Lithium Iron Phosphate batteries: Are they safe?

[Winston29]

I'm only half serious.  I've heard the stories of them blowing up or catching fire, so I have to ask.  In my boat, a WindRider-16, the battery sits directly behind me, just under the rear deck.  

Right now I use a single, 55 Amp/Hr AGM battery to run my Minn Kota Riptide-45 trolling motor, but it weighs a ton and, along with my 225# of meat and bone, pushes the stern down more than I'd like.  It also doesn't give me a lot of run time, given the max Amp draw on the motor is 42A.  

The 100 Amp/Hr LifeP04, lithium iron phosphate battery would just about double my run time, and it only weighs 25lbs, but I'm a little worried about having it sit 6" behind my butt.  

Should I be worried, or are the fire risks only when charging it?    

 

[gbkersey]

The LiFePO4 batteries are the safest type of Lithium batteries as they will not overheat, and even if punctured they will not catch on fire. The cathode material in LiFePO4 batteries is not hazardous, and so poses no negative health hazards or environmental hazards.
 

 

[Zonker]

Don't forget a AGM battery shouldn't be discharged to 0% if you want to keep them alive.

So a 100 A.hr Li Ion has more than 2x the USEFUL capacity. Don't know if you flattened the AGM though, so maybe only 2x 

 

[Monkey]

I just ordered a 100 ah Relion to handle my instruments/running lights. If you can get past the hit on the wallet, lithium phosphates are no brainers. 

 

[solosailor]

 I've heard the stories of them blowing up or catching fire, so I have to ask. 

You heard wrong.   They can overheat and even melt down but do not catch fire.   Blowing up, nope.   There are plenty of dangerous chemistries that can.

 

[Monkey]

You heard wrong.   They can overheat and even melt down but do not catch fire.   Blowing up, nope.   There are plenty of dangerous chemistries that can.

It’s a common misunderstanding. LiPo’s are dangerous little fuckers, but good at what they do. They also account for 99.99% of people’s concerns when they hear “lithium” mentioned in a battery. 

 

[Max Rockatansky]

It’s a common misunderstanding. LiMH are dangerous little fuckers, but good at what they do. They also account for 99.99% of people’s concerns when they hear “lithium” mentioned in a battery. 

Fixed it for you. Ferrous phosphate safe, mmkay?

 

[Winston29]

Cool, thanks for all the helpful replies!  I went ahead and ordered one, but I cheaped out and went with the $400 model on Amazon.  

https://www.amazon.com/gp/product/B084DB36KW/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

I know, I know, Chinese batteries are junk, but I just couldn't justify putting the $900+ Relion in a boat worth less than that.  83% of the 957 Amazon reviews were 5-Stars, and many of them were from people who used it for my intended purpose.    

I'll be putting it in a box to make sure it doesn't get dunked in salt water, and I have a NOCO Genius-5 that's said to be sufficient to keep it charged.  

Hopefully I'm good to go.  If not, I'll buy the Relion RB100 and chock it up to another one of my expensive lessons learned the hard way..  

 

[slug zitski]

I'm only half serious.  I've heard the stories of them blowing up or catching fire, so I have to ask.  In my boat, a WindRider-16, the battery sits directly behind me, just under the rear deck.  

Right now I use a single, 55 Amp/Hr AGM battery to run my Minn Kota Riptide-45 trolling motor, but it weighs a ton and, along with my 225# of meat and bone, pushes the stern down more than I'd like.  It also doesn't give me a lot of run time, given the max Amp draw on the motor is 42A.  

The 100 Amp/Hr LifeP04, lithium iron phosphate battery would just about double my run time, and it only weighs 25lbs, but I'm a little worried about having it sit 6" behind my butt.  

Should I be worried, or are the fire risks only when charging it?    

