lithium batteries

[jetjr]

LiPO require specialized charging and discharging. As said cannot be overdischarged , even once can end them. They can produce very good current and do so at full requirement until they reach minimum volts and this is the problem, theres no warning they are going flat until too late.

 

I think all LiPO have the posibility for thermal runaway too, some even whilst stored but Im sure they are more stable than they used to be. In RC they are supposed to be charged and stored in flame proof bags. Wouldnt be impossible to build a bag to house battery for Jab full time?

 

Seeing as Jabiru charging arrangement is quite 'agricultural' Im not sure this would be OK to simply put one in.

 

 

[Gibbo]

LiFePO4 is really good at going boom! Lithum is one of the most reactive metals so personally I would stay away from anything containing it.

 

Apple recalled a heap of iPods because of a similar type of battery that liked to get a little warm in the pocket.

 

 

[Bruce Tuncks]

Thanks guys for the good comments.

 

I haven't been able to find stuff to indicate a safety problem with LiFePO4 but I may have missed it. There is a real problem with lithium polymer, I know from first-hand experience.

 

I didn't know about the Antigravity batteries, but they do look better packaged than the Hobbyking ones. But I am getting these Hobbyking batteries for another purpose anyway.

 

When the Hobbyking 8400 4s2p arrive, I'm going to try them to see if they will start the Jabiru.

 

If they do, then the charging problem will need looking at. For example, the picture of the batteries shows a balancing connector, and I can well believe that the Jabiru voltage regulator ( I have the original one) may not be right. If Mark sees this, he may tell us about his charging setup on his plane.

 

Bruce

 

 

[turboplanner]

Bruce, before you try to start the Jab and maybe have a problem, I'd suggest emailing the Manufacturer to see whether the battery has cranking ability. shouldn't take long and they'll know. I wouldn't want to put one of these batteries under too much amperage stress.

 

 

[Tex]

Hi Bruce, TP, Amperage stress is something LiPo doesn't mind, until you get low on voltage!! Each cell has a small voltage range 3-4.3v with in which they will not suffer damage. The C rating is the useful time of delivery. If this battery delivers at 30C, that is delivering all its useful current capacity until discharge @ 30 x 8.4 Amps (16 with the two of them) 1C = 1 to 1: so one hour. 30C is 2 minutes.

 

The small lead is for balance charging... as the cells are all linked in parallel and series, just driving current into the output to charge is not the best way to do it because the cells do not receive a clean flow to suit each requirement (higher or lower charge) Balance charging ensures the each cell is topped up in a balanced way compared to the others. Balance charging is not always required but it is definitely needed with regularity.... always if possible. I do not know how the Anti Gravity mob have gotten around this but suspect, it is in the box.

 

I have the 12cell on my 582 but think I need to go up one size.

 

Yes LiPo are dangerous, but if managed properly they are like the fuel in your tanks. Damage to the pack is bad. Those ones... if they are going bad with out a damaged case will get puffy first. You know they are done if they do that and need to be safely discharged and disposed of.

 

 

[Bruce Tuncks]

Hi Guys, I tried the hobbyking batteries out yesterday on the ground. I used two LiFePO4 packs of 13.2 volt , 8.4 amp-hour in parallel to give 16.8 amp-hour. Well they turned the 2200 motor over a bit faster than the Odyssey, (which did a good job) and they showed a cranking voltage of a bit over 11 volts. So there was no shortage of capacity to do the job.

 

Now there are the issues of charging and safety to look into. If these can be resolved, I'll start using them. The pair of batteries are much lighter than the Odyssey.

 

... Bruce

 

 

[dazza 38]

I dunno what batteries they use in those electronic cigarettes.But one blew up in a blokes mouth in Florida (Bigpond news) smashed some teeth apparently.

 

 

[eightyknots]

I dunno what batteries they use in those electronic cigarettes.But one blew up in a blokes mouth in Florida (Bigpond news) smashed some teeth apparently.

This is yesterday's news item about this tragedy (you have to feel sorry for the user!):

 

Electronic cigarette blows up in man's mouth

 

 

by Chris Matyszczyk February 16, 2012 4:10 PM PST

 

A Florida man is taken to hospital after an electronic cigarette explodes while he is smoking it. He loses his front teeth and has burns. Fire officials say the battery seems to have been the culprit.

