A little scare with lithium

[Kelpie]

Had my first mishap with a lithium battery today. Not the DIY bank that I built and use to run all my domestic loads including cooking, which is a very safe LiFePO4 type.

It was a Ryobi power tool battery using cylindrical cells. I presume the chemistry is LiPo?

Anyway the problem was a shockingly bad design flaw. The clips which hold the battery in to the tool or charger have metal bands as springs, and these are separated from the cell terminals by a thin strip of foam rubber.

Today I was wrestling with the clips (they have always been very hard to squeeze in) and there was a click, and then suddenly everything got very hot and smoke started coming out.

As you can see in the photo, the metal spring had pushed through the (less than 1mm thick) foam rubber and made a short. So much current passed through that it actually burnt the spring and made it fall in two.



I think this is a very poor design, placing a piece of metal over two cell terminals with barely any insulation.
Secondly, I think it shows that whilst people (and insurance companies) get all hung about boats switching to lithium batteries, the real risk lies with more mundane things like power tools, laptops, and phones- all of which use much more dangerous chemistry, yet nobody thinks twice about bringing them onboard.

***INFORMATION UPDATE - PLEASE READ***

 

[Forty_Two]

Thanks for that heads up, I have a couple of those batteries on board

 

[jdc]

"It was a Ryobi power tool battery using cylindrical cells. I presume the chemistry is LiPo?"

It think it won't have been LiPo (Lithium Polymer), as these cells are almost always rectangular prisms, like mobile phone batteries, more likely they were Li-ion, which can deliver a very large currents so are a bit more dangerous. Not that it matters much!

 

[Kelpie]

"It was a Ryobi power tool battery using cylindrical cells. I presume the chemistry is LiPo?"

It think it won't have been LiPo (Lithium Polymer), as these cells are almost always rectangular prisms, like mobile phone batteries, more likely they were Li-ion, which can deliver a very large currents so are a bit more dangerous. Not that it matters much!

It's the way the battery is physically assembled that's the problem. They could have used plastic for the clip springs, or put something a bit beefier than foam rubber between them and the cell terminals. Accident waiting to happen.

 

[Graham_Wright]

Trading Standards?

 

[thinwater]

The interesting lesson here is that the real hazard on board is no a LiFePO4 main bank, but rather the many small lithium batteries we casually carry for other reasons. The fatal dive boat fire was caused by a small lithium/charger fire that started near the companionway, blocking the only means of access from below. Just this week there were two Li fires on passenger aircraft related to laptops.

For example, if you have the dinghy on the bow (covering the foredeck hatch) and a fire starts blocking your companionway ... you are cooked. Do you have sleeping cabins with a single means of egress that could be blocked? This is why appartments in a basement without a door are illegal in the US.

I guess the lesson is to store such things away from the companionway, and not deeply buried in a locker.

 

[Poey50]

The interesting lesson here is that the real hazard on board is no a LiFePO4 main bank, but rather the many small lithium batteries we casually carry for other reasons. The fatal dive boat fire was caused by a small lithium/charger fire that started near the companionway, blocking the only means of access from below. Just this week there were two Li fires on passenger aircraft related to laptops.

For example, if you have the dinghy on the bow (covering the foredeck hatch) and a fire starts blocking your companionway ... you are cooked. Do you have sleeping cabins with a single means of egress that could be blocked? This is why appartments in a basement without a door are illegal in the US.

I guess the lesson is to store such things away from the companionway, and not deeply buried in a locker.

