• Welcome to this website/forum for people interested in the Morgan 38 Sailboat. Many of our members are 'owners' of Morgan 38s, but you don't need to be an owner to Register/Join.

Lithium

It was asked I post about my Lithium planning, and why.

Currently, I have 2 group 27 batteries for house(230Ah total), and a group 24 for starting, in the factory location under the quarter birth. With each of those in its own box, and all the wires for the battery switch, and buss bars, shunt etc., there just isn't enough room for any more battery there.

I need to replace my batteries before I continue cruising. The 230Ah of Lead Acid I have now were frequently drawn down to 50% or less, and while on passage often not recharged 100%. I got about 3 years out of them. They are still somewhat serviceable, but no way would get me back to California. I considered an alternate location, in particular there is alot of space under the port side cockpit locker. But that is a lot of work, and additional expense. I live on my boat now, and no longer have access to my garage, table saw etc., so it would be a challenge.

With Lithium, I can have more usable capacity in the current space, with 1/3 of the weight, and expect 10+ year life. As expensive as they are, if I were to otherwise buy 400Ah of lead, and build a new cabinet location for them, and all the new heavy wire etc. It really isn't that much more expensive. It's much less considering a 10 year life.

The question the is, what lithiums. I am looking at drop-ins over a DIY at this point, which also have the advantage that if one of a pair of drop-ins fails I still have power just at reduced capacity. I have made some interesting observations. Most drop ins seem to use prismatic cells, with a few notable exceptions.

Renogy seems to use pouch cells. Looking at Will Prowse's (on youtube) teardown they appear tightly packed in a metal case. What happens when they swell? It otherwise seems a decent product, and I like that there is an inexpensive panel that will allow battery monitoring without the need to use a BT app. I hate needing to use my phone for everything instead of having a panel meter. They have a short warranty I think 3 years.

Battleborn and Dakota both use cylindrical cells. Cylindrical cells have the advantage of better cooling, and if a cell dies the whole battery doesn't fail. In fact, if my math is correct, a whopping 34 cells could die and the battery would still make 80 of rated capacity. (each cell is 2.3Ah so 8 cells in each 3.2V block could fail) This seems a huge advantage, and interestingly Dakota and Battleborn seem to be the only 10+ year warranties. Neither Battleborn or Dakota have a way to monitor the internal BMS.

Most drop in's, and all DIY use prismatic cells. If a single prismatic cell dies, you lose the whole bank. They do seem to be very reliable, with some reports of early Lithium on boat adopters now more than 10 years in service and still test as new.

Right now, I am leaning toward Dakota, being slightly cheaper than Battleborn, an 11 year warranty, and including a lithium charger (albeit a small one). I will also be adding a Renogy 60A DC-DC charger, so that my Alternator will be connected to my start battery, and the Renogy charger will charge the Lithium from that. That isolates the Lithium bank from the alternator and protects both the alternator and battery from damage. And, I will be adding a Victron battery meter to monitor the Lithium bank, sold by Dakota and they provide the programming details to make it accurate.
 

Tim Eichel

Member
I am very interested on how this goes. Please keep us informed. Someone on this forum (Jeff Lovett) used the area in front of the galley sink, under the port settee where that little drawer is located. He removed the drawer and built a battery box. I think they were able to get 6 golf cart size batteries to fit.
 

jimcleary

James M. Cleary
Warren

I'm afraid that I am not up on the latest terminology concerning batteries. Are the individual cells in a lithium battery not connected in series as in wet, gel on agm batteries? How are they wired if you can have so many fail and still be operational?

Is the threat of the lithium batteries catching fire not an issue any longer? Can these batteries be charged from the engines alternator and from solar panels? I burnt out a set of Gel call batteries in 2 years because I was charging them off the boat in the winter with an automotive charger. Our last set of Lifeline AGMs lasted 9 years. They were only ever charged by the engines alternator and the solar panels.

Jim
 
Warren

I'm afraid that I am not up on the latest terminology concerning batteries. Are the individual cells in a lithium battery not connected in series as in wet, gel on agm batteries? How are they wired if you can have so many fail and still be operational?

