Lithium Battery Failures??

[ShoreFun]

I did a bit of poking around and could not find anything.

I have always been the repair guy for stuff. I am new to sailing with a little Hunter 170. I have dealt with a lot of different repairs of electronic stuff. I have seen a lot of odd problems from weather and corrosion. This is across a wide variety of devices. I work with aircraft and aircraft ground systems, but I also help my brother with car stuff and people bring me a lot of different stuff to see if I can resurrect it.

I read about people doing conversions to the lithium batteries. What I am curious about is the failure of the batteries. Please do not take this as a I do not like them. I am just curious at this point about some issues. It is in my nature to ask questions and sometimes this gets me in trouble. Clearly these batteries are a great thing.

So a normal lead acid battery is pretty simple. While you can cook them electrical problems resulting in the batteries being at least partially unusable is pretty hard.

These Lithium batteries use a dedicated internal charge control system. They also have a bunch of connections internally that may suffer from corrosion. One picture showed normal crimp connectors I know will have issues in wet environments.

So I see two issues both leading to a failure of providing any power.

First is something disrupting the electronics. From an odd back feed like a motor that is not wired right to close lightining strikes. Close strikes are a problem as they set up a high voltage field that can cause failures of electronics some time after they occure.

Second is if the batteries are not built to marine electronics grade with all the corrosion precautions, well you can have funny problems as connections slowly go to a high resistance. I am thinking that the case may be fully sealed making this a none issue.

Thanks!

[senormechanico]

Lots of links here.
Do a search for lithium, house banks, etc.

[john61ct]

Originally Posted by ShoreFun

These Lithium batteries use a dedicated internal charge control system

Wut?

Some might, none that I would use.

Yet anyway.

Look at systems from Lithionics or Victron for best of breed implementations, maybe MasterVolt, Redarc in Australia?

It is a whole system, and the BMS is ideally external and modular.

The cells themselves are usually milspec indestructible, other than charging while frozen, or allowing out of spec currents / voltages. Should be jacketed with metal plates to keep their shape.

Of course the infrastructure for marine use must be designed and built appropriately.


And protection of any sensitive electronics is required just as with comms / nav gear.

Nothing particular to the chemistry of the cells though.

[SaltyMetals]

So my question is how safe are the Li batteries, whether they be Li ion or Li metal batteries? I am not referring to the house or engine batteries but all that other stuff that we collect on our boats for the batteries to power drills, sanders, polishers as well as scooters, bicycles, drones and battery powered safety gear. Are we introducing onboard an accident waiting to happen, whether we are on board at the time or get back to our boat to find nothing but a charred wreck?

Li batteries have truly transformed battery driven items being so light & compact and holding so much charge at the same time but....... ?

Andrew

[Delfin]

Originally Posted by SaltyMetals

So my question is how safe are the Li batteries, whether they be Li ion or Li metal batteries? I am not referring to the house or engine batteries but all that other stuff that we collect on our boats for the batteries to power drills, sanders, polishers as well as scooters, bicycles, drones and battery powered safety gear. Are we introducing onboard an accident waiting to happen, whether we are on board at the time or get back to our boat to find nothing but a charred wreck?

Li batteries have truly transformed battery driven items being so light & compact and holding so much charge at the same time but....... ?

Andrew

I think you'll find that LiFePO4 batteries are as safe, or perhaps safer than lead acid batteries. 2 years or so into using my LFP bank and I can't detect any heat even during .33 C charging.

[john61ct]

Yes LFP are a completely different category than all the other more risky lithium chemistries.

Toss and replace the latter soon as you see they're getting warm, start to swell etc, they are a consumable, only last a few hundred cycles.

There are proper care protocols, sophisticated chargers and load testers etc available for any type, but more of a hobbyist out in the back shed thing, easy to burn down your living space.

None of which applies to LFP.