Batteries

[ebb]

We have no formal thread on batteries,
altho we touch on the subject in a number of threads.
One such is called Battery Charger.

www.morganscloud.com
On the web site menu punch 'electrical' and scroll down to BatteryTest 1 & 2.
google > AGM Battery Test Part 1
and AGM Battery Test Part 2
has a long discussion on lead/acid batteries (which includes Wet, Gel and AGM. These guys are cruisers with big boats and big battery banks. Their comments on the nature of each generation and type of battery is an excellent read with some relevance to our boats. It's a different class of conversation and things can be learned from their exchanges.

Pricey AGMs have been on my wish list for a long time.
I made models and created a slide for three batteries either 24, 27, or 31.
Have them planned for the lowest possible position under the bridge deck.
The hype I have subscribed to is that there is no hydrogen out gassing when charging.
And the simplicity of no maintenance. And longer life than wet.
NOT as simple as that since AGMs require high tech gizmos to TRY to keep them happy.
We get to read how not easy it is to keep AGMs on a boat.

I have very persuacively been convinced that 6V golfcart batteries could be the way to go.
4 6volt GCs will fit in the same space as the 3 standard sized AGMs.
I have seen these 6V in AGM form at twice the price, But cost wise regular wet GCs might be the way to go.
EXCEPT for the outgassing problem, sulfating and sulfuric acid in the accomadation.
A good percent of the MorgansCloud guys bought the hype but now don't like AGMs - some having installed and cruised with them for years - which is surprising to me anyway -
but you might want to read WHY?

I'm still confused. But what remains is
HOW DO WE SAFELY LIVE WITH WET CELLS IN OUR ARIEL/COMMANDER CABINS?


Any input on this?
How do you deal with ventilation? ....anything foolproof?

[Commander 147]

Ebb

First let me responde to your last statement. I've come to believe there is nothing "foolproof". I've seen fools go to extreame lengths to overcome obstacles to do their deeds. But for the rest of us (although I sometimes wonder about myself) there are some options that are more "reasonable" than others.

When it comes to electrical issues I've come to think highly about the opinion of Nigel Calder. I have his book "Boatowners Mechanical and Electrical Manual" and I refer to it often. But what made me start looking into the batteries that I plan to use for Destiny's electrical inboard drive was this article.

http://sailmagazine.com/boatworks/en...to_the_future/

The TPPL batteries from Odyssey are the baatteries I plan to use.

Read the article over and let me know what you think.

[ebb]

Reasonable options is what these pages are all about!
Including the wit and humor from certain Commandereers.

Next generation batteries are extremely attractive and expensive.
And I believe that Nigel Calder article is almost 5 years old.
So maybe there's been some acid gone under the plates by now.
Stamped out paper-thin (less than 1/64 inch and 99 44/100 percent pure virgin lead) pages does sound like an advertising gimmick, but maybe there's been enough time to get the bugs out of this FOURTH type of lead/acid battery.
By necessity thin plates would have to be supported by something inside like glass mat,
So I assume all the TPPL have to be AGM. Don't think that Gels are seriously considered anymore.

This tricky new product has to be linked with sophisticated electronics.
And the way I read it, AGM batteries, as far as cruisers are concerned, don't work well off grid.
They're not foolproof even with expensive controllers and cruising conditions.

So, the new bat will bring us another set of problems, large and small, that have to be worked with and worked out? - or is the TPPL the maintenance-free answer? Will they vent, for instance? Can they take any neglect?

Are we still waiting to see?
Are there 3 happy sailors out there that have 3 years of cruising with these babies?
At some point I'll compare costs of GCs with TPPLs.

The battery mounting system will still need a leakproof tray for the battery bank.
And a waterproof lid to insure against shorting and dollops of water coming through the companionway!

And I agree with you that NIGEL CALDER is the most trustworthy guru we have on marine matters. He is faultless so far as I can read into his M&EM tome on marine esoterica. I have his cruising volume as well. Will read anything that comes up Calder publishes in the media. We are lucky indeed to have him as the authority we can go to!