 

 

What some e-cigarettes look like. There is no suggestion this type was the one involved in the explosion.

 

(Credit: Screenshot: Chris Matyszczyk/CNET)

 

From the age of dot, we're all told not to put gadgets in our mouths.

 

But along came electric toothbrushes--and then electronic cigarettes. Some will wonder how safe they might be after a 57-year-old Florida man was taken to hospital Monday night when his electronic smoke exploded while he was smoking it.

 

He ended up in an Alabama hospital, facing burns, the loss of part of his tongue and his front teeth.

 

Joseph Parker, division chief for the North Bay Fire Department, offered a graphic analogy to the Associated Press: "It was trying to hold a bottle rocket in your mouth when it went off. The battery flew out of the tube and set the closet on fire."

 

I feel sure that the "Jackass" people must have tried something along these lines, but how horrific that it should happen to someone who, by all accounts, was merely desperate to give up smoking.

 

The physical damage from the explosion--it apparently happened in the man's home office--comprised burned carpets and even smoldering pictures. The brand of cigarette hasn't been disclosed.

 

Read more: http://news.cnet.com/8301-17852_3-57379648-71/electronic-cigarette-blows-up-in-mans-mouth/#ixzz1mbtTrXXg

 

 

[Bruce Tuncks]

Dazza and eighty, if these were not Lithium-Iron-Phosphate batteries then your postings were plain dopey.

 

Please check your facts and try to stay with the plot.

 

..Bruce

 

 

[dazza 38]

Dazza and eighty, if these were not Lithium-Iron-Phosphate batteries then your postings were plain dopey.Please check your facts and try to stay with the plot.

..Bruce

WTF, Most use Lithium - Ion Batteries FWIW. Anyway, other people have mentioned different types of batteries in posts above mine. Besides why dont Jabiru get their sh!t together so people like you dont have to stuff around trying different batteries etc.

Bruce - Its lithium-ion, not lithium-Iron BTW

 

 

[eightyknots]

Dazza and eighty, if these were not Lithium-Iron-Phosphate batteries then your postings were plain dopey.Please check your facts and try to stay with the plot.

..Bruce

Hello Bruce, the batteries used by electronic cigarettes are Lithium Ion. They are rated at 3.6 volts for two reasons: one is the physical size limitation to enable it to fit inside something resembling a cigarette and the second reason is so that the battery may be rechared from a standard USB outlet. Of course, I recognise that it would be completely impossible to start your Jabiru with this battery. The capacity (i.e. cranking current) and voltage would be incorrect.

 

However, the makeup of the battery has similar properties to the larger 12 volt batteries. For instance, the LiFe PO4 mentioned in post No 31 above, still uses lithium ion technology similar to the battery that exploded in the electronic cigarette.

 

 

[PapaFox]

Its lithium-ion, not lithium-Iron BTW

Lithium-ion and lithium-iron are different batteries. Lithium-iron are a type of lithium-ion battery, but the cathode is made of LiFePO4, hence the new sub-type of iron. The lithium ions that form the electrolyte, depending on manufacturer, can both be the same lithium-perchlorate liquid. Confusing details, but significant none the less.

 

 

[turboplanner]

http://www.kennedyalternativeenergy.com/lifepo4.html

 

This link claims that LiFePO4 batteries are less prone to Thermal Runaway.

 

Note that it is an unsubstantiated claim, and note that it does not say thermal runaway will not occur.

 

It would be reckless to get into an aircraft with this information because of the potential rapidity of the fire.

 

What's needed are definitive tests from a recognised institution. Given that thermal runaway is the safety issue holding back car designers, I wouldn't think that information would be long coming IF these batteries were immune from thermal runaway.

 

 

[geoffreywh]

Nasa think so too.........................Quote "NASA finds LiFePO4 batteries are safe and reliable enough for multi-year missions in extreme environments encountered by automated robotic lander"

 

 

[eightyknots]

Lithium-ion and lithium-iron are different batteries. Lithium-iron are a type of lithium-ion battery, but the cathode is made of LiFePO4, hence the new sub-type of iron. The lithium ions that form the electrolyte, depending on manufacturer, can both be the same lithium-perchlorate liquid. Confusing details, but significant none the less.