Is the threat of the lithium batteries catching fire not an issue any longer? Can these batteries be charged from the engines alternator and from solar panels? I burnt out a set of Gel call batteries in 2 years because I was charging them off the boat in the winter with an automotive charger. Our last set of Lifeline AGMs lasted 9 years. They were only ever charged by the engines alternator and the solar panels.

Jim
The cylindrical cells are like C sized batteries, but a bit bigger. A whole bunch of them are in parallel, and then four blocks of those are in series.
Here is a very informational video. In fact, if you have a free evening, watch lots of WIll's videos.

Edit: Watching that video, the cells Battleborn uses larger cells than I expected, so fewer then 34 cells, but still more than just a few could fail and have it still make 80% capacity.
 
Last edited:

terry_thatcher

Terence Thatcher
Warren, I have 400 amp hours of Trojan flooded lead six volts, plus a Group 27 starting battery under the quarter berth. It is tight, but everything fits and is solidly in place. I designed the hatch covers so they also help hold the batteries in place and are dogged down. Lithium sounds pretty complicated if you can't charge from the engine. But the capacity increase and weight saving sounds attractive.
 
I just ran across these. If I go the DIY route, 8 of these cells would give me 540Ah, and it would fit in my current space. Weigh less than a single 115Ah lead acid battery, and have the same usable capacity as 1000Ah bank. And at a total cost of around $1500 with a BMS. Holy Cow.

The "too good to be true" alarm is ringing, but it is certainly something to look at.
 
Warren, I have 400 amp hours of Trojan flooded lead six volts, plus a Group 27 starting battery under the quarter berth. It is tight, but everything fits and is solidly in place. I designed the hatch covers so they also help hold the batteries in place and are dogged down. Lithium sounds pretty complicated if you can't charge from the engine. But the capacity increase and weight saving sounds attractive.
I wonder if this area is different on different boats? There is no way I could possibly fit that. I would certainly need to relocate all of my wiring and buss bars etc. if I tried, and then if becomes an expensive and difficult project again. But because of the way the floor it's sloped I still don't think I could do it. The group 24 at the aft end of the compartment is raised relative to the group 27's, and as a result there is not even enough height in the compartment for a group 27 in that spot. The 6v are taller than the group 27. Same if I tried to use the area under the port settee. My Racor, Macerator, and an aux bilge pump are all mounted in that space. Relocating those would be a complicated and expensive as the battery install.

Yes, Lithium can get complicated, especially if you go the DIY route. But once you learn and understand it, no more so than anything else. My DC-DC charger is replacing my ARC, that's basically it. It's still way easier than relocating the bank somewhere else. Also consider that you can use the whole capacity of the battery, whereas a lead acid only 50%. So a 200Ah lithium is the same as a 400Ah Lead Acid, and a 200Ah Lithium bank weighs only about 60lbs.

Right now I have 2 group 27, the group 24, 2 main buss bars and my shunt, my solar controller, my inverter, and my dc-dc charger will go in there. (which make it sound like 4 6v would work, but they are too tall.) Anyway, I can easily fit 200Ah of Lithium, and am looking at several possible ways to get more than 500Ah of lithium in the same space as my 2 group 27's. That would be super efficient if it works out.
 
For the sake of explanation. The issue with charging from the alternator. several issues. First, Lithium will take all the current your alternator can deliver, all the way until it is fully charged. Have a 200A alternator? the Lithium will take 200Amps continuously until it is charged. This will kill all but most expensive large frame alternators, a 100A alternator is only rated to provide that for a few minutes, then it is expected that as the battery charges up the current will drop. So the alternator needs to be connected to the Lithium through something that will limit the amps to something your alternator can tolerate. Lets say you have a huge alternator, the issue becomes the full charge cutoff. At 100% capacity, the BMS will disconnect charging abruptly, and the surge will blow diodes in the alternator.

