Solar panel question

[Stu Jackson]

I think what people are missing is that this is a short term solution to my problem. The solar is a long term solution to our short term sailing.

When my charger is repaired or replaced, that will be my primary mode of replenishing the batteries. The solar will augment that and help keep the batteries up when out sailing for the weekend or long holiday's.

Here is the info on the Solar Panel (x2):
Pm Watts: 20
I pm Amps : 1.18
V pm (Volts): 17
High Efficiency Mono Crystalline

The reason I asked about your "backup" charger & continued to suggest that you repair your TrueCharge charger first is because of the issue of "Is there life after death?" for seriously depleted batteries, discussed by Calder on pages 47 & 48 of the 2nd Edition of "Boatowner's Mechanical & Electrical Manual."

Getting dead batteries back to life requires:

Equalization - which only your TrueCharge can do for you

and

Charging to full is required before you equalize - which you could possibly do with your backup charger

After you've done this, if you've repaired your TrueCharge, you should check the electrolyte with a hydrometer after the batteries have rested.

You should also check the batteries after a day's use and leave a load on overnight and check them the next morning for voltage.  You could well bring the voltage back up and they may appear to be fine, but you need to find out if they'll hold a charge over a period of time with a load on them.

Wile this discussion by Calder is for wet cell batteries, the following is from the Concorde / Lifeline battery website for AGMs:  http://www.lifelinebatteries.com/manual.php


LIFELINE BATTERY OWNER'S MANUAL
Congratulations on the purchase of a new Lifeline battery! Lifeline has been the leading name in AGM (Absorbed Glass Mat) batteries since 1993. The quality and durability of the Lifeline battery series has been proven again and again in military and commercial applications worldwide.
# The AGM difference: 20% faster recharge than a conventional vented battery and gel cells.
# 100% maintenance free. No addition of water needed.
# Classified as "NONSPILLABLE"
# Tested to stringent military shock and vibration standards.
# Designed to reduce outgas under normal charging conditions.

Conditioning/Equalizing Charge: 15.6 volts for 8 hours
Conditioning/equalizing should only be done when the battery is showing symptoms of capacity loss. If conditioning/equalizing is necessary, first go through the normal charge cycle. Once the battery is as fully charged as possible, start the conditioning/equalizing charge.

IMO, the size of your solar is not "a long term solution to our short term sailing" because of the energy budget discussed above and your small panel(s), even if you keep your fridge off.  1.18 amps in full sunlight, times 5 hours per day = less than 6 AH!  Even double that just keeps up with your lgihts and stereo, or whatever you're using.

With your robust chunk of batteries, if they are re-wired properly into the largest bank you can make, you CAN actually run your fridge when using the boat away from the dock.  You plug in when you get home, so why not start enjoying the full benefits of the appliances you have on the boat when you're away from the dock?

As far as battery charging "in the morning" I recommend you read this, which will explain why you're not getting much into the house bank after a night on the hook because of battery acceptance.  Even with a high output alternator (& I don't know if you have one) not much is going back in in the morning, although that hot water sure is nice, isn't it!    See: reply #20 and the rest of this topic: http://c34.org/bbs/index.php/topic,4454.15.html  It says:

"Let's say you have a 400 ah house bank.  20% of that is 80 ah, about what we've found we use on one overnight stay with the fridge running (400 X .2 = 80).  That's enough "down" for the regulator to instruct the alternator to start pumping max amps as soon as the engine gets going.

"However, that same 20% is the HARDEST of all to put back into the house bank, due to acceptance and that "last 20% is the hardest to replace without shorepower."  You can run your bank down to 50% and most cruisers use the 50% to 80% range of their house bank to minimize engine running time for charging.  Therefore, we can get two or three nights on the hook with that daily 80 A draw down (we have 360 ah in our house bank)."

If you rearrange your wiring a very small amount and change from the way-old two equal bank philosophy to a largest house bank you can arrange, you'll be in much better shape for your electrical system.

Good luck on your TrueCharge repair or replacement.

[Lance Jones]

I am NOT an electrician. So, all of the numbers have no meaning. In fact they're confusing me. As I've said I have 4 AGMs organised into 2 banks. From what others have said with AGMs, you don't equalize them nor is there an electrolite issue. I MAY BE wrong, probably am.

