Are Lithium Ion Batteries Safe?

[92 Nitro 190dc Owner]

I have 5 lead-acid batteries on my boat, one for starting, 3 for the trolling motor, and one for electronics. As you may imagine, that is quite a bit of weight (approx. 250 pounds). I have been seriously considering switching to lithium ion batteries. I've been researching lithium ion batteries and find a number of fires are caused by lithium ion batteries and not sure if I should switch. Here is a good description I found of what happens: Lithium is a highly reactive alkaline metal. This makes it ideal for storing large amounts of energy in battery form, but also makes it potentially explosive when something goes wrong. The key is in the construction of the cells which make up the battery. When in use, electrons flow between the cathode and the anode through a perforated separator. If this membrane breaks down, either through poor manufacture, old age or mishandling, a short circuit can occur. Then the cell quickly heats up, the electrolyte expands and a toxic, flammable gas is vented, sometimes explosively. In bigger batteries with multiple cells, the heat starts to damage neighboring cells, which then also malfunction. This process is called thermal runaway and, once triggered, it is very hard to stop. When the cell is breached, highly reactive lithium simply adds fuel to the fire. Based on what I've found in my research, I'm going to hold off for awhile and wait for more data to come through about this issue. Hopefully, the price will come down as well. Has anyone on this forum experienced an onboard fire resulting from lithium ion batteries? I want to be sure I'm not being overly cautious.

 

[Andrebass]

I like your thinking,

Lithium batteries have been around for a while, but now they are used for larger application than the handy dandy drill motors.

I think more research and trial and errors need to be done to ensure safety over weight.

 

[Wayne P.]

Depends on which chemistry is involved. Lithium Iron Phosphate (LiFePO4) batteries are safe. That is what is used for boats/electronics

 

[Tim_C]

Lithium ion batteries are not the same as the LiFePO4 (Lithium iron phosphate) batteries used for trolling motors. Lithium ION batt is not safe for most marine use. IONs are the type that are causing the EV car fires, and computer battery fires on airplanes. LiFePo batteries have a BMS (battery maintenace system) which is a control board that prevents over charging and runaway output.

 

[Wayne P.]

https://etekware.com/types-of-lithium-ion-batteries/

 

[Andrebass]

Thanks for clarifying
I learned something today

 

[92 Nitro 190dc Owner]

Thanks for the explanation! I didn't realize that there were different chemistries involved. This eases my mind. Thanks again!

 

[Starbanker]

Lithium ion batteries are not the same as the LiFePO4 (Lithium iron phosphate) batteries used for trolling motors. Lithium ION batt is not safe for most marine use. IONs are the type that are causing the EV car fires, and computer battery fires on airplanes. LiFePo batteries have a BMS (battery maintenace system) which is a control board that prevents over charging and runaway output.

I just learned another important fact today, LiPo battery BMS is a big problem with alternators. The bigger the alternator the worse it gets, if you use LiPo alone as a starter battery. LiPo batteries can charge very quickly and don't have a problem with high output charging, however when they are full the BMS kicks the battery off the alternator power. When that happens the alternator overloads and burns out the diodes (one-way electronic devices that prevent feedback current) in the alternator (They have a built-in amperage tapering off circuit, but they cannot instantly handle a no-load scenario). There are devices that prevent that, but they are expensive and are another link in the chain that could fail. Mercury alternators aren't even listed as suitable for the cut-off switches. I'm glad I didn't buy that LiPo battery package for my boat when I ordered it, besides saving myself $1400.00 by buying four LiPo from amazon and keeping my four lead-acid that came with the boat. I still use the AGM for the starter, have three LiPo for trolling and one for electronics I do have a switch to use the electronics battery to jump start if I need it and switch it off the Merc when I don't. I doubt if I'll ever start the motor with it connected, I'll just switch it on to charge the starter battery for a short time then switch it off before starting the motor. I didn't get the very expensive Platinum extended warranty that includes electrical items from Mercury.

 

[CincyGus]

I bought 4 Ionic (Lifepo4) batteries in my new Targa V19 and had them wire them while they were prepping my boat, along with a Minn Kota 460PCL charger. 3-50ah for my 36v Garmin Force Trolling motor an a 125ah house battery that everything but my engine is running off off. I keep the one group 27 AGM battery as my starting battery but have my 125 wired to a A, B, A+B switch, OFF that I can use to jump the starter if I ever need to. Due to hurting my back 2 days prior to picking up my boat in May, having Fusion surgery (L4-L5) mid August and recovering and building back strength since, I only got my boat on the water last week for the first time. Put about 20 hours on the big motor and completed breaking in and used the trolling motor for about 2 hours as I couldn't take too much casting musky lures yet so most of it was trolling. Love the quick charge, love the bluetooth app to check strength or issues with each battery. I bought Ionic because of the great reviews on their customer service (American's that you can talk too) along with the features of their BMS. The weight reduction and smaller footprint of the batteries was another huge factor. Twice the power of a group 27 in a smaller and 1/3 the weight battery made it nice for this old guy.

 

[Starbanker]

I wouldn’t jump the AGM, just add enough charge to get the engine to turn over. Switching also causes a no-amp condition that could cause the alternator diodes to burn up. Also, the starter needs about 200 amps instantly, most BMS’s are limited to about the total AH’s. My 100 AH batteries are limited to 100 amps before it switches them off I carry one of those battery/capacitor jump starters just in case. I already had someone who needed to jump their jet-ski. Much better than carrying cables, no messy snagging, all fits in a case the size of a carton of cigarettes. I was very impressed by how many starts that thing had in it. I’m putting my boat away for winter and I’m glad those lithiums only weigh 25 lbs a piece. Taking batteries out the tight compartment is quite a task for old guys like me.