Have to Upgrade My Battery Bank - Acid or Lithium ?

[Adelie]

Originally Posted by Lagoon4us

John i looked at this thread initially, so many pages! Was hoping an enthusiast could shortcut the discussion some.. Cheers Frank

That's the price for being an early adopter. Best practices are still not completely settled, price is changing rapidly, there is still a lot of opinion to wade thru and you pay your money and take your chances.

[downunder]

Originally Posted by Adelie

That's the price for being an early adopter. Best practices are still not completely settled, price is changing rapidly, there is still a lot of opinion to wade thru and you pay your money and take your chances.

With cell costs somewhat settled now similar to AGM and quite a lot of early adoptors out there seems a reasonable risk. Don't forget the electrical vehicle and RV users are well ahead of marine adoption. Still agree with you there is plenty to wade through but seems it is there now.

cheers

[hellosailor]

"With cell costs somewhat settled now similar to AGM"
I must have missed the memo. Last prices I saw, for no special name brand, were the same for a single lithium cell (4 volt) at the same AH capacity as a 12volt AGM battery. In other words, the no-name lithium battery of three cells would have cost 3x the price of the brand name AGM battery, and that was supposed to be a great deal.
Assuming there's really no need for a BMS for the lithium battery, which is still up for debate.

[OceanPlanet]

Originally Posted by hellosailor

"Assuming there's really no need for a BMS for the lithium battery, which is still up for debate.

No kidding...

[NahanniV]

"3x the price of the brand name AGM battery"

I think you need 4 cells ?

[Dockhead]

Glad you found a workable solution!

Originally Posted by RaySea Lady

I will probably replace them in the spring since I know that these batteries were in fact drained below 50% on several occasions.

Just because you ran your batts down below 50% a few times doesn't mean that they need to be replaced. Decent semi-traction batteries will survive quite a few cycles down to 20%, and even draining them dead won't necessarily kill them. If you spend most nights in marinas, those 8D's should last a long, long time. I would have them load tested to see what kind of condition they are in. Do you equalize them? You should be sure to do that from time to time.


As others have said, I find the energy requirements of your refrig set up to be exorbitant -- a tail wagging the dog of your electrical system. I think that for most people it is a mistake to install electrical gear on board a boat without carefully considering how it fits into your power budget. There are some very nice marine refrigeration units available -- you can have reasonable efficiency without giving up all your luxury.

It's common on large motor yachts to have "entertaining" refrigeration which is not kept switched on all the time. You might want to think about that if you ever fit out another boat for yourself (and for your admiral ). In your case, since you usually have shore power, it's turned out to be manageable, fortunately, but for most of us, some amount of autonomy is essential.

We just finished a month-long summer cruise and spent only five or six nights on shore power, and besides that, 90% of our miles were made under sail, so no recharging as a byproduct of propulsion. We managed to keep a 54 foot boat with 5 or 6 people on board most of the time running on 420 amp/hours of batteries (@ 24 volts) without any big hassle, one or two relatively short generator runs a day, and no draconian power conservation. That's with large fridge and separate freezer (making endless quantities of ice for cocktails ), inverter running most of the time, as many as 5 or 6 laptops and 5 or 6 mobile phones being charged 24/7, a lot of usage of microwave, washer/dryer, Nespresso machine, etc., etc., etc. -- all of which I'm saying to make the point that you can live in reasonable luxury on board without burning through millions of kilowatt/hours a day.

[Gene :^)]

Is it possible to keep these refrigerators, but have the AC powered air cooled guts swapped out for DC powered water cooled guts?

Then the admiral is happy with the look, fit, and style, and the captain is happy with manageable energy consumption.

Could you guys be specific on which parts to be swapped out, maybe the evaporators can stay and just change the rest?

I also understand that household refrigerators use most of the energy for heat strips, actually heating parts of the fridge to keep it frost free. Might be able to defeat or disconnect this feature when away from the dock. Then turn it back on at the dock to defrost.

Would a non frost free household fridge be at least a little better on energy than a new frostless model?


-----

Gene :^)
http://www.Strathbelle.com/

[Gene :^)]

What about adding DC powered or engine powered holding plates to the units. This could eliminate or at least reduce run time of the AC pump.

Then they could almost be dual mode, AC at the dock and holding plate at anchor. With inverter powered AC to assist when the plates need a little help keeping up, like when the fridge is opened and closed a lot.

I read a bit more about the frost free heaters inside household refrigerators and they could definitely be disconnected for a couple days at anchor or at least until the next generator run. No need to defrost when on inverter power. Maybe a relay in the circuit that opens when shore power or generator power is off.


-----

Gene :^)
http://www.Strathbelle.com/

[kefroeschner]

Someone asked for a citation regarding the energy density of NiMH et al. Here is what I found on Wikipedia, a usually credible source, data from 2011:

Type MJ/kg MJ/l
Li-Ion 0.72 0.9 to 2.2
NiMH 0.29 0.54 to 1.08
Pb Acid 0.1

The first column is Megajoules per kilogram, and Li-ion is the clear winner -- Lithium is the lightest (least dense) metal, thus its use in RC airplanes, cars, laptops etal.

