MacGregorSailors.com

Probably been discussed but been away for a while and been some discussion elsewhere and thought they would be ideal for the Macs especially those who want lots of toys.

We are still using VRLA in our new mode of transport and think they will outlast me but think prices are coming down and when compared realistically they more than compete in price anyway.

I looked at some EV 12V lithiums when I did my upgrades last year' apart from a weight saving and requiring less number I could find no advantage over AGMs. You need 50% more AH in AGMs to get the same usable discharge cycles. i.e a 90AH Lithium = a 135AH AGM.

Pros;
Light Weight
Can discharge regularly to 25% no degradation in life cycles.

Cons;
Still expensive
Requires a special monitoring and charging system to not over/under charge again expensive
Can be permanently and irreparable damaged if above fails or does not work properly
They can be a fire risk

I set up my solar & AGM for the cost of just a 90ah lithium battery, I got my 1400W petrol generator and a 40A charger for less than the cost of a lithium charging/monitoring system alone

I really like the idea of lithiums and if I was living on a boat 24/7 they would be on my must have list. But for a Mac not yet

They can be a fire risk

Yeah, they brought down this 747.

https://en.wikipedia.org/wiki/UPS_Airlines_Flight_6

And some other aviation incidents, IIRC.

Just a digression, not necessarily saying they are overly dangerous.

I thought one of the advantages of lithium was the amount of power they can deliver quickly. Not something we care about. Most of us want max storage amps.

--Russ

I use two 100ah strings of these LiFePo4 batteries in parallel: http://elitepowersolutions.com/products ... ucts_id=92, for a total of 200ah. I have cell balancers on each cell (Total 8..), a 50 ah breaker on the whole package, a Midnite Solar The Kid Marine charge controller, and 2x240 watt 24 volt solar panels on the back of the boat.

Advantages with the LiFePo4 cells are
light weight,
rated 2000 cycles to 80% DoD,
no fire hazard (cells will vent if over charged or shorted long enough but will not thermal runaway like lithium manganese/lithium cobalt),
no peukert factor (Batteries will store all power delivered to them so no wasted power to top off last 10-20%),
no 4-8 hour trickle charge to top off like lead acid,
no problem to store batteries for months/years at full charge, or half charge, or 10% charge.
Nominal voltage over 90% of the discharge curve is ~13.2 volts, which makes all of the electronics happier (especially over long runs and higher current applications)
Battery system requires no thought other than 'do not over discharge' I can monitor from my charge controller via shunt how much I've used. Average night on the boat, with cockpit lights deck lights cabin lights anchor light, fans, chart plotter, fm radio, vhf radio, refrigerator @ 34deg, lots of beers -- crash out at 10:30-11:00, next morning I'm down to 70-75% charge. By 11am next day solar has it at 100%.

Disadvantages of the LiFepo4 cells:
LiFePo4 hates high temperatures and they will reduce your cycle life.. recommend not storing batteries in boat when temperatures go above 105. In Arizona this is a consideration..luckily batteries weigh less than LA equiv
LiFePo4 can be used to draw from while frozen, but doesn't like to be charged while frozen. Use/warm before charging...
Must carefully design system so that charge controller does not over charge string, and that each cell has a balancer on it to bleed power if it goes to high.
Must take into consideration occasional balancing charges to force balancer bleeding of slightly high cells
Must choose conservative "100% full" charge so as to not push limits of the cells... i use 14v for my strings, some prefer 13.8 or even 13.6 for longer life. Manufacturer suggest 14.2 or 14.4 but this will prematurely degrade lifetime of cells.
Must carefully design system so that you do not over discharge battery pack. Either monitor actively or build monitoring and LVC into the system. Personally... 200AH gives me enough headroom that I don't really concern myself with it to much... I check charge state regularly when using the system, and occasionaly check it when it's parked on the side of the house -- but the loads are so low when the boat is in "parked, maintenance" mode that I would probably get a month out of my 200ah before the batteries were in trouble. Some status LED's and the charge controller...

End book post. Summary: LiFePo4 requires LESS maintenance for me than LA, because I dont have to care whether or not it gets to a full SoC, and the cycle life is high enough I dont have to worry about buying new ones for several several years.

Great post thanks

Yes, thnx, Texlan, good comparison info without making my eyes cross from technical info this subject usually introduces...

Good post Texlan
Sort of backs up what I have been hearing over here but didn't pick up about the heat and cold, thought more would be using them for air cond etc as there were a few toying with them a while ago.

Think it would have been a good option for our old boat as we basically lived on it 3-5 months a year, especially with trying to keep batteries up to the fridge, being able to not worry about keeping full charge most of the time would be an advantage too as especially would be the weight or lack of.

