Baqon drop-in LiFePo battery systems with BMS

[DeepFrz]

Interesting. The author is saying he has lost 10 - 15% capacity in one year and is about to do another test to see what happened in the 2nd year.

[Maine Sail]

Originally Posted by DeepFrz

Interesting. The author is saying he has lost 10 - 15% capacity in one year and is about to do another test to see what happened in the 2nd year.

He is actually saying he never got a baseline to measure against and only has a WAG from GBS as to what they feel it should have been. His batts are also in a hostile environment for any battery and Bob has acknowledged that. His next test will be much more telling of any true measured capacity changes..

[DeepFrz]

Okay, but he is down approx. 15% from rated capacity, 10% from what the manufacturer thinks it should have been.

[CarlF]

This seems like a pretty big deal. A drop-in, engineered solution with a five year warranty from a US address.

Lithium batteries were not going to really take off on boats if you had to hire Maine Sail to machine an absolutely gorgeous case for you. Or if you had to learn what "top balance" meant.

Of course, this battery pack might not live up to it's advertising (and I sure wouldn't rush out to be a first buyer) but I would guess that reasonably priced drop-in lithium battery packs with on-board BMS for boats will be common within two years.

[Ex-Calif]

9Kwhr at $3,550 might make a lot more sense.

- 3000 cycle rating
- 5yr prorated warranty
- With an 80% discharge ability giving 750a/h

Please someone buy this, drop it in and let us all know - LOL...

So let's play a game! Suppose we consume 200 amps a day on the boat. Let's also suppose I can shove 200 amps a day in via 100% solar - i.e. let's suspend the charging discussion. I get those amps over an 8 hour day. So for 16 hours of my 24 hour period I need battery current.

200 X 2/3 = 132 amps needed overnight every day.

Over 5 years I get 132 X 365 X 5 = 240,900 amps
$3,550 by 240,900 = 1.5 cents per amp used

For the pragmatic it's really calendar cost of cruising so...

$3,550 / (5 X 12) = $59 a month for storage

There will be variation and sometimes I will draw the bank down more if I don't get sunny days but this battery on average this is the number.

Now This bank say has 80% usable capacity = 560 amps so this battery is averaging a 132/560 = 24% draw down of available capacity.

I theory I could use a smaller bank or work it harder to get better efficiency numbers.

Now What about a Trojan 750 amp bank?

My choices are (6 X 225) / 2 = 675 or (8 X 225) /2 = 900 - I could say that we have to at least meet 750 but real world I would probably select a 675 bank.

I can see these around $150 X 6 = $900

But I have only 50% useable so my discharge is 132 / (675/2) or 40% on average. This leaves me pretty much no margin for cloudy days and on cloudy days I need 200 amps! I think I am back to a 900 amp bank!

(8 X 225) / 2 = 900
8 X $150 = $1,200

This gives me 2 days no sun capacity. I may not be comfortable with that but let's say I am and will run the engine or do something else.

$1,200 / 240,900 = 0.5 cents per amp used
$1,200 / 60 = $20 a month

But... How long will either battery live? The Trojan has a 36 month pro-rated warranty. Let's assume that is the life?

132 X (365 X 3) = 144,540 amps used

$1,200 / 144, 540 = .8 cents per amp
$1,200 / 36 = $33 per month

So there's some numbers to chew on. I'd be interested to hear some thoughts around the lifecycle of the batts - if the Trojans do 10 years on your boat sure they get real cheap. But will the Lithium go 10 years?

- Trojan bank weighs 496 pounds and has a big footprint
- One single Lithium battery - what if it fails? No redundancy
- The single Lithium weigh 252 pounds with a smaller footprint
- Could I do 2 X 2.6 Lithium @ $1,430 and 70% discharge?

5200 / 12 = 430 a/h X .7 = 303 useable
$2860 / 240,900 = 1.1 cents per amp used
$2860 / 60 = $47 per month
This bank with redundancy weighs ~180 pounds

Cost wise I am not sure Lithium makes sense at this point...

[Rick R]

Thanks for the calculations Ex-Cal. There are other items that need to be factored in to the equation.
As Maine Sail explains in his not yet finished report, buying the lithium batteries is only the first step. Because the charging voltages are so different from old style lead batteries, the charging system(s) must also be modified.

On our boat, the engine driven alternator is internally regulated and can not be reset. But the alternator could be modified to use an external regulator, $$$, then there is the cost of the external regulator, more $$$. Our backup battery charger can not be adjusted to charge lithium batteries, and it would have to go, so I would either get along without or buy a new one, more $$$. Our primary charger, a Victron Multiplus can be adjusted, but I would either have to purchase a thingy that allows the multiplus to talk to my computer, or hire a tech to make the change, even more $$$.

I don't have a price for all these changes, and probably every boat will be different anyway, but you can see that the cost of buying the lithium batteries is only part of the price of changing over. It is not quite as simple as dragging out the old lead batteries and connecting the new lithium in their place.

However, it is obvious that this is a technology that is coming. It is just not quite here yet.