That being said, all I wanted to do with my short term battery charger was to charge enough to start the motor and get my on board high out put charger working. It charged it well enough over night to start this morning. As my in-laws are in town and are afraid to be on the water, all we did ALL DAY was motor. Now, batteries are charged and I have an appointment with my electrician on Monday to fix my REAL charger.

I am very interested in doing the big bank theory; but, that will be for a later date.

Cheers!

[Ron Hill]

Lance : I have 3 group 31 AGM batteries and as you said they(AGMs) never need to be equalized and do not self discharge.  I have about 315 AH capacity (not including a starting battery) that seldom drain down by more than 40 AHs before I recharge. 
They are maintenance free and have a longer warrentee period that any other type battery.  They are going on their 6th year and show little wear (accepting a charge). 
Don't know if you did any damage letting them get to a low discharge, but a load drawdown check after recharged, will tell you their health.  Good luck .   

[Stu Jackson]

I am NOT an electrician. ....to charge enough to start the motor and get my on board high out put charger working. It charged it well enough over night to start this morning. Now, batteries are charged and I have an appointment with my electrician on Monday to fix my REAL charger.  I am very interested in doing the big bank theory; but, that will be for a later date.

Understood.  Glad to hear it worked.  That's great news.  When the electrician comes on Monday, you may want to share these battery bank ideas with him.  He may be able to get you "the big bank theory" while he's there simply by moving and adding a couple of wires to get at least three of your four batteries in one bigger bank now, and then you can ponder your future choices.  At least this important enhancement can be done rather easily and with little time or effort on his part.  You'll have a nicer boating and refrigerator season, too.    I wasn't an electrician when we bought our boat, either. 

Enjoy your 3rd Annual Memorial Day Brunch on May 25th.

All the best, Stu

[waterdog]

Stu,

I have 390 Watts of solar panels that I am going to install.   Will be able to run my stereo all day long and still display an anchor light at night?   

Thanks,

Steve

[Ron Hill]

STEVE : I BELIEVE THAT STU (AS KNOWLEDGEABLE AS HE IS) needs some more information. 
Will the sun shine and how many amps does your stereo draw.  Those two are starter guestions.   

[Lance Jones]

For those that are waiting with baited breath..... My batteries held their charge well overnight Saturday after all day motoring. She started right up Sunday morning, we motored out into the wind <5 minutes running, raised the sails, turned on the fridge, sailed all day. When it was time to return, it was also time for the big test..... she started right up!  So, I think the batteries are fine.

Now, today I'll have the electrician fix the charger and look at converting to a three battery house bank. Thanks for all y'alls help. BTW, #2 bank had a higher charge than #1. Could that be due to the solar panel hooked into #2?

[c34no1471]

I might have some useful input on this issue.  I installed two 54-watt Kyocera solar panels a year ago, and tied them into a smart two-battery charge controller.  I have a Link 20 (now Xantrex) battery monitor.  The panels provide a MAXIMUM of just over 6 amps, in full direct (overhead) sunlight.  That maximum is rarely achieved.  I actually get between 20 and 30 amp-hours of charge of the the panel on a typical summer day here on the Chesapeake Bay. I have two group 4D AGMs, totalling about 400 amp hours of (theoretical) capacity.  I never run them down below 65 per cent of that number.

The 20-watt panel, in this same setting, would provide less than one-fifth of that total, or four amp-hours or so (that's just an estimate).

I like the panels, they fit well on the deck just forward of the traveler, and my batteries are always fully charged when I go to the boat after a few days away.  I almost never plug in to shore power.  I can anchor out an extra night or two without running the engine to charge the battery.  Solar panels are a great idea, but we need to be realistic about their capacity to charge batteries.

George Alberts
Breezing Up, Hull no. 1471

[Lance Jones]

Thanks George.
These are just to "top off" the charge and give a Little boost for our weekend cruising. When we move to the shore and live aboard, I'll have a different solar arrangement at that time. I got the 2 x 20w panels for free along with their regulator. Will not look a gift horse in the mouth. Well, at least directly.

[Stu Jackson]

Thanks for the feedback, Lance, and glad it worked for ya!  Keep us posted, I've switched from holding my breath to crossing my toes - great exercise for the broken leg!