Li Ion Battery Safety Shutdown
Created by Sherlock on 2024-02-10
Li Ion Battery Safety Shutdown
Most batteries/cells get warm when they are charging.
When LiIon batteries get warm they maybe overcharging and getting ready to explode. An exploding Li Ion cell is like an Estes Rocket Motor, very hard to handle and extinguish.
Here is a simple way to stop over-charging your batteries. It uses an inexpensive temperature controller available on eBay. There are several available. Bayite TCF-3A017 (https://www.ebay.com/itm/173557719280).
This controller cuts the charging power off when it reaches a set point. I have mine set for +80F. I put the heat sensor on the battery case when charging. If +80F is reached the controller turns the charging power off.
This is a Fail-Safe battery charging protection system, your battery charger should be able to shut down the charging all by itself when it is completed. If it fails or if you have a shorted cell this controller will shut it down.
It is best to monitor your LiIon cell/battery charging and to keep it away from any flammable materials, (outside of your house).
Sherlock
| AD0AR | 2024-02-17 | |
|---|---|---|
| Re: Li Ion Battery Safety Shutdown | ||
| 100% LIFEPO4 for the WIN! I got my first big ones from Temgot.com and I have not looked back! Bluetooth with a onboard built in color display! Reply to a comment by : G4AON on 2024-02-12 Better still, don't use lithium ion batteries. Lithium iron phosphate (LiFePO4) are less likely to burst into flames and a pack is around 12.8V, so more useful around the shack or for portable use with "12V" radios. | ||
| K4VBX | 2024-02-14 | |
|---|---|---|
| Li Ion Battery Safety Shutdown | ||
| This is well thought out and designed, I would hesitate to call the system "fail-safe." 80dF cut off is conservative. But what about Li-ion that isn't kept at room temperature (summer use, non-air conditioned space)? For a damaged cell, there is no safe cutoff voltage. You're right they can be "like an Estes Rocket Motor," when they begin to fail. Compromised Li-ion cells are just as risky in an "idle" state as they are when charging. Even careful battery pack construction, though, doesn't address the hazard. The danger is the multiple unknowns. Unknown defects in manufacturing, unknown when failure will occur, unknown when/if an out-gassing cell will combust, unknown if that combustion process will happen like a flare, rocket-motor or flash bang. I think the hazard mitigation also requires safe, isolated (but not sealed) storage and keeping Li-ion batteries small. Need more than 24V or 5Ah? Strongly consider alternate chemistries, such as LiFePo4, which are well-suited to radio use. | ||
| KL7JT | 2024-02-12 | |
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| Li Ion Battery Safety Shutdown | ||
| Second AON's comment re LiFePO4. Use a known good BMS and charge in an open or very well vented, stout metal or glass container. Best to avoid LiPoly cells. They cause many of the problems we hear of. They are cheaper, but IMNSHO somewhat like carrying gasoline (petrol) in an open paper container. | ||
| G4AON | 2024-02-12 | |
|---|---|---|
| Li Ion Battery Safety Shutdown | ||
| Better still, don't use lithium ion batteries. Lithium iron phosphate (LiFePO4) are less likely to burst into flames and a pack is around 12.8V, so more useful around the shack or for portable use with "12V" radios. | ||