[Maine Sail]

Sorry guys but as has been pointed out numerous times in other LFP discussions there is no such thing as LFP "drop in" no matter how much these companies want to get into your pocket and no matter how much we "wish" for drop in its not going to happen the way we wish it to..

Ask yourself this.

What happens when you go over their HVE limit and the main contactor opens to protect the bank? Yep, you just blew up your expensive alternator.

How does this or any single contactor "drop in" system deal with breaking away wind, solar, shore charger and alternator safely while still ALLOWING the use of the battery bank? It does not because it is an inappropriate, one size fits all, approach.

Painted steel end plates and draw beams, are well suited to a fork truck perhaps, but a boat...?? You going to have the height for those handles?

What is the quiescent draw of that contactor? Who's contactor is it? What type of disconnect loads can it handle?

What is the max charge current during shunt balancing? Do they even know? Have they tested it? What temp do the shunts get to when balancing high charge loads? At 14.4V this bank will be actively balancing quite a bit. There is zero need to charge these banks at 14.4V other than opportunistic marketing. There is only down side to this type of charge voltage, no upside other than to put money in Balquon's pocket.

The CEO of Balquon told me over two years ago flat out 14.0V max charge voltage for the "application". I then tested, and tested and tested, and tested and came to the conclusion that 13.8V was an even better bet. Of course 14.0V is still far safer than 14.4V and will create far less balancing issues.. The CEO told me 14.0V and they sell one for 14.4V and the Chinglish Winston manual says 14.6V to 14.8V. Fun stuff huh....

You guys figure it all out, I already put hundreds & hundreds of hours in figuring out safe charge voltages for frac "C" LFP. Some companies are getting it, others are opportunistic...

Why have they dropped to 14.4V from their other recommendations as high as 14.8V, which BTW is pure insanity?? I suppose because they are starting to get it, just not fully get it quite yet... The other option is that they want you to believe these are in fact "drop in" and by selling you something that charges at 14.4V they will have more opportunity to pry your money from you because many chargers,regulators and such can easily do 14.4V but not 13.8V to 14.0V...

There is NO NEED for 14.4V or anywhere even close to that other than "drop in" marketing.. It only adds dangerous levels of heat in the shunts and creates the balancing systems own need to be there doing the balancing. If they really told you how to charge these batteries safely yet very effectively then you would need to spend a lot more money on other systems and you'd price yourself right out of a sale.

One "drop in" company already apparently learned the hard way. They used to allow 14.4V - 14.6V.. All of a sudden they now only allow a max of 14.0V.. Go figure...... But still good to see they are finally getting it....

Any well executed LFP installation on a boat will be wired for a charge bus and a loads bus. On some boats this is considerable work. HVC & LVC level protections and warnings will ideally occur BEFORE the main contactor opens and disconnects the bank. I prefer HVC to be relay disconnects, of all charging sources, at the warning level, and this on top of audible alarms. These break away systems are well before the main contactor opens totally disconnecting the bank. This allows a charge device to fail yet you still retain use of the bank for discharge.. Breaking away charge sources should be be done properly so equipment is not destroyed in the process.

Most "drop in's" do not account for any of this and, as is typical of Balquon, they have no available technical data to see if the BMS has additional ports or programming to account for this type of installation.? Done incorrectly you can easily destroy an alternator and even some controllers and wind gens.

A good marine LFP system incorporates all the necessary items for a marine installation that may have multiple charge sources to deal with. This is why "drop in" with a single contactor does not work. It is a system not just a battery. We are not in a warehouse with one lone charger we have multiple charge sources to contend with and any good marine install should deal with them and do so safely.

Look at the Genasun system if you want an idea of how one of these installations should be done.

My own system was done for a LOT LESS than the Balquon "drop in", and done to a higher standard, and is focused on actual use at fractional "C" levels, but it is far from drop in........

Sorry for the rant I just hate it when the market wants something that can't really be done and some company does it anyway just to grab money... Caveat emptor on any LFP drop in.

[a64pilot]

So Maine Sail, build us a an LFP bank, I need to replace my stock Alt, and my old as heck charger anyway.
I understand the infrastructure to support an LFP battery has to exist first, and this ain't gonna be cheap, but I think there may be enough people out there to support such a venture.

If the market exists, somebody's gonna do it, some will just do it better than others is all.

[SV THIRD DAY]

Some may call it a Rant.....
But I call it being the Voice of experience and reason MainSail.
Sometimes it's a lonely and thankless job, but it's appreciated!

[remiss]

Accepting the fact that there is no drop-in replacement for lead acid (although engineering one would be interesting -- and not impossible, but probably not cheaper than buying a proper charger + etc). Li-Ion need constant current, then constant voltage, not absorb, float. Anyway. That's not what i wanted to say.