The other issue is that Lifepo4 are mostly very durable, maintenance free, and tough to kill. You can cycle them thousands of times, you don't need to charge them to 100% regularly, they don't form a memory, and they degrade very very slowly compared to Lead Acid. However, what will kill them very fast, is over discharging them or over charging them. That is the main purpose of the BMS, it monitors the cells, and provides an emergency disconnect before the cells are damaged. But it is also better to charge them with a charger that is specific to Lithium. Lithium only has one charge stage, and no float stage. Floating a Lithium once it is fully charged isn't good for it. If directly connected to an alternator, the BMS should disconnect it before there is damage, but it is best to have a charger that knows better and shuts down and doesn't float the battery.
 

mpearson

Mark Pearson
Staff member
Yes, I think we must have different sized battery spaces. Sounds like I have the same setup as Terry.

Those Lithium stats are pretty darned compelling. I think I'll switch when my current lead acid batteries reach their end-of-life (a few years). Hopefully by then a small Cold Fusion generator will be an option. ;)

A thing I was reading said lead acid batteries could really only use 35% of their rated capacity ... Warren said 50%. Either way, not very good.
 

terry_thatcher

Terence Thatcher
I need to replace my 6 volts this year. But I understand them, but don't understand lithium. What about slow charging at low amps, like solar? Can a BMS system manage that to charge lithium safely?
 

terry_thatcher

Terence Thatcher
Just read John Harries discussion on Attainable Adventure Cruising. I think for now I will stay with lead acid. His concern about drop-ins is particularly compelling. You more competent electricians can change over to Lithium.
 
Last edited:

mpearson

Mark Pearson
Staff member
Wow, that “Marine” part of the web site Warren pointed to has a promo photo that sure looks like a Morgan 38.


It looks like the coach roof is slanted, though. Anyone know what that is? My guess is an older Tartan.
 
Wow, that “Marine” part of the web site Warren pointed to has a promo photo that sure looks like a Morgan 38.


It looks like the coach roof is slanted, though. Anyone know what that is? My guess is an older Tartan.
That is Sailing uma. A 1972 Pearson 36 that has been converted to electric propulsion using battleborn batteries. They have a youtube channel.

Good stuff to watch.
 
I installed a (4) 100 prismatic cells with a complete bms under the quarter berth in January of 2014.
I will called the batteries and the bms from Elite power systems in Arizona. They are installed as a single bank with individual battery switches. No starting battery. Lithium solar charger. Lithium shore power charger, Lead acid Sterling regulator. It is definitely not a drop in solution.
Expensive at the time and priceless to me now. Best bang for the buck ever. Larger than mine but same hardware.
 

mpearson

Mark Pearson
Staff member
Wow. January, 2014 makes you an early adopter, I’d say, John. Bravo. Have you posted any photos of your battery installation on the forum?
 
I will try to dig some up. FWIW:
Years ago there was a company called Ample Power. David Smead was the owner. He convinced me back in the late '80's of the futility of a separate starting battery. Mind your state of charge. If you drain the house bank your not going to be happy anyway.
 
The 4-28 pound batteries are foamed in place and the plywood cover has 2x4 spacers to the top of the batteries and is secured with barrel bolts and aluminum angle. No vertical movement
The BMS on the left, over voltage and under voltage relays, JJN400 amp Class T fuse in the negative line. This is cut in just outboard of the batteries under the quarter berth. I became obsessed with battery lugs. The wall thickness of the lugs seemed like a quarter inch buss bar. Each lug weighs about 2 ounces and required a double crimp. Just about totaled the Greenlee Heavy duty crimper.
 
I ordered my cells today. I opted for 12 100Ah 3.2 volt cells, which will make a 300Ah 12V bank. Total cost was $1700. Ouch!
I was really tempted on the deal for 560Ah for $850, but they were grade B cells from China, and although people were almost all happy, I saw pictures today of someone's trailer that burned down when they caught on fire. The CALB cells I bought have a long history in boats, and are proven reliable. Shipping to me from California, so I won't be waiting long.