The second column is Megajoules per liter, i.e. how much energy can you get from a given volume, never mind the weight. Here the data for Li-ion and NiMH overlap, with Li-ion still leading but not by much. And given the relative robustness of NiMH compared to Li, I think it deserves more attention than it gets.

We use NiMH "D" cells in our products, 1.2v with 10 Amp hr capacity (not a mistype, 10,000 mAhr in the more usual units) for about 2 US$ each.

You can get more current data from sites like allbattery.com.

[randude]

On the issue of use level on deep cycle batteries, as David Snead says, author of Living on 12 Volts with Ample Power, "If you do not use the capacity of your batteries you are just paying for lead acid ballast"

On the issue of Lithium Batteries, they are very expensive still. A single 12 volt battery could cost you $6500 USD.

[ebaugh]

Lithium is coming down in price....at least one example:

It's been posted before...but Balqon recently started distributing Winston lithium phosphate cells in the US. They are advertising a 1000 AH 4 cell pack 12.8 V pack for $3450 and 700 AH for $2640. Since 70-80% of capacity is usable, that's probably less than AGM today.

Do a web search on Balqon, go to their Estore, and look at their HIQAP series.

I recently finished a lithium install with another brand just before these hit the US market. My luck... I'm dying to find out if they are really shipping and how they work out. It's a great deal on paper, and represents breakthrough pricing. But this is new technology for boats, so you will be an early adopter, and all that goes with that.

[randude]

I was tasked to do a life cycle coast analysis of Lithium Polymer Batteries. My source was Corvus Energy in BC Canada. I was never given a True Bid as he wanted me to rate the duty cycle and other things that would require my doing a life cycle analysis for him. I just wanted a price for the batteries. He quoted over the phone a price of $1000 per kw. When you look at the KW rating of one of their smallest batteries, the AT2500 that has 1200 CCA and 225 AH, the rating is 2.5kwh or $2500. Sorry for my mistake above, that number was for a larger battery.

[downunder]

Originally Posted by Lagoon4us

John i looked at this thread initially, so many pages! Was hoping an enthusiast could shortcut the discussion some.. Cheers Frank

Follow up ebaugh's post on Balqon seriously in the ballpark

The HIQAP series 700ah (equivilent to at least 1400ah lead acid) with built in BMS $2640
Balqon - Advanced Transportation Solution

or more basic

Balqon - Advanced Transportation Solution

[ebaugh]

Originally Posted by randude

I was tasked to do a life cycle coast analysis of Lithium Polymer Batteries. My source was Corvus Energy in BC Canada. I was never given a True Bid as he wanted me to rate the duty cycle and other things that would require my doing a life cycle analysis for him. I just wanted a price for the batteries. He quoted over the phone a price of $1000 per kw. When you look at the KW rating of one of their smallest batteries, the AT2500 that has 1200 CCA and 225 AH, the rating is 2.5kwh or $2500. Sorry for my mistake above, that number was for a larger battery.

No worries here, just like the concept of lithium. We've been riding a dead horse long enough with Pb batteries.

Lithium Polymer is related to, but a slightly different chemistry and has different characteristics than Lithium Phosphate abbreviated LiFePO4. LiFePO4 and a couple of very small variations are the ones mostly getting adopted today. Probably for three reasons. First they are the safest, with the least tendency to run away and create heat, second they have been widely adopted and tested in the DIY electric car market with rave reviews and third they are available in high capacity prismatic packaging suitable for low voltage, high capacity applications.

Smaller banks will be only slightly more per KWH. I paid about $413 per KWH for a 15 KWH 1200 AH pack. The Balqon ones are less at $287-$296 per KWH. If you buy cells and assemble the pack yourself, a little higher for smaller banks. At the price I paid, there are many options.

No worry about CCA anymore. I think 4 tiny 40 AH cells would start any engine under 500 cubic inches, gas or diesel. Except perhaps in a cold climate below say 40 degrees F. Then a little research would be in order. But they don't mind working in a 110 to 120 degree engine room, where lead is unhappy.

If they live up to the paper specifications they will show great life cycle cost since they are supposed to last 2000 cycles, 2-3 times lead or AGM. But this so far is on paper and in the labs.

Bob

[randude]

I will look at your sources as my customer really wanted to explore a safer and greener battery. Weight is a concern of mine, I suppose that makes me unique here. Power is also a concern, although when underway I have plenty of DC. Some of these guys with inverters could solve some of my problems if I can get beyond the cost. I will check out your source and do a true life cycle cost analysis. I am a bit irritated with the company in Canada, they were in no hurry to help me, and really don't seem too disappointed in my breaking away from them.