Statistics is a wonderful thing and it depends on how you look at stuff. Calculating on Ex-Califs numbers a different way :

trojan 9*225ah = 6.1kWh useable (ignore 9, just to make comparable) 9 * 150$ = 1350$
1500 cycles @ 50%
252kg
0,147 $ / kWh

balqon 9kWhr = 6,3kWh useable = 3350$
3000 cycles @ 70%
106kg
0,177 $ / kWh

Now.. These cycles are what they say.. Who knows what they actually are. However, I came across a couple of interesting things while researching the numbers. This is from Trojan:
"As a rule of thumb, for every 10°C increase in temperature the reaction rate doubles. Thus, a month of operation at 35°C is equivalent in battery life to two months at 25°C"

And the pbase-guy: "Of course the average lead acid battery on boats is often dead well before 150 cycles and they rarely if ever even come close to the "lab rated" cycles. Do the math on your own bank, be honest about it, and see how many cycles you had, to 50% SOC, before your bank needed replacement. Most boat owners are shocked when they do this math."

So, if it's a bit hotter than the batteries like and maybe the rating is a bit overrated, 17 cents might not be too bad.

[SV THIRD DAY]

Originally Posted by remiss

Do the math on your own bank, be honest about it, and see how many cycles you had, to 50% SOC, before your bank needed replacement. Most boat owners are shocked when they do this math."
.

After 7 years of full time Living Aboard/Cruising at anchor or on a mooring, I did the math...which is why I'm installing a 400AH LiFePO4 Bank!

I sure wish I could have some of the generator life and fuel costs back in having to deal with the Lead Acid Battery charge profiles...and if you don't know what that means...well then you haven't Lived Aboard or Cruised off the Dock and away from shore power.

The shitty charge profile of Lead Acid HAS to be taken into account in the equation here...the generator run times and fuel costs needed to deal with bringing your Lead Acid Batteries back up to a healty full Charge frequently to keep them from dying on you are not small issues and to me were a big factor in switching from Lead Acid to LiFePO4!

[a64pilot]

OK,
So lets drop the name "drop in"
Well call it "turn key" then.
Somebody market a system if you will with a recommended Alt, voltage reg and charger to go along with the battery they will sell you.
You smart guys determine what that means, how it's done. Those of us that don't want to will pay you for your work. I promise (meant to be funny)
40 yrs ago when the first turbine crop duster was built, everybody laughed. There was simply just no way you could get one of those things to pay for itself, they were just so expensive it didn't make sense, and that was when gas was cheap.
Try to find a new production piston engine crop duster now.

When viable LFP systems hits the market, slowly over time LA will go away, may take 40 yrs, who knows.

[SVNeko]

Originally Posted by a64pilot

OK,
So lets drop the name "drop in"
Well call it "turn key" then.
Somebody market a system if you will with a recommended Alt, voltage reg and charger to go along with the battery they will sell you.
You smart guys determine what that means, how it's done. Those of us that don't want to will pay you for your work. I promise (meant to be funny)
40 yrs ago when the first turbine crop duster was built, everybody laughed. There was simply just no way you could get one of those things to pay for itself, they were just so expensive it didn't make sense, and that was when gas was cheap.
Try to find a new production piston engine crop duster now.

When viable LFP systems hits the market, slowly over time LA will go away, may take 40 yrs, who knows.

+1 Or at least list the actual items that are needed. Eg, what the hell do I use to cut out the alternator in a way not to fry it? etc.

[Colin A]

OK O'm going to drop all industry connections for a moment and speak from my personal side here.
I would think it would be possible to develop a drop in Lithium system. It would just be some what unweildly and slightly complicated to build. But you could build a bank with an attached BMS etc The bank would have integrated circuit protection and disconnect solenoids, it would also need a BMS and cell logging. You would than need to have separate charge and load buss connections (connected to separate disconnects). Ideally you would than also connect your charge sources to these busses and the bank would have built in voltage regulations and possibly current limiting. So again in this ideal scenario the bank would have different setting for different inputs. Say input 1 is an alternator. You could have a field control on this input to prevent damage to your alternator, you could also would also be able to set its input voltage etc. Than input 2 would be solar this could have a built in MPPT charge controller or an external one could be used but the voltage would still be regulated by the bank if need be. Than we would set input 3 for a battery charger and again the unit would correct the input voltages. Of course this than runs in to trouble with your battery charger programmed charging regimen so we need to have a program that tricks the charger into staying in bulk charge etc or maybe we should just make the AC charger part of the package as well. We should also have a battery monitor that plugs into the system with a nice WP mount.

And then we give the sucker an ethernet port and a web accessed programming GUI.

And the more I think about it the more things need to be sorted.

In all likely hood we will see more chargers/regulators with settings or programming to allow for Lithium once this happens I see the rest of it becoming much easier, of course it seems some charger manf are still figuring out charging on LA so who knows how long this may take.

[a64pilot]

It can't be that complicated, How is the DIY crowd doing it?
BMS should take care of all charging needs won't it, or what's it for?
I have a Silent Submersion Magnus SCUBA "scooter". It has a 1KW Li-PO battery and a BMS as part of the battery pack, BMS takes care of all charging and discharging, low voltage cut out etc