Just for comparison, I priced 600Ah of AGM. Six Trojan T-105 6V AGM at $270 ea. total $1620, and weight a total of 400lbs. My lithium bank is only $100 more (not including the new chargers and BMS) and only weighs 100lbs. Plus, 600Ah of T-105 won't fit in the space.
 
Warren,
Welcome to the light side! Have you fleshed out your BMS and charging? My weakest link was the alternator. I am going to replace my Sterling alternator controller with a Balmar MC-614-H within a few weeks. Check out QuickCable lugs for really top notch battery lugs.
Best of all is that it will actually raise the waterline!
 
I am likely going to use the "overkill solar" BMS. 120A is plenty for my needs. I don't think I have ever come close to pulling 120A from my house bank, it's typically 10A or so. It's cheap and has been proven reliable. Before I leave, I might add 2 more and configure my bank as 3p4s, with 3 BMS for 360A and some redundancy.


It's MOSFET instead of contactors so it won't work for starting applications, but very simple to setup and install. A more sophisticated setup with contactors and a separate charging and load buss has a lot of advantages, but is more complex and a lot more expensive.

For charging, the alternator is connected to the start battery, and a Renogy 60A DC-DC Lithium charger will charge the house. I will have a 3-way switch at my panel OFF-30A-60A, which will usually be on 30A, unless I need a boost, or if I am motoring for days. Primary charging will be Victron solar, which has Lithium profiles and is very configurable. I will probably configure it to stop charging at 90% or so to prolong the life of the bank.

I will also have a Renogy 20A Lithium shore charger, 100-240V input so I can plug it in in foreign countries.
 
I have just hooked up my 2nd BMS120A to a 200 amp 8 cell pack just like they show in the Overkill instructions to use in a truck camper. I learned 2 things.
Lab power supplies are not reverse polarity protected and BC4 does not go to pin 4. All my screwups were done on a workbench.
Ah, the sight and smell of burning insulation kinda gets your heart pumping.

Overkill offered to replace the BMS at no charge. He accepted a 50-50 split. I suggested that the numbering should be 1-1, 2-2, 3-3 etc.
 

Tim Eichel

Member
I ordered my cells today. I opted for 12 100Ah 3.2 volt cells, which will make a 300Ah 12V bank. Total cost was $1700. Ouch!
I was really tempted on the deal for 560Ah for $850, but they were grade B cells from China, and although people were almost all happy, I saw pictures today of someone's trailer that burned down when they caught on fire. The CALB cells I bought have a long history in boats, and are proven reliable. Shipping to me from California, so I won't be waiting long.

Just for comparison, I priced 600Ah of AGM. Six Trojan T-105 6V AGM at $270 ea. total $1620, and weight a total of 400lbs. My lithium bank is only $100 more (not including the new chargers and BMS) and only weighs 100lbs. Plus, 600Ah of T-105 won't fit in the space.
Warren, do you have a link to the site you ordered the cells from?
 
Do you intend to top balance before assembly such as Overkill suggests?
No and Yes. I am going to assemble the pack, charge it, then break it apart and top balance. Top balancing 1200Ah of cells with a 10A supply would take a very very long time without charging first.

I now have it assembled and connected to the BMS, and the BMS is working. I'll start charging tomorrow, and probably top balance this weekend.
 
I built 2 100 amp batteries for my camper. I charged each cell to 3.65 volts individually with a 10 amp supply which went rather quickly and then assembled them into 2-four cell packs.
Can you share a single line diagram of your plan?
 
What I am doing is described here: https://diysolarforum.com/resources...-a-low-cost-benchtop-power-supply.65/download

It really the same thing you did, except I am pre-charging as an assembled battery instead of individual cells. My cells shipped 40-50% charged. So to charge them with a 10A supply would take 5-6 hours per cell, x 12 cells = 60-72 hours. Charging an assembled battery with a 20A charger will take between 6-7.5 hours.

Because I am only charging while I am able to sit and watch them, I can charge as an assembled pack in one sitting. 72 hours would take several sessions over a week or two.
 