The hazard mostly comes when charging. The rules on our boat are 1. never to leave the boat with a lithium battery on charge (except for our house LiFePO4) and 2. never cover a lithium battery on charge. I also have a few fireproof containers for charging li batteries like these from Amazon. They can be quickly picked up and chucked overboard if necessary.

https://www.amazon.co.uk/PsmGoods®-Battery-Fireproof-Protection-Charger/dp/B01FVW5XQC/ref=sxin_16_pa_sp_search_thematic_sspa?content-id=amzn1.sym.80aa8a4e-635c-4e2e-9a5d-c32f494cb6d7:amzn1.sym.80aa8a4e-635c-4e2e-9a5d-c32f494cb6d7&crid=RJQQP9IK5UMD&cv_ct_cx=lithium+battery+protective+pouch&keywords=lithium+battery+protective+pouch&pd_rd_i=B01FVW5XQC&pd_rd_r=2bdb5639-8894-41e4-a6f4-a5735b7a6d7a&pd_rd_w=ifIrB&pd_rd_wg=JbaI9&pf_rd_p=80aa8a4e-635c-4e2e-9a5d-c32f494cb6d7&pf_rd_r=XCW7CMWPP114435A4FET&qid=1678204866&sprefix=Lithium+battery+,aps,81&sr=1-2-ad3222ed-9545-4dc8-8dd8-6b2cb5278509-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9zZWFyY2hfdGhlbWF0aWM&psc=1

 

[j24jam]

Is that a genuine ryobi battery or a aftermarket one?

 

[fredrussell]

My friend’s shed burnt down when the genuine Makita battery left on charge went up. We also had a non-genuine Makita battery catch fire whilst charging on site a few years back.

 

[thinwater]

The hazard mostly comes when charging....

Yes, but the most recent aircraft fire with in an overhead bin, clearly not charging. We had a contractor job box burn up from a stored drill. I could go on and find many examples. Greater risk while charging, but not only risk. They can overheat if a failure allows rapid discharge, such as the OP's example.

Not "the sky is falling." Just throw the thing in the water. Just a smart storage warning. These things are going to be with us from now on, in increasing numbers, and not all will be well-manufactured, and some will have hidden mechanical damamge. Such is the life of devices and tools.

 

[justanothersailboat]

Crikey! that's awful. I have some of these, I will be opening them up now and checking their condition.
Those are almost certainly lithium ion 18650 cells exactly the same as in many lithium ion boat battery projects... ebikes... and all sorts. Not li pos.
However they are definitely a lot more dangerous when there are a lot more of them wired together, so the more mundane things are to some level made a bit safer by just not being very big. Concern about big packs is still justified. Imagine that short with 10 or 100 times the amps behind it and a higher voltage too.

 

[gregcope]

exactly the same as in many lithium ion boat battery projects...

i have not seen any boat 18650 used in boat battery projects. Got any links?

i have seen someone on youtube recycle 000’s of these for what i think is a 48V 5Kwh domestic shed battery

 

[justanothersailboat]

i have not seen any boat 18650 used in boat battery projects. Got any links?

Not on hand to be honest, sorry. I don't save them, I think it's an impression I have picked up from dubious Youtube types rather than the sober folk of boat forums. And I've met the occasional over-keen li-ion refurbisher in person in the past. Shall dig some links out in the morning if I can sieve them out of the internet soup. The lithium iron phosphate projects are a different ballgame, stabler stuff, much more sensible. Really high energy batteries are still a bit fearsome regardless of chemistry though. I've done a bit of battery rebuilding, enough to make me very cautious.

Providing there is sufficient space around it I am much happier with shed batteries than boat ones, since you can sometimes walk away from a shed.

 

[Neeves]

These things are going to be with us from now on, in increasing numbers, and not all will be well-manufactured, and some will have hidden mechanical damamge. Such is the life of devices and tools.

Well said

Almost every small rechargeable device we own now will be lithium based. Often the battery is hidden, sometimes hidden in a 'pack' and we will not know the integrity of the pack unless we break it open (which will destroy its integrity).

Many items are professionally made by companies with good QC (Ryobi) - but that actually does not seem to make much difference to the risks.

People will be complacent. Fires will become increasingly common .