Don't think the price is so different though when you consider all the facts e.g. the huge number of cycles and longevity although have heard it mentioned that the time as in calendar time might not be as good as suggested?

Definitely a good option though in a lot of situations where you want quick recharge and low weight without worrying too much about voltage drop.

Glad I could help, guys. I am an extra class amateur radio operator and have been playing with LiFePO4 for years, to me it only makes logical sense to use them in this application. You lose so much power from charging lead acids (30%?) in the absorption charge phase that it offends my sensibilities.

I think the rough calendar life in past examples has been largely a factor of heat and floating at too high a voltage for too long.. between 13.2v and 14.4 on a 4 series string is only about 1% of the power in the battery... why burn out probably more than half your cycle life for that extra 1%? The documentation needs to be better from the manufacturers..but I'm not sure they even know, as they make them and ship them around the world -- they don't actually use them.

Sean

I use two 100ah strings of these LiFePo4 batteries in parallel: http://elitepowersolutions.com/products ... ucts_id=92

Gee finally something available in OZ that we are not ripped off on.

These are the exact batteries I looked at and they were less expensive given the exchange rate here at $498USD yeah!! for Chinese Batteries

http://ev-power.com.au/webstore/12v-lif ... odule.html

I have been using it for about 3 years: LiFe 100 Ah weighing 12,5 kg, and got rid of the old big lead one 200Ah weight 66 kg. The LiFe-battery 100Ah gives nearly as much energy as the old lead 200Ah.
I only have 1 battery using it for enginestart and all the other things. For enginestart backup I have a charged reserve package used for cars and weighing 3 kg. So I got rid of a lot of cables you use for 2-batteries-system. It has worked fine for 3 years and I have never got out of battery-power.
But it is very importent that you have a volt-meter installed so you do not get under 10v, then the LiFe will be destroyed.
It is as important if you have a solar-cell installed that you have a regulator which transform voltage over 16v from the solarcell to ampere. Or else the LiFe will be destroyed.

hah Kadet, way to go!

When I first started fooling with LiFePO4 I looked at several "manufacturers" and asked the ultimate question: are they all made by the same Chinese company?

The first one i got was a GBS 20ah 4cell pack from Elite Power Solutions because (at the time) their warehouse was literally 3/4ths of a mile/1.2km from my house. I thought: how can i go wrong?

Since then they've been my go to solution for prismatic cells. I'm sure they only cost $50 in material and labor to manufacture -- so a shout to someone who found them at a more reasonable price

such is capitalism!

Speaking of capitalism... i just ordered a haswing protruar 2hp motor, and the stuff to turn my two 100ah 12 v packs in parallel into a 100ah 24v pack, as well as several 24v to 13.8v converts to supply my 12v loads. I recently had a bad experience with my yamaha 9.9 high thrust on my '26s in a about 15knot crosswind at the local boat ramp dock.. the 9.9 cavitated before it could provide enough thrust to rectify my situation.... i'm thinking that the lower hp, but slower higher thrust electric (with more maneuverability) will provide for a better solution.

We'll see, wish me luck...

if i can add to this forum.
I will buy a mac or tattoo soon , yes liveaboard , but i will use it as well for a fith wheel ...
It may sound crazy, but we will have enough space after the mods, especially for what we want to do with the whole thing.
On top, we are checking to get at first a pickup truck (as stupid as they are now) and later mod it as hybrid electric, unless a SUV hybrid shows up. We could buy a nissan leaf or other and use it for a while , then switch the batteries toward the boat.
For now, using AGM and LOTS of solar and wind turbine power is my first bet.
I wanted to buy the leaf at first for my house bank , but i decided to sell my house.
If i could plug my boat into a microfit program in Ontario, it would be interesting , but not possible i think.
One way to add lithium into a mac would be to get a powerfull Torqueedo or a couple of them. I looked for the most powerfull, instead of a 90 hp gas. Wow , prices are mad. Another outboard is available in Dania , FL, but too powerfull. I think it can regen . Emrax is making a very interesting w/p ratio emotor (pancake motor) . It can regen.
For me, for now , it is to check prices and work with solar, wind and gas with AGM. Later as prices lower , i'll go for epower with lithium or whatever safe "mass consumer" engine. Propane is another player, the idea being to reduce breaking toys numbers onboard.
My late neihbor was part of a team who developped the lithium batteries. He was never hot on it because of fire hazard. At that time 2007.

Here is the answer for you electric drive for your sail boat.

http://oceanvolt.com/support/technical- ... ail-drives