Lithium Ion Battery DIY

[stockrex]

I bought some Samsung Li NMC cells to build a 12v Li battery for my boat/van

The prismatic cells are in a bmw battery in a 3S config,

1. BMS - I can't find a BMS with bluetooth, it would be nice to have bluetooth

Anyone have any experience in DIY LiFE battery build, care to share dos/don'ts pls

 

[fsdork]

If you have time, find some related videos on Will Prowse's YouTube channel. He has several relating to BMS. I don't recall specifically if he had discussed any with Bluetooth.

 

[ragtoplvr]

Lithium batteries have about 1/3 the energy density to Dynamite. You do not want to discover that on your own.
Normally these only have battery balance, a way to disconnect high current is expensive. I have never seen a bluetooth enabled balance board.

Rod

 

[stockrex]

True, I am comfy with the battery.
30 A is the most my system will have a draw,
Circuit breaker are the best inline to disconnect currents, and they are cheap.

I lack the knowledge on smart monitoring solutions, I did watch a bunch of diy stuff, seems DALY makes good BMSs for charging with user inputable max/min voltage

I wonder if DALY has a bluetooth version of their BMS.

 

[PandaBear]

Is the LiFE cells 3.3 V or so, are you planning to step up the voltage to 12V to power your car / charge it? What do you plan to do with voltage surge or cold crank? Do you have any estimate what kind of inverter or charger you will need?

I don't think this is a good idea to build a setup before you can answer those questions first.

 

[BeerCan]

What cells are you using exactly? You say NMC in one part and LiFe in another. They are different batteries.

I think I was going to do a 3s setup I would use electrodacus. Unfortunately it's not BT enabled but does have WiFi. For the 4s and 8s stuff I do I get the BMS from overkill solar. They have bluetooth.

Types of Lithium-ion Batteries – Battery University

Become familiar with the many different types of lithium-ion batteries: Lithium Cobalt Oxide, Lithium Manganese Oxide, Lithium Iron Phosphate and more.

batteryuniversity.com

 

[thastinger]

You'll want 4S for a vehicle. The regular vehicle charging system will charge it fine as will a digital battery charger. The BMS is only needed when balancing.

 

[stockrex]

NMC - I cancelled my order, they are OFF my list,

I read an article about an explosion in AZ with these batteries, yikes.
Li NMC are unstable and explody

LTO - This is top on my list but I am not able to find used batteries at decent prices. New are bit too $$$ for my budget.

LiFePO4 - This is an option now.

Yes, for LiFePO4 - 4S would be the 12V build.

BMS - DALY has a series of smart BMS with BT option,

I never used one and I have to look into further for the following features:

1. User settable max charge voltage
2. User settle min voltage for cut off

Use:
1. The Battery pack will be used for a power source for my trolling motor, electric fishing reels and sonar in my boat.
2. In my Van - with an inverter to drive my microwave and CPAP etc

I plan on building 2 x 12 V

Thoughts on LiFePO4 cell's stability?

My concerns are temperatures in MI
we are in 40s most of the year and in summer 90s,

 

[BeerCan]

I only use LiFe in my builds. More stable than most of the others. If I need balancing I use the BMS from overkill solar. If I don't need balancing I use a victron charger. Both are bluetooth and both are programmable.

 

[JHZR2]

You know they sell 12V LFP batteries these days, right? K2 makes and markets them.

You’re asking for a battery fire. Good project for a learning experience, but there’s lots to get right.

I don’t fully understand your use profile. Is this intended to be a starting battery? Will it float on the 12v alternator bus? Will it be in parallel with a 12v lead battery?

 

[stockrex]

Use-
Sorry, I will try to clarify.

My boat has a small starting battery and the outboard produces 35A max. I am not sure of the output profile but 10A max would be a safe bet for recharging the batteries.
My fishing style is mostly trolling at 1.5 to 2 mph for hours on.

Van - to power the inverter for coffee or warming food,
My van has 60 A 12 V source which I could use to recharge the batteries.

