Size of Battery Charger

[zboss]

Originally Posted by sailinglegend

May I direct you to the Lifeline AGM site and suggest you download their 37 page AGM manual.

http://www.lifelinebatteries.com/manual.pdf

I really don't want to read a 37 page manual to learn how to charge my batteries.

[sailinglegend]

Originally Posted by zboss

I really don't want to read a 37 page manual to learn how to charge my batteries.

What a strange response after your original post where you talk about Lifeline AGMs, and your subsequent posts where you clearly need to read a lot more about charging your batteries. There are a lot of people here trying to help answer your questions - I sometimes wonder why we bother.

[goboatingnow]

Originally Posted by sailinglegend

Dave, you are looking at a Trojan site - they say "generally" and then offer their thoughts - based on their batteries. Trojan are good, but look deeper into their AGM range.Their "OverDrive" batteries are described by them as true Deep Cycle.

You guys out there who continually knock AGMs without knowing the facts need to get out a bit more. May I direct you to the Lifeline AGM site and suggest you download their 37 page AGM manual.

http://www.lifelinebatteries.com/manual.pdf

Remember - NOT ALL AGMs are the same. Some are designed as starter bats, some as dual purpose, some as Telecom and Solar standby bats, and others like Lifeline are designed for long life and are robust enough for repeatedly falling off 3 metres waves.

We have been permanently living aboard our 42ft Hunter Legend for the last 7 years and our AGMs are now in their 10th year.

I have a set of 6 flooded LAs, that will be 12 years this year, and are quite heavily used. So what really good batteries last longer, but AGM is a waste of money on a typical boat , spend the money on good flooded LAs.

[zboss]

Originally Posted by sailinglegend

What a strange response after your original post where you talk about Lifeline AGMs, and your subsequent posts where you clearly need to read a lot more about charging your batteries. There are a lot of people here trying to help answer your questions - I sometimes wonder why we bother.

Don't take it personally. I just don't think it should take 37 pages to learn how to charge a battery. A real benefit would be battery instructions that can sum up how to charge in 1 page.

Are Trojans available world-wide?

[goboatingnow]

Originally Posted by zboss

Don't take it personally. I just don't think it should take 37 pages to learn how to charge a battery. A real benefit would be battery instructions that can sum up how to charge in 1 page.

Are Trojans available world-wide?

more or less yes. but hard to find, there are several good makes of battery

dave

[Patacha]

Originally Posted by Cpt Pat

An excellent point! My solar array cost $1,000 and is just enough to replenish my AGM batteries. If I substituted flooded cells, I'd have to spend $1,300 to accomplish the same task.

Why is that, Pat? Please elaborate.

[Patacha]

Originally Posted by zboss

I really don't want to read a 37 page manual to learn how to charge my batteries.

In a Nutshell, Z...

- Bulk Stage: Charger provides it's max A untill battery voltage, typically 14.5-14.8V (depends on battery type). At the end of this stage, batteries are 80-80% full (SOC).

- Absorption Stage: Voltage remains constant as per the above and current drops gradually untill current is 2-5% of the max A at the Bulk charge (also limited by time; 4-8 hrs/).

- Float: voltage drops and held at 13.2-13.4V

Well, it tured out to be a Coconut shell...

[Cpt Pat]

Originally Posted by Patacha

Why is that, Pat? Please elaborate.

Because the charge efficiency of AGMs is greater than flooded batteries. That's because - digging deep into the physics of batteries - AGMs have a lower Peukert exponent. Peuket's law applies to both discharging and charging lead acid batteries.

A larger percentage of recharge energy returned to a flooded battery is converted to heat, and so, a larger solar array is needed to recharge flooded batteries of the same capacity. Given the costs of both money and space for a solar array, the savings in using AGMs is substantial for those of us who don't have or don't want to use engine-driven alternators. You also save fuel if you do run the engine to recharge AGMs, but the offset isn't as obvious.

I recommend reading this very excellent document for a detailed description of all the other variables: Battery Types: Flooded versus AGM and Gel.

[hellosailor]

I'd have to agree with zboss about not wanting to read 37 pages.

37 pages to explain the technology and concepts and options, maybe, sure.

37 pages to say "OK, this is how to charge these puppies." NO WAY IN HELL.

