What batteries are you using and where are you buying them?

[sailinglegend]

Originally Posted by conachair

But we can help others by not posting misleading comments.

Which is why it would be helpful to others to be more precise in your posts. I did say use the search function.

What is misleading in my post. It's a fact that so many people just don't want to accept! I usually post great diatribes that people don't read properly. You didn't read MaineSail's post properly earlier about time to get to 100%. His test were not Real World tests which would go to FLOAT. He stayed in Absorption which is not good for the batteries. Search the internet for more MaineSail postings on fully charged by midday.

Fully charged is something that all batteries should achieve at least every three weeks or they permanently sulfate and loose capacity. 98% is not good enough!

[conachair]

Originally Posted by sailinglegend

.

What is misleading in my post.

"you can NEVER get to 100% every day with Solar alone." is just wrong, you can with a decent setup but not if you go into float early.
It's wrong and misleading, but you don't seem to be able to accept that.

[a64pilot]

Originally Posted by conachair

Which is why it would be helpful to others to be more precise in posting, "you can't get fully charged with solar" is a bit misleading, what would be more helpful would be to go into why this might be the case on some boats and what can be done to get up to full charge.

OK, I have 1KW of Solar into an Outback 80. I have not left yet so this is all theory. I have 660AH Lifeline bank.
My plan is to leave the Solar in absorb voltage, there is no such thing as bulk, that is only absorb, but current limited, but leave in absorb and watch charge current, if I can get to only 3.3 amps charge at absorption voltage I am at 100%.
Gut feeling is I won't quite get there, I will run out of sunlight first, remember as batteries age, charge time gets longer, so it might work with a new bank, but not one with a couple of years on it.
Back up plan if it won't get me to 100% is to run the generator twice weekly early in the morning to slam some high amp bulk charging in, make water, wash clothes, make ice, whatever. Then let Solar get me to 100%. So my AGM bank should get to an honest 100% twice weekly.
Also will likely buy a slip once a month to equalize the bank and to rent a car or at least do all the bulk replenishing.

But all theory so far, but at least it's a plan? I'll let you know in 6 months or a year on how well it works.

The other wild card is of course the useable hours of sunlight vary by time of year, so you may have enough Solar to get to 100% in Jun.,but maybe not in December in the Northern hemisphere

[Blackie Swart]

I really battle with electronics but I've put in 3 x 200amp Lead Crystal batteries and feed them with 3 x 345Wp Sunpower solar panels. This is also monitored with a Victron 80/2000 invertor with VE.Net Blue panel monitor. It's 17H15 here at the moment and cloudy and I'm still getting 6amp input from the panels. My 220v invertor runs all day. I get to 100% just about every day, depending on what I've done. Sometimes I power up the 220v hot water geyser for hot water. I have Fisher Panda 8000NE but hardly use it. I'm never on dock, so rely on my system.

Works well so far.

[Maine Sail]

Originally Posted by sailinglegend

He stayed in Absorption which is not good for the batteries.

Staying in absorption until the batteries are full is the ideal charge profile. Once full you then drop to float. This is the best case scenario and exactly how it is done in the lab. Unfortunately with voltage controlled charging this is not possible so the goal is to drop to float at the highest SOC you can attain using CC/CV charge equipment. Unfortunately this equipment usually falls short, & grossly so in far too many applications..

Originally Posted by Sailinglegend

Fully charged is something that all batteries should achieve at least every three weeks or they permanently sulfate and loose capacity. 98% is not good enough!

Every three weeks is too long if you want optimal life.. Sandia National Labs Photovoltaic Division has studied this extensively and max suggested PSOC duration is recommended at no more than 1 week. The more often you get to 100% SOC the longer the battery will last..

[sailinglegend]

Originally Posted by conachair

"you can NEVER get to 100% every day with Solar alone." is just wrong, you can with a decent setup but not if you go into float early....

Maybe if I had said 99.9% of readers "can NEVER get to 100% every day with Solar alone." would have been more accurate.

Forget about solar - to get a battery bank fully charged with a shore power charger and take current for the boat loads will take 12-20 hours. Most Solar arrays can't provide that much constant power, so I still stand by what I have said.

[Zil]

sorry to not read through. someone may have already posted this. Duracell label are from Deka, made by East Penn. I don't believe energizer are made by East Penn. I have 6 GC2 and found the best price at Batteries plus Bulbs. They are found throughout NJ, and I expect NY.

[conachair]

Originally Posted by Maine Sail

Every three weeks is too long if you want optimal life.. Sandia National Labs Photovoltaic Division has studied this extensively and max suggested PSOC duration is recommended at no more than 1 week. The more often you get to 100% SOC the longer the battery will last..

Was that the fabled “PV Hybrid Battery Tests on L-16 Batteries” ? which seems to be password protected again.

Some interesting recommendations though..

