app

[rgleason]

Will look into Morningstar regulator. Is there a good Charger / inverter / PVregulator on the market that would be suitable?

If I need to replace batteries which ones? I like the fact that AGMs charge fast during motoring in and out of harbor.

Sent from my SCH-I545 using Cruisers Sailing Forum mobile app