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Mid-Sized Lithium Batteries: A Warning

Mid-sized Lithium Batteries

There have been some written warnings about various sizes of lithium batteries onboard, and I have a longer one in draft, but there is an immediate need to talk about the middle-sized lithium batteries onboard.

Overall, small lithium batteries in your phone or laptop are generally reasonably safe, although they can flare up when physically damaged. That is why airlines want a flight attendant there if you are digging out a phone wedged in your seat mechanism…. damage is a big fire risk.

Similarly, large lithium house battery installations are well-protected from runaway fires and have a different chemistry from the smaller batteries. Warning, they can be harmed if charging systems and batteries do not come from the same manufacturer. 

The biggest issue is with mid-sized batteries and charging.  Think the battery on an e-bike, e-scooters, or potentially even an electric outboard.  The New York City Fire Department counts over 200 e-bike and e-scooter lithium fires per year, primarily when batteries have been damaged and/or are being charged.  Findings by them include: heightened risks when batteries are not charged by the proper charger, but instead by a similar or an aftermarket charger; and fires occurring when no one is watching or nearby the charging apparatus.  (see a recent PSA by NYCFD at ).

What should sailors do:

1.  For e-bike, e-scooter and outboard-sized batteries, always have someone observing the charging of mid-sized batteries.  Do not charge them while asleep or off the boat.  Also, always have the batteries in sight, not buried at the bottom of a locker. 

2.  Be very cautious with any mid-sized lithium batteries greater than 160 watt-hours: don’t let them get damaged by other gear, or get wet, especially with salt water. See NYCFD PSA on damaged batteries at ).  If they are physically damaged, toss them overboard.

3.  Charging many batteries on boat circuits not designed for those loads can cause issues at the charger level and may cause fires. Again, be smart and sensible.

4.  Stan Honey recommends having welder’s gloves nearby when charging mid-sized lithium batteries.  With them, you can grab the battery and throw it overboard - the only real way to rid yourself of the fire risk.  

5.  Think twice before loading that e-bike or e-scooter aboard the boat.  While they appear very handy, you must make sure they are dry, safe from harm, and can be charged safely.  Be wary.