These batteries are NOT going to be used for starting. These are strictly "House" batteries, *stand alone*

I am tired of maintaining Flooded batteries and having limited range. with 2 100 AH house batteries in the boat, I am down to 85% after a year of use storage and then charging them is tedious due, as they have to be charged often, plus they are heavy.

12v LiFePO4 - > Trolling motor
12v LiFePO4 - > Inverter - > microwave

Charging-
1. No solar
2. I will use my honda 1000w genset either at the launch or at my storage space for the boat.

I agree, lots of avenues to make mistake. Hence the questions.

I might end up getting an off the shelf batt.

-----------------
BMS - Thanks I will look into the overkill, solar, looks like they have the features I am seeking.

Charging - Definitely charge via BMS, I need to figure out a 12V power source which has enough output Amps

 

[meep]

I flew RC helicopters for a few years, all using lithium batteries. This is a high-stress application where the batteries are exposed to unprotected loads, no under voltage protection, high current, high vibration and (yes, sigh) occassional “high impacts.” In addition, charge strategy is up to the hobbyist to decide upon.

this experience is what has slowed my interest in BEVs. We will surely one day have one, but I’ll feel better if they don’t charge in the garage. If they do (they will...) there WILL be a smoke alarm in the garage, wired into the home.

lithiums hold a bunch of power, even replacing a worn iPhone battery demonstrates how much if it merely bends because the manufacture’s adhesive doesn’t let go like it’s supposed to (does he speak from experience?) and the battery shorts internally while being wrestled out. It happens quickly, and you can’t really stop It once the reaction starts (honey, please open the window first and ask questions after as I carry this smoking battery on your dinner plate to throw it out onto the driveway...) (not really but close, the window was already prepared since I knew it could be a thing). The best thing I did was regular physical inspection... as they would show delamination and hotter running temps before getting critical. I was ok with them because of physical inspection.

it’s a known hazard with the RC community that these things will burn down your home if not respected. I always charged mine on a fireproof plate, away from flammable materials, and only when I was home. I wouldn’t throw them on the charger and leave. Disposing of failing cells in a salt water bath before chucking in the trash was also interesting, though I didn’t understand what I was looking at.

they hold so much power in them for their size! for this sort of purpose, were I to build a lithium pack with some sort of BMS, I’d want to intentionally test and observe it over many (manies) cycles, conditions, temperatures, before becoming comfortable with it operating in an out-of-sight manner.

ive been looking at one of these for a little tinkering, and still go through the same mental checklist

"Dayton Audio LBB-5 5 x 26650 Lithium Battery Charger Board / Module" from www.parts-express.com!

Dayton Audio LBB-5 5 x 26650 Lithium Battery Charger Board / Module

www.parts-express.com

be safe!

 

[BeerCan]

No real worries with lithium if you stick to LiFe. They are a lot more stable.

What I don't get is why you want the hassle of a diy battery/BMS if you are going to be portable. I would get some lion energy lithium or similar with a victron programmable charger and be done with it. A little more expensive but much easier to move around.

Costco often has the lion batteries for sale on their website for great prices, you just need to keep watching for them 699 usually. BMS is built in and it's like a group 27 size.

If you weren't using it as a trolling motor I would suggest a bluetti or titan setup.

Lion Safari UT 1300 - Lion Energy

Lion Energy is offering a limited lifetime warranty on the 12V, 105Ah Lithium Iron Phosphate Lion Safari 1300 battery. This will be the last battery you'll ever buy. Order online today!

lionenergy.com

Blue Smart IP65 Charger (120V and 230V) - Victron Energy

The Blue Smart IP65 Charger is the new professional battery charger with built-in bluetooth. Find a Victron Energy dealer near you.

www.victronenergy.com

 

[BeerCan]