[Commander 147]

Ebb

For the model of Odyssey battery I plan to use the battery is a PC1800 and it is sealed and does not need a battery box of any type. Here is a paragraph from the Odyssey website describing the battery I'm planning on using.

"Using pure-lead technology, the new ODYSSEY® PC1800 has up to a 15 year float life and lasts up to 10 years in engine-start applications. The sealed Drycell™ construction prevents external venting, which eliminates terminal corrosion and results in high charge acceptance, increasing the vehicle's alternator and starter lifespan. Also due to its sealed construction, the PC1800 is certified non-spillable by US DOT and IATA for unrestricted, safe shipping and can be mounted and operated in any position. ODYSSEY® is explosion proof, no other manufacturer can make that claim, and provides years of safe operation."

Since my commander does not have the bridge deck I plan to use four of these directly under the forward end of the cockpit. They will fit behind the cooler I plan to use as a step to go down into the cabin. I will shield the terminals to avoid accidental shortages.

If you are actually interested in looking into the batteries further here are some avenues to pursue.

I know the folks at Electric Yacht could put you in touch with at least three indiviuals who could give you their opinion based on the experiences they have using the TPPL batteries. They have sold the batteries to some of their customers and chargers for the batteries to other people (like me). If you are really interested in checking them out further that would be a good way to get names of people using them. Call Scott McMillian at (763) 370-2605 and he can probably help you out. Also you could call the folks at Odyssey and they could give you lots of names of people using the batteries. Ph (954) 766-2570.

Here is the Odyssey website link.

http://odysseysoutheast.com/pc1800-battery.php

[ebb]

Jerry, thanks for the leads and the tips

If I got two of those 12V PC1800-FT and put one on top of the other on their sides, they'd be a tight fit under the cockpit, but close to the space (footprint layed out for 3 Group 27 or 4 GC.)
Two of the rack mounts reserve capacity total 16Ahrs @ 25A. Those honkers weigh in at 265lbs.
At 130lbs each, how do you lift them in and out of the companionway? No hooks or handles. If you had a herness how would you get it around this lead weight?

Odtssey has a PC1700 G27 RV battery that 3 would fit perfect, as expected.
Those three RVs would total 7Ahrs reserve capacity @ 25A.
Three RVs weigh in @ 183#
But at 61lbs each I might be able BY MY LONESOME lift them out of cabin.
No guarantee, but at least I could push them around.

Four wet cell 6V TROJAN T-105 GolfCart batteries, each 64lbs, Xs 4 = 256lbs. There is 15Ahrs @25A reserve capacity (at 12V.) The footprint is almost the same as the three RVs from Odyssey.
Interesting numbers:
PC 1800> 16Ahrs @25 A..... 265lbs
PC 1700> 7Ahrs @b 25 A.... 183lbs
Trogen> 15Ahrs @ 25 A...... 256lbs

Bet there are more Trojan wet cells at sea than Odyssey AGMs.
Haven't compared costs. But the ratios are interesting.
One net vendor (ebatteriestogo) sells Trojan's 6V AGM GC for $300, free shipping.
The wet cell goes for $139 but you have to pay trucking. Trojan doesn't talk about TPPL
however they are the inventors of the GolfCart battery - they have been around awhile.
And if you have a 50/50 chance of your bats doing what they are advertised and they last only 5years, they are available wherever they play golf on the planet.
All say the batteries last 10 years. Thin cell, wet cell, agm.
Defender has pricey ($81) ABYC approved cases for 2 GCs. Unfortunately the OD dimensions are 18.25L X 14,25W X 14"H - too HUGH for a 2-bank footprint for litlgull.