The study has four conclusions:
1. The finish voltage (sometimes called the absorption
voltage) for a flooded lead-acid battery operating at
12 VDC nominal should be about 15.3 volts (2.55 per
cell) rather than the customary 14.4 volts.
2. Finish charge time should be at least 3 hours and
often longer.
3. The maximum interval between finish charges should
be about five days.
4. Not all brands of L-16s are the same (though the
report names no names).
The general conclusions of the Sandia report are
consistent with the number one problem experienced in
off-grid PV systems—undercharged batteries. Richard
Perez has for many years advocated higher finish
voltages for PV-engine generator systems. As he says,
“I like to run them hot.”

15.3v does seem a bit excessive unless you don't mind watering often.


http://www.homepower.com/view/?file=HP89_pg120_IPP

http://www.zetatalk3.com/docs/Batter...dures_1998.pdf

[a64pilot]

Originally Posted by sailinglegend

Maybe if I had said 99.9% of readers "can NEVER get to 100% every day with Solar alone." would have been more accurate.

Forget about solar - to get a battery bank fully charged with a shore power charger and take current for the boat loads will take 12-20 hours. Most Solar arrays can't provide that much constant power, so I still stand by what I have said.

I don't think it should take that long, it takes mine about 6 maybe 7 hours from close to 50%, but I have not timed it, it's rare that I discharge that deep. I have 185 amps of shore power charging though for a 660 AH AGM bank

[conachair]

Originally Posted by sailinglegend

Maybe if I had said 99.9% of readers "can NEVER get to 100% every day with Solar alone." would have been more accurate.

Forget about solar - to get a battery bank fully charged with a shore power charger and take current for the boat loads will take 12-20 hours. Most Solar arrays can't provide that much constant power, so I still stand by what I have said.

The mainesail data has already shown less than 5 hours at absorption will get to full charge, as the charge acceptance tails off an adequate solar array should easily cope with that.
So your saying that only 1 boat in 1000 has a properly designed solar system and knows to keep the voltage at absorption.
Sounds like 100% unreseached guesswork.

[sailinglegend]

Originally Posted by conachair

The mainesail data has already shown less than 5 hours at absorption will get to full charge.....

MainSail data says:

Here we are at 100% SOC at the .2C charge rate and it took 5:42 minutes.

And on the same page he also says:

IMPORTANT: Please understand that you will never likely charge this fast with a typical smart charger.

His is not a "real world test" because his test doesn't drop to FLOAT and battery manufacturers insist on Smart Chargers that drop to FLOAT and don't stay in ABSORPTION. If a charger stays at 14.4v when the battery is 100% full it will cause excessive gassing - and he is testing an AGM which will charge faster at 0.2C - and many people won't be charging at 0.2C.

You chose the facts that suit your argument. If someone else wants to continue this discussion sensibly I am prepared to listen.

Originally Posted by a64pilot

I don't think it should take that long, it takes mine about 6 maybe 7 hours from close to 50%...

But how to you measure 100% fully charged?

When fully charged you should see 14.4v or higher and delivering 0.1% of C. You will never see this condition because the charger drops down to a FLOAT voltage.

[sailorboy1]

just get the batteries that you like and have talked yourself into and make them serve you instead of you serving them and move on to enjoying your boat

[conachair]

Originally Posted by sailinglegend

MainSail data says:

Here we are at 100% SOC at the .2C charge rate and it took 5:42 minutes.

And on the same page he also says:

IMPORTANT: Please understand that you will never likely charge this fast with a typical smart charger.

His is not a "real world test" because his test doesn't drop to FLOAT and battery manufacturers insist on Smart Chargers that drop to FLOAT and don't stay in ABSORPTION. If a charger stays at 14.4v when the battery is 100% full it will cause excessive gassing - and he is testing an AGM which will charge faster at 0.2C - and many people won't be charging at 0.2C.

You chose the facts that suit your argument. If someone else wants to continue this discussion sensibly I am prepared to listen.

Don't drop to float!! How many times does this have to be repeated. Where is that data that 6 hours at absorption is going to kill a battery, you've already been shown that absorption should be kept until the batteries are charged. 14.4v doesn't for a few hours doesn't cause excessive gassing, my trojans are set to 14. 8v and use little the water.
If you have any actual facts to back up any of what you say then please link, so far it's just been blanket statements with not a single piece of backup.

[sailinglegend]

Originally Posted by sailorboy1

just get the batteries that you like and have talked yourself into and make them serve you instead of you serving them and move on to enjoying your boat

I tend to agree with you, but there are a lot of viewers of this thread and many probably want to get the best out of what maybe very expensive batteries.

I've repeatedly said use the search function as all the arguments have been repeated here by me and the likes of MaineSail on other forums.

Batteries and charging are a very complex and not fully understood part of cruising. If you're a full time liveaboard like me for 10 years then they become a lot more important. My current AGMs have lasted 12 years, so I must be doing something right! Posting just a few lines can't fully explain or convince some disbelievers.

[conachair]

Originally Posted by sailinglegend

The battery must reach 14.4v (@77F) and it is fully charged when the charge current going into the battery is 0.5% of the bank capacity (C)..

Originally Posted by sailinglegend

But how to you measure 100% fully charged?

When fully charged you should see 14.4v or higher and delivering 0.1% of C. You will never see this condition because the charger drops down to a FLOAT voltage.

Disagreeing with yourself there by a factor of 5 - is that a convenient moving the goalposts typo?