Not to beat a dead horse but I wanted to show you some pictures from my DIY builds. They get very messy and have lot's of exposed wires and dongles. I use them only when the batteries are going to remain in one place because there are many wires. You have to solder or mechanically attach wires to every cell in your battery for the BMS to work. It can turn into a spaghetti mess real quick. Not saying it can't be done nice and neat and enclosed etc, etc. Just saying sometimes kiss is the way to go. This is 24v stuff but it looks the same, also the victron charger pictured is 12A so it is a little larger that the one I linked.

the wires in my hand need to be attached to each individual cell

Bluetooth is usually a dongle and not integrated

The victron is so much more compact and clean if all you need is programmable charging. (on the left)

Here are some shots of the current cells I am using, you would need 4 of these. Of course these are 280aH so they are fairly large, but you would need a way to hold 4 cells together. They can't be to tight because the grow and shrink, stationary it's fine but in mobile applications it's a pita.

 

[meep]

That’s quite impressive... and you’ve got a lot going on there. I’m not as current (haha) as you are with the latest battery tech. With your experience, you probably can achieve more confidence than I in building something stable, reliable and safe. Nice work!

 

[Cujet]

I have a 1974 Honda XL100 with a 6V system out at the airport (gets occasional use) . The 6V lead acid batteries last about 1 month, and then it's impossible to get the thing to start. This is due to very poor voltage regulation (even with new components) that boils the battery dry, the small 6V battery and and the low chinese quality.

So like the post above, I went LifePO4. I simply purchased a 6V LiFe battery from Amazon and installed it. The claim was that the battery had it's own current limiting and cell balancing circuit. The battery was a replacement for a kid's toy car, and is limited to 10A discharge. Which the motorcycle headlight, taillight and ignition system easily exceeds when the engine is not running.... triggering the protection circuitry.

However, 6 months down the road, the battery still works, and the bike will start if I turn the headlight off. I'm not at all sure the battery is the right solution, but it's better than constantly purchasing chinese 6V lead acid batteries.

Amazon.com: TalentCell 6V 6Ah LiFePO4 Battery Pack LF060A1, 2000 Cycles Rechargeable Lithium Iron Phosphate Battery with Charger : Health & Household

Amazon.com: TalentCell 6V 6Ah LiFePO4 Battery Pack LF060A1, 2000 Cycles Rechargeable Lithium Iron Phosphate Battery with Charger : Health & Household

www.amazon.com

 

[stockrex]

Beer - 280Ah, you are speaking my language,
I looked them up and they are priced very well too.
Exactly what I need for cells.

Can you provide some background on the DC power sources in bottom pic pls?

Mat list:
1. LiFEPO4 Cells - 280Ah - 8 of them
2. BMS - 2 x12 BALY smart in series for 24V? I need to research if DALY can be connected in Series.
3. 5A - Battery top balancer

Pending - Input needed:
1. reasonable battery capacity tester

Heating mats
1. I am adding heating mats to my cells, I need to figure out the design if it is possible for the BMS to trigger the heating mats. For heat, I think motorbike handle heating mats probably will work.

-----------------------

280Ah LiFEPO4 cells
1. 4 of these will fit in a 31d battery space, my boat has space for 2 31ds so I will be able access 560 Ah, let say at 80% draw down and 90% max charge I will have 392Ah
my trolling motor has as max draw of 50A at max speed
That will give me 8 hours of trolling at max speed, wow, I mean wow.


New PROBLEM:
Charging the batteries back 400AH at 20A will take many days, lol,

Any suggestions on how to charge em faster?

 

[stockrex]

I have a 1974 Honda XL100 with a 6V system out at the airport (gets occasional use) . The 6V lead acid batteries last about 1 month, and then it's impossible to get the thing to start. This is due to very poor voltage regulation (even with new components) that boils the battery dry, the small 6V battery and and the low chinese quality.

So like the post above, I went LifePO4. I simply purchased a 6V LiFe battery from Amazon and installed it. The claim was that the battery had it's own current limiting and cell balancing circuit. The battery was a replacement for a kid's toy car, and is limited to 10A discharge. Which the motorcycle headlight, taillight and ignition system easily exceeds when the engine is not running.... triggering the protection circuitry.