I balanced all the cells yesterday. It took 12 hours to charge them to 3.6V. Then I put the battery back together and got it in place and hooked up. I finished after midnight. I still need to install a cover, and some of the battery cables are left from the previous owner and need to be replaced. But, it works!

I am now doing a capacity test, running my space heater though the inverter. It's drawing a bit over 70A, and my Victron SOC meter is estimating a 4 hour run time. The factory test data for the cells tested them at closer to 115Ah. So I expect to easily exceed the nominal 300Ah.

I now think it might have been possible to fit 4 6V batteries in there, but given the amount of work to relocating everything else in there, I think this was still cheaper. I have no Idea where I would otherwise mount that stuff. Clearly visible is my 3000W inverter and Victron solar controller. Not visible, hidden on the forward wall of the space is a 60A DCDC charger. On the port side wall are my negative buss and 2 shunts, on for the Victron and one for the Blue Seas meter, which I left in place. Not visible on the aft wall, in addition to the Victron, is a use block for "always on" circuits, and positive bus bars for each battery.


IMG_3784.jpg



IMG_3798.JPGScreenshot_20210311-073611_xiaoxiang.jpgIMG_3795.JPG
 

Attachments

Yes, I am working on updating drawings. Not a one line, but more compete drawings. I am also working on a long writeup of what I have learned and did. I don't have access to Autocad anymore, and am struggling with lesser software. :( I chose the 3kw because I got it used on a trade. It's on a 150W fuse, so it won't make that power.
 
No transfer switch. The inverter is a second "main" 2-pole breaker on my electrical panel, with a lockout so shore power and inverter power can't be on at the same time.
IMG_3800.JPG
 
Capacity test is done. 323Ah before my inverter shut down. It still had a little ways to go before the BMS shut down, but I decided to stop that test.IMG_3802.jpg
 
Warren,
What BMS did you use?
My 120A Overkill Solar had a total system failure.
Installed on an 8s 200amp 12 volt battery.
Did not do a load test. Too it out on the road for a 5 day camping trip. 3-days ok.
4th day everything started to bounce between4-6-8-13 volts. Fried my DVD player and refrigerator controller
Brought it back charged for a few hours, reinstalled and the same thing. Don't know what the MTBF is but this has not started out well.
The Bluetooth indicates most everything is ok. Temps went from 11 to 18 degrees during discharge but remained cool to the touch.
 
I am using the overkill. I did a load/capacity test at 70A-80A (current went up as battery ran down and voltage dropped)
That is a very odd mode of failure, and doesn't seem to me at first to be the BMS. FETs would normally fail open or closed, and I can't think of a way they would cut the voltage. And there are lots of them in parallel. For them all to fail in this odd way? To me it sounds like a loose or bad connection.

Overkill have a "whatever you do to break it we will replace it" warranty, and they have good support via email, although he is a bit busy and it took 24 hours for him to respond to my questions.

You can run without the BMS in a pinch. If the cells are well balanced and matched, just monitor the pack voltage to keep it within limits. If you have a good SoC meter you can set audible alarms at say 20% and 90% and have a wide safety margin.

I have been tweaking solar settings the past week. It currently charges to about 95% then drops directly to float, which is set to 13.4 volts. So, unless there is a pretty high load, it will cease charging until the next day. So I am ensuring the battery is cycling and not just getting to and staying at 100%
 

jose santin

Member
Warren, if you are using an inverter to apply the load then the Battery Voltage vs Current relationship you mention is normal. The power input vs. the power output of an inverter is given by Pin X Efficiency = Pout . So as the battery voltage of the input decreases the current of the input has to increase proportionately in order to maintain the same power. Power = Voltage x Current .
 
Warren, if you are using an inverter to apply the load then the Battery Voltage vs Current relationship you mention is normal. The power input vs. the power output of an inverter is given by Pin X Efficiency = Pout . So as the battery voltage of the input decreases the current of the input has to increase proportionately in order to maintain the same power. Power = Voltage x Current .
Yes, I understand that.
 
Top