That said: two PC1880-FC units are looking more atractive every minute!
WHAT DO WE NEED TO CHARGE THESE BABIES? Don't think the OB alternator has a chance.
CAN IT BE DONE SOLAR ? ? ?
__________________________________________________ __________________________________________________ _________________________
Odyssey PT1800 about $8oo each. TPPL technology. 15yr life
Trojan GC2 AGM about $300 each. Thick plate tech. 10yr life.
Plus the support charger, regulator, gages.

[mbd]

Hey guys, I ran across this on Yahoo's very active Electric Boats Group. Posted at the beginning of April 2012. "Eric" seems to be THE guy on the forum.

This link is below, but I also found it rather useful:
http://www.vonwentzel.net/Battery/00.Glossary/

************************************************** *******

First of all, lithium batteries should never be drained to 0%, using my
Thundersky LiFePO4 prismatic cells as an example, a single event of dropping the
cell voltage to 2V can ruin that 3.2V cell forever. This intolerance to
complete discharge is one of the drawbacks to lithium cells in EVs and electric
boats. That is also one of the reasons that many people run Battery Managemnet
Systems (BMS) that will prevent over and under-voltage situations by
disconnecting the batteries before they are damaged.

So for our purposes, the following dicharge levels are what most of the members
here agree provide an acceptable balance of usable capacity and battery life.
Flooded batteries (FLA) can be regularly discharged to 60% depth of dicharge
(DoD).
AGM batteries are good to 70% DoD.
Lithium cells are good to 80% DoD.

Like James said, you also need to consider how fast you drain your battery. We
all know that a battery that will deliver 200Ah at 10A (20 hour rating) will
deliver less at higher discharge rates. You can see that in the manufacturer's
spec sheets. Using the Trojan SCS225 12V FLA battery's specs as an example,
it's 20 hour rating is is 216Ah, at 25A it's down to 225 minutes or 94Ah and at
75A the battery capacity to 100% discharge is 57 minutes or less than 72Ah.
http://www.trojanbattery.com/Products/SCS22512V.aspx

My first post here about different battey types and Peukert's Effect was back in
Nov 2009 (post # 12716), but I've refined the explanation each time it comes up.
Here's the latest version "Choosing a battery type" from Jan 26 , 2012 (post
#20750)

===================================
Choosing a battery type for your electric boat conversion can be difficult.
Here's some information that is generally accepted on this board. The product
specs from battery vendors don't tell the whole story.

FLA (flooded lead acid) batteries are typically run to about a 60% DoD (depth of
discharge). Some people go deeper, but many consider this depth to be a good
compromise between energy delivered and maintaining a long life, measured in
charge cycles.

AGM (absorbed glass mat) batteries can be discharged to the 70-80% range. I
generally consider a 70% discharge for AGM systems. Both FLA and AGM weigh about
the same for the same rated capacity.

Lithium Batteries (LiFePO4) can be discharged even deeper, for range estimates I
use 80% DoD to keep a small safety reserve. LiFePO4 batteries are about 50% the
weight of lead/acid batteries for the same rated capacity.

Then there is a trait called the Peukert Effect, this describes a battery's
decreased ability to deliver energy at higher amp loads. I won't go into the
math here, but that loss is predictable through Peukert's equations. Brace
yourselves; it's going to get technical for a while.

In fact, the concept was known for many years before Peukert was able to
quantify the relationship between the load and capacity lost. Here's a link to a
page that explains the Peukert Effect in greater detail:

http://www.smartgauge.co.uk/peukert2.html

The content can be a little difficult to work through, but it is correct. There
are additional pages that provide validation of their version of the formula,
where the results can be verified against the published specs of almost any
battery. If you don't want to work through all of the math in the middle of the
page, the second to the last paragraph refers to how different battery types
have different Peukert's Exponenets and what that can mean.