However, 6 months down the road, the battery still works, and the bike will start if I turn the headlight off. I'm not at all sure the battery is the right solution, but it's better than constantly purchasing chinese 6V lead acid batteries.

Amazon.com: TalentCell 6V 6Ah LiFePO4 Battery Pack LF060A1, 2000 Cycles Rechargeable Lithium Iron Phosphate Battery with Charger : Health & Household

Amazon.com: TalentCell 6V 6Ah LiFePO4 Battery Pack LF060A1, 2000 Cycles Rechargeable Lithium Iron Phosphate Battery with Charger : Health & Household

www.amazon.com

Cujet, the built in bms/charge controller is awesome IMHO, one can buy these modules for few dollars on amazon. Thanks for sharing your experience,
My previous experience with LI-ION batts in m power tools have been HORRIBLE, due to the bms cutting of charging as some cells discharged more than others.

I am taking a stab at LiFEPO4 batts, next if I find used LTO batts I will pick up a few for the boat and not have to worry about cold temps.

 

[BeerCan]

Beer - 280Ah, you are speaking my language,
I looked them up and they are priced very well too.
Exactly what I need for cells.

Can you provide some background on the DC power sources in bottom pic pls?

Mat list:
1. LiFEPO4 Cells - 280Ah - 8 of them
2. BMS - 2 x12 BALY smart in series for 24V? I need to research if DALY can be connected in Series.
3. 5A - Battery top balancer

Pending - Input needed:
1. reasonable battery capacity tester

Heating mats
1. I am adding heating mats to my cells, I need to figure out the design if it is possible for the BMS to trigger the heating mats. For heat, I think motorbike handle heating mats probably will work.

-----------------------

280Ah LiFEPO4 cells
1. 4 of these will fit in a 31d battery space, my boat has space for 2 31ds so I will be able access 560 Ah, let say at 80% draw down and 90% max charge I will have 392Ah
my trolling motor has as max draw of 50A at max speed
That will give me 8 hours of trolling at max speed, wow, I mean wow.


New PROBLEM:
Charging the batteries back 400AH at 20A will take many days, lol,

Any suggestions on how to charge em faster?

I charge mine with solar. That has a whole bunch more considerations and costs to factor in and probably outside of your scope. I would look on ebay for a high amperage bench power supply. You can get the switching style for relatively good prices, no need to go linear IMO for battery charging. However if you do it this way you need to watch and adjust the PS so as to not cook your batteries. Or you could spend more and get a programmable PS and adjust it that way.

The two items in my picture are
top the riden bench PS, very cheap and good but it would take you years to charge a bigger 12v battery
bottom my Amrel DC load bank.


As for balancing, unless you are going to really geek out on the batteries I would not put to much effort into it. Let the BMS do its thing, but even if you used a straight up charger you can find everything you need to know with a cheap multimeter and if you had to balance individual cells with a PS.

As for the battery tester you need to define more of what your goals are. My DC load bank was 1k used and I got a great deal, carbon pile (good/bad) testers are $49.

This is the type of testing I do, this was a repurposed A123 battery from a car pack

Here is the latest spec sheet on the 280aH batteries in case you are interested

 

[stockrex]

Beer, thanks for sharing the details, a lot to digest here.
I am still all over for charging solution. I am going to peek at ebay for 12v power source

Solar charging, awesome, what panels are you using? I just enquired with my city about ground solar panel code stipulation. They said none.

Some source of DC voltage/high current --> MMPT controller ---> LIFEPO4 [direct/via bms]

I think 50A at 12v will be adequate charging for me 4 hours or charging will put back 200 AH, that will be around 8 plus hours of trolling in my boat, I never fished that long yet ;-)

Update -
1. 8x280AH LiFEPO4 cell bought from Alibaba
here is the link

This product is no longer available.

This product is no longer available.

www.alibaba.com

sea freight was $199

2. Now I need a BMS
I see they have common port and separate port.
Go with separate port?