lipo misinformation

[sailr]

When lipos first hit the scene a few years back, they were not very stable. The old horror stories, even then, were remote. They were the result of misunderstanding of the care and feeding of lipos and overamping, overcharging, overdischarging, etc. There has been tremendous improvement in the composition and quality control of the packs in the past two years.

In general, those of us using lipos have paid attention and become much more educated regarding their use. I started using lipos in 2003-2004 and have NEVER had an incident. BUT...I charge them right and use them right.

For what it's worth, I have seen nimh packs blow up also!

[egneg]

I have only had 1 pack puff and I bought the pair used so their back ground is questionable at best.

[SJFE]

I have seen nimh packs blow up also

I have had Ni cells pop... The IB4200s where just plain junk toward the end. Now the 3600s they where damn fines cells









Man this picture brings me back....

[domwilson]

Now that lipos have proven themselves in this hobby, it's just a matter of brand, "C" rating, mah rating, etc. There is, of course, a lot of misinformation out there. Especially with recommendations.

[FloatDaBoat]

Actually salt water behaves exactly like a resistor does by creating a short between the pack leads. It may take a long or short time to discharge a pack depending on the salinity of the water. Distilled water is a non-conductor and will never discharge anything. But then we don't run in distilled water, much of the surface water in the US is filled with various ions which will help to dischage a submerged pack over time.


.

I performed a little resistance test on H2O. I taped two steel washers ~ 3/8” (0.375” or 9.53 millimeters) apart on the bottom of an old Gladware plastic food container. I then proceeded to make the following measurements with my $20 digital multimeter with the test probes attached to the washers, which were covered by:
4 ounces of supermarket distilled water - 112.4 K Ohms
4 ounces of tap water - 5.15 K Ohms
4 ounces of tap water with 1 teaspoon of table salt stirred in - 1,169 Ohms (1.169 K)
Not very scientific; it should suffice to compare conductivity between the three.

[tsenecal]

myself and several of other members of the subcommittee (yes its real, check it out http://subcommittee.com ) run our submarines with Lipos in the wet, for several hours at a time.

water by itself won't kill a healthy Lipo.

[Gary]

Well at least he changed the picture! Andy.........you are my hero!!!!!!!!!!!!!!!!!!!!!!!! LOL

[FloatDaBoat]

I have had Ni cells pop...

Anything like these ???

[domwilson]

I had a Nimh burn up like that.

[Flying Scotsman]

The point is use the manufacturer's instructions on all facets..charging..storage..disposal etc.
If you follow those guidelines, you will not have a problem. If the battery gets wet, it is corrosion on the tabs that will cause problems. There have been many silly stories on battery powered equipment. The other sources of power are probably more dangerous gas/petrol. nuclear,etc. and Andy's avatars.

Douggie

[domwilson]

The point is use the manufacturer's instructions on all facets..charging..storage..disposal etc.
If you follow those guidelines, you will not have a problem. If the battery gets wet, it is corrosion on the tabs that will cause problems. There have been many silly stories on battery powered equipment. The other sources of power are probably more dangerous gas/petrol. nuclear,etc. and Andy's avatars.

Douggie

And do your research. See if others have had problems with the brand you are looking to purchase.

[astecme]

Modern Lipo's are fine if you obey the charge/discharge rules. Water will corrode the internal connections so it is advisable to sela the packs with silicon.

With old packs they used to "explode" well a big flame. Lithium is flamable but there is so little of it in modern lipo's it should not be a concern. With modern lipos you can drive a nail through the pack and you will only get a small fizz.

Lipo's are more stable than NIMH cells which vent hydrogen when abused!

[Steven Vaccaro]

All I have to say is just because it hasn't happened to you, doesn't mean it isnt true.

All sources of stored energy are dangerous. Try to store more then fits and boom.

[Doby]

With modern lipos you can drive a nail through the pack and you will only get a small fizz.

Wrong

[sailr]

Please don't talk about how safe they are these days and that you can drive a nail through them! I think you are confusing lipos with the LiFE (lithium iron) batteries such as A123's. These are NOT lipos! They also don't have as much capacity, are big and heavy, etc.

Modern Lipo's are fine if you obey the charge/discharge rules. Water will corrode the internal connections so it is advisable to sela the packs with silicon.

With old packs they used to "explode" well a big flame. Lithium is flamable but there is so little of it in modern lipo's it should not be a concern. With modern lipos you can drive a nail through the pack and you will only get a small fizz.

Lipo's are more stable than NIMH cells which vent hydrogen when abused!