Jonathan

edit

Can you actually have a fireproof box on a boat? I envisage isolating all the batteries in a box, maybe some on recharge - if one goes they all go......or do you have multiple boxes (seems unrealistic in practice). We all use recharge torches, phones, power banks, strobe lights (for LJs), angle grinder (in case mast comes down) etc etc

It looks like an excellent project for Practical Sailor and PBO - not me - outside my comfort zone.....

J

 

[William_H]

i have not seen any boat 18650 used in boat battery projects. Got any links?

i have seen someone on youtube recycle 000’s of these for what i think is a 48V 5Kwh domestic shed battery

I have moved to replacing the battery on my little boat with a pack of 12x 18650 cells and a charge controller. So 3 cells in series gives 11.7 volts with 4 sets in parallel . About 8 AH Gives enough power to run 25w radio and LED nav lights plus phone charge, for enough hours. (I have not actually run it down yet.) So small I just take it home for recharge. Charge controller something like this. 3S 20A Li-Ion Lithium Battery 18650 Charger BMS Protection 12.6V For Drill Motor | eBay Can be chareged from a 12v battery on charge (13.8v.)
Note however that this controller will not deliver enough current on discharge for 25w radio so Schotky diode used to bypass discharge for full current.
Note also there are some terrible 18650 cells available from China. Avoid Ultrafire.
For Oz people these are the best value 18650 I have found. Solar Magic 2200mAh Lithium Ion Rechargeable Batteries - 2 Pack

 

[thinwater]

Well said

Almost every small rechargeable device we own now will be lithium based. Often the battery is hidden, sometimes hidden in a 'pack' and we will not know the integrity of the pack unless we break it open (which will destroy its integrity).

Many items are professionally made by companies with good QC (Ryobi) - but that actually does not seem to make much difference to the risks.

People will be complacent. Fires will become increasingly common .

Jonathan

edit

Can you actually have a fireproof box on a boat? I envisage isolating all the batteries in a box, maybe some on recharge - if one goes they all go......or do you have multiple boxes (seems unrealistic in practice). We all use recharge torches, phones, power banks, strobe lights (for LJs), angle grinder (in case mast comes down) etc etc

It looks like an excellent project for Practical Sailor and PBO - not me - outside my comfort zone.....

J

[Read your back PS issues--it's in there!]

Perhaps the simplest answer is a metal tool box. It will slow any fire down, and there is a handle to grab. Once upon a time, power tools came in steel boxes. I'm dating myself!

 

[Neeves]

[Read your back PS issues--it's in there!]

Perhaps the simplest answer is a metal tool box. It will slow any fire down, and there is a handle to grab. Once upon a time, power tools came in steel boxes. I'm dating myself!

Knuckle rap accepted - no excuses.

Just another plug for PS

Ensuring a Safe Space for Batteries - Practical Sailor

Tool boxes were always steel ammunition boxes, always green -you are just a youngster.

Jonathan

 

[Neeves]

I shudder at the title of this thread - I'd hate to read a thread on a big scare.

Jonathan

 

[justanothersailboat]

"Avoid Ultrafire" - they really call batteries that? I suppose customers can't say they weren't warned...

 

[Birdseye]

all of which use much more dangerous chemistry, yet nobody thinks twice about bringing them onboard.

Are they really more dangerous. How often do you hear of someones phone catching fire? No doubt there is a case somewhere but the lack of multiple reports suggest that there is little risk. I did once try to get a LiFe battery to ignite both with a dead short and water immersion but failed miserably.

Interestingly I came across a boat whose engine had moved in heavy seas off Gijon in Spain with the sump flange cutting the main battery cable and causing a dead short . Luckily they were still able to switch off the main battery switch but not before the huge current flow had burnt all the insulation off the battery cables and burned through the top of two of the three batteries exposing plates and acid plus setting fire to woodwork. So the risk is not just a dead short of a lithium iron battery but also of the conventional lead acid. The key to the latter is a fuse in the main supply..