If you can't put the "operating instructions" in a single page bullet list that can be read and followed in under five minutes, there's something seriously wrong, and a team of dog catchers needs to be sent to the plant to round up the stray engineers and put them back in the lab.

Charge at this rate. Operate at these temperatures. Maybe even, "caution, do not drill holes in the batteries to secure them to the bulkhead." But 37 pages? That's about 36-1/2 too many for an operating guide.

[Cpt Pat]

Originally Posted by hellosailor

I'd have to agree with zboss about not wanting to read 37 pages.

37 pages to explain the technology and concepts and options, maybe, sure.

37 pages to say "OK, this is how to charge these puppies." NO WAY IN HELL.

If you can't put the "operating instructions" in a single page bullet list that can be read and followed in under five minutes, there's something seriously wrong, and a team of dog catchers needs to be sent to the plant to round up the stray engineers and put them back in the lab.

Charge at this rate. Operate at these temperatures. Maybe even, "caution, do not drill holes in the batteries to secure them to the bulkhead." But 37 pages? That's about 36-1/2 too many for an operating guide.

I see it as a time versus money thing. Time reading and researching versus money spent on more stuff than I needed to buy because I over-specified/burnt out/broke the stuff I bought. I have more time than money, but I appreciate that those of a more affluent class do a lot to support our economy.

Sometimes I do wish I was rich enough to afford cheap batteries.

[pbiJim]

Originally Posted by zboss

I just don't think it should take 37 pages to learn how to charge a battery. A real benefit would be battery instructions that can sum up how to charge in 1 page.

Page #19

http://www.lifelinebatteries.com/manual.pdf


The general spec's on that battery look pretty good to me. I'm impressed that it can take a max bulk charge rate of 250% of the ah rating. http://www.lifelinebatteries.com/marineflyer.php?id=30

[Stu Jackson]

37 pages isn't much if he wants to learn. If he doesn't and wants charging for dummies, then he might, just might make a catastrophic mistake and burn up his batteries.

Maybe he'd like to learn about how batteries work:

Ample Power Company Home Page

But then he'd have to download the Ample Power Primer and read it. It's more than one page.

Ooops, sorry.

Dave gave the simple answer quite a number of times. Unless you can guarantee charging back to 100% (however you choose to do it) then AGMs could fail on you without warning. I'd give a link, but would it be read?

2 hours vs 3 hours to fully recharge a bank based on the size of a 40A vs 60A charger? Nah. If you read most battery literature, you will need all night to FULLY recharge a bank, even if you had a zillion amp charger. It's called battery acceptance.

Good luck, keep learnin'...

[pbiJim]

Originally Posted by Stu Jackson

Unless you can guarantee charging back to 100% (however you choose to do it) then AGMs could fail on you without warning. I'd give a link, but would it be read?

I would like to read it.
Please post the link.

Thanks,
Jim

[Stu Jackson]

Sure, and one's on acceptance, too

AGM Battery Issues (from Maine Sail)
AGM Batteries - Making The Choice - SailboatOwners.com

AGM Battery Issues and the Blue Seas Dual Circuit Switch (from Maine Sail) "DARN AGM Batteries"
Darn AGM Batteries - SailboatOwners.com

Battery Acceptance by Stu Battery Acceptance

Battery Acceptance (a very good Maine Sail presentation and further discussions) Battery Acceptance Observations - SailboatOwners.com

Happy reading.

[ranger58sb]

Originally Posted by Stu Jackson

2 hours vs 3 hours to fully recharge a bank based on the size of a 40A vs 60A charger? Nah. If you read most battery literature, you will need all night to FULLY recharge a bank, even if you had a zillion amp charger. It's called battery acceptance.

Good luck, keep learnin'...

Wasn't me complaining about the 37 pages; I like to read stuff like that.

I did mention the extra hour for 40 vs 60 amp charger. That was just a guess, and I think I said 3 vs 4... but in any case, that's just based on what my gauges say after a 4 hour charge now (from about 30% depletion) with our current 40-amp charger.. Full.

I understand the acceptance part; I'm suspecting my normal (i.e., quick check) gauge in the saloon (analog, not the multi-meter) isn't sufficiently accurate to for me to distinguish the continuously-shrinking? remaining charging activity.

-Chris