If you can accept that different batteries can have different Peukert Exponents
depending on how they are made, then the following link shows graphically how a
different Peukert Exponent affects the available capacity of different
batteries. Look about halfway down the page, in the section labeled "The Peukert
Effect":

http://www.vonwentzel.net/Battery/00.Glossary/

Finally, while few manufacturers publish their specific Peukert Exponents, some
do and some other numbers have been published for common batteries. Peukert
Exponents are typically calculated through empirically measured capacity at
different loads. Here are a few examples (values closer to 1.0 are better):

Trojan T-105 = 1.25
US Battery 2200 = 1.20
Optima 750S = 1.109
Thundersky LiFePO4 = 1.03

So what does this mean in the real world? Let's pick a battery bank size of
10kWh (208Ah @ 48V) and a constant load of 2500W (52A @ 48V). That will drive
most of our boats to somewhere between 4 and 5kts, your results will vary.

The simple math would indicate that there are 4 hours of capacity at that
discharge rate in the bank to 100% DoD, so FLA batteries like T-105s would have
60% of 4 hours or 2.4 hours of usable range. Likewise AGM would be 2.8 hours and
Lithium would have 3.2 hours of usable range. But this is where Peukert's effect
raises its ugly head.

FLA with PE of 1.25 – 10kWh to 60% DoD at 2500W = 1.60 hours (that's a loss of
33% to Peukert's Effect)
AGM with PE of 1.1 – 10kWh to 70% DoD at 2500W = 2.38 hours (15% lost to
Peukert's Effect)
LiFePO4 with PE 0f 1.03 – 10kWh to 80% DoD at 2500W = 3.05 hours (less than 5%
loss)

You can see that AGM have almost 50% more usable range than T-105s for this size
battery bank at this load. Reducing the load (slowing down) reduces the effect
and speeding up makes it worse. Even though quality AGM are about twice the cost
of T-105s, the extra usable range makes them a very good alternative. Add in the
much lower self discharge rate so that constant maintenance charging is not
required and they look even better. People also recognize that AGMs seem to last
longer in the real world and now the AGMs are cheaper in the long run. If weight
is a concern, then LiFePO4 is the way to go. The high price per Ah can be
intimidating, but you can reduce the Ah and achieve the same range, saving money
and even more weight. Let's do the math for a battery pack that has a 2.5 hour
range at 2500W.

FLA – 14.25kWh to 60% DoD at 2500W = 2.5 hours = 633 lbs, cost about $1500
AGM – 10.5kWh to 70% DoD at 2500W = 2.5 hours = 520 lbs, cost about $2500
LiFePO4 – 8.25kWh to 80% DoD at 2500W = 2.5 hours = 200 lbs, cost about $3500

So now the lithiums are only 2.3 times the cost of T-105s but they are less than
1/3 the weight for the same range at this load.
So for most boaters, I recommend AGMs as a good balance of price to range.

So the bottom line is: it's your money, your boat and you know how you use it.
You get to figure out your priorities and pick the storage system that best fits
your particular needs and constraints.
========================================

So you can see in the last table that 8.25kWh of LiFePO4 batteries
delivers the same usable capacity as 14.25 kWh of regular flooded batteries at a
2500W load.

Notice that I'm not talking in Amps, Ah or Voltages any more. This math works
for any voltage, 12V, 24V, 36V, 48V, 144V, it doesn't matter. Even I was
surprised to find that out. Since the boats in this group are a bunch of
different voltages, it is easier to compare them in Watts because Watts are a
more consistant measure.

Fair winds,
Eric
1964 Bermuda 30 ketch, 5.5kW Propulsion Marine drive, 8 kWh Lithium batteries
Marina del Rey, CA

[Commander 147]

Mike

Thanks for posting that. I found it very interesting and appreciate you posting it. I had through conversations with the electrical engineer that I bought my system from already settled into AGM batteries but a hybrid version of them called TPPL which stands for Thin Plate Pure Lead technology. This type of battery has very high amerage draw capabilities and very long running capabilities. In addition you can draw it down safely to a deeper level than most AGM batteries. These batteries fall somewhere between the AGM specs on your post and the lithium specs.