View attachment 466287

Safe ? just ask the guy who owned this boat 

 

[Max Rockatansky]

Make sure you have a BMS for your batts that disconnects, not just gives warning… and you could keep the Relion after the boat is gone, you know

FYI, another fairly inexpensive option is this guy, and I know Jim via the local harbor:

https://lithiummarinebattery.com

FWIW, I’m in my fourth year full time live aboard with 400Ah of LFP

 

[Monkey]

Cool, thanks for all the helpful replies!  I went ahead and ordered one, but I cheaped out and went with the $400 model on Amazon.  

https://www.amazon.com/gp/product/B084DB36KW/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

I know, I know, Chinese batteries are junk, but I just couldn't justify putting the $900+ Relion in a boat worth less than that.  83% of the 957 Amazon reviews were 5-Stars, and many of them were from people who used it for my intended purpose.    

I'll be putting it in a box to make sure it doesn't get dunked in salt water, and I have a NOCO Genius-5 that's said to be sufficient to keep it charged.  

Hopefully I'm good to go.  If not, I'll buy the Relion RB100 and chock it up to another one of my expensive lessons learned the hard way..  

View attachment 466307

I fully understand not spending that kind of money. (Employee discount for the win!) I wasn’t recommending any particular brand, I just went with that one because the BMS is built in and because the price was right. 

 

[Monkey]

Fixed it for you. Ferrous phosphate safe, mmkay?

Not sure what you’re correcting. I said LiPo. Lithium polymer. Not safe, mmkay?

 

[SimonGH]

Safe ? just ask the guy who owned this boat 

What are the details behind the pictures?

Was that actually the battery going into thermal runaway?  Was it a LiFePO4 chemistry battery?

There are so many variables in the cause of a fire.  But inherently the chemistry in LiFePo4 does not experience thermal runaway.

However according the ABYC the DC system on any boat is the leading cause of fires.

 

[slug zitski]

What are the details behind the pictures?

Was that actually the battery going into thermal runaway?  Was it a LiFePO4 chemistry battery?

There are so many variables in the cause of a fire.  But inherently the chemistry in LiFePo4 does not experience thermal runaway.

However according the ABYC the DC system on any boat is the leading cause of fires.

Don’t know 

they “say “ lithium batteries 

fire department couldn’t extinguish the fire 

 It was in the water at the time 

 

[IStream]

Another classic low-information/N=1 post.

LiFePo with a BMS (internal or external) that can cut the battery off from loads and charging sources is pretty damned reliable and safe. Your propane system and the remainder of your electrical system are a greater threat.

 

[SimonGH]

the devil's in the details...

A Li-ion battery in thermal runaway is a scary thing.  I've literally seen them melt their way out of aircraft.

But that's a completely different chemistry than LiFePo4

 

[Leeroy Jenkins]

If you went from FLA to LiFePo4 on a cruising boat would you need to rethink solar controllers and shore powered chargers?  Alternators?   

 

[slug zitski]

If you went from FLA to LiFePo4 on a cruising boat would you need to rethink solar controllers and shore powered chargers?  Alternators?   

if it’s a modern boat you may be able to reuse some components

Typically every component must be upgraded 

also the battery cables , lithium is capable of absorbing very high amps  

 

[IStream]

if it’s a modern boat you may be able to reuse some components

Typically every component must be upgraded 

also the battery cables , lithium is capable of absorbing very high amps  

This is BS. You need to change your charging profiles and not float the batteries at 100% SOC but charger upgrades are optional. If your battery cables are sized appropriately for your current FLA batteries and chargers, they'll work fine for those same chargers with LFP. 

LFP batteries typically charge at up to C/2, so if you've got a 400Ah house bank, you can charge it at 200A. However, if you've only got a 100A charger, it'll work just fine. You won't be taking full advantage of the batteries' fast charging capabilities but there's no harm done. Likewise, because LFP can accept that C/2 charge for most of its recharge cycle, your alternator may taper its output due to heat but as long as its got good thermal protection, there's no harm done.