Saying "Lithium-ion and lithium-iron are different batteries" is similar to saying "petroleum products and petrol are different fuels. The reality is that Lithium-Iron batteries ARE lithium ion batteries (but there are other lithium ion batteries too). This is what wikipedia says:

 

The LiFePO4 battery uses a lithium-ion-derived chemistry and shares many advantages and disadvantages with other Lithium-ion battery chemistries.

 

 

[Guest Andys@coffs]

To use an analogy, petrol and avtur are both petrolium based products. Common sense dictates that you should not have an open flame around either.....but if you do....make sure you choose the avtur "experiment" if you dont want to appear in the darwins awards.

 

LiFePO4 is the equivalent of Avtur, the other lithium ion chemistires which are more energy dense than LiFePO4 such as laptop and smartphone batteries are the petrol equivalents. Bottom line is that the balance of energy density vs safety is more desirable. We could use LiFePO4 in those consumer goods but the battery will be bigger and weigh more or have a shorter life, something the average uneducated user is entirely unwilling to accept given that a smartphone is generally good for one day only of business use......We think we've gone forward and back when the nokia6310 ruled the roost it was good for the better part of a week......albeit without facebook and twitter....What cabbage agreed to trade battery life for that cr@p!!!

 

Andy

 

 

[Bruce Tuncks]

Does anybody know what type of battery is used in the new power-tools? You can't get much else in Bunnings now and they seem to be getting rid of the last Ni-Cad tools.

 

I've not heard of them being dangerous, and there must be many thousands of them out there now , some getting misused for sure.

 

Anyway, as I said earlier the Hobbyking LiFePO4 (2 of 8400mah) batteries started my 2.2 Jab really well, but I'm not going to fly with them until the safety and charging issues are sorted out.And I agree with eightyknots to the extent that we need to be cautious here.

 

... Bruce

 

 

[fly_tornado]

I wouldn't worry about the fire issue too much, the usual life of a LiFePO4 battery is very heavy discharging and rapid charging. fuse it up properly and install an isolation switch if you are worried. I would make sure you ground charge it properly after every flight.

 

 

[Bruce Tuncks]

Here's the latest in the lithium story.

 

I installed a 4s LiFePO4 battery-protection board from All-Batteries.com . After working out that the 1500 watt starter-motor should draw 136 amps at 11 volts, I reckoned that one of the batteries rated at 252 amps should be ok. This was confirmed by 60 sec of cranking with the mags off.

 

Now that I've flown the plane, I reckon that the nearly 6kg of weight saving makes the take-off better, but of course I would think that. Anyway, lighter is safer, especially for short-field work.

 

I appreciate the cautionary comments that have been made, but my assessment is that the risk of a fire during flight is low. The fire I have personally seen with a model plane Li-Po

 

battery was at max amps, and max amps with the Jabiru is of course on the ground when cranking. This is when thermal runaway would happen if it does at all.

 

I'll report back in a few months to tell how it works over time.

 

Bruce

 

 

[Old Koreelah]

Thanks for that, Bruce. Been following this story, but missed the weight of your battery and the size of Jab engine.

 

 

[Kyle Communications]

I gather Bruce you are using the 2 packs in parallel....that's a lot of grunt for 2 kg of weight.... How about the alternator charging the batteries?

 

They are out of stock at the moment I want to use them for my cpap machine when away on flying trips

 

 

[Bruce Tuncks]

I did buy 2 packs and tested them out in parallel. This gave me a scare because the engine belted over so hard I worried about burning out the starter-motor.

 

So now I am only using one pack and it still belts over. This makes the weight 1 kg plus the battery-box. The cranking voltage is 11 volts with the single lithium pack as opposed to 9 volts with the Odyssey.

 

The lithium obviously has a lot less internal resistance.

 

One of these packs would make a good booster setup if you have trouble starting on frosty mornings. Is that what a cpap is?

 

... Bruce

 

 

[damkia]

One of these packs would make a good booster setup if you have trouble starting on frosty mornings. Is that what a cpap is?

... Bruce

CPAP (Continuous Positive Airway Pressure) is to stop sleep apnoea. Sleep apnoea is the cessation of breathing due to obstruction of the airways while you are asleep and completely relaxed. A partial form of the same thing is snoring - taken to the extreme is apnoea.

CPAP provides a small baseline continuous pressure to the airways, keeping them open so that breathing can still occur, via a mask which is usually placed over the nose or nose and mouth connected to a machine while you sleep.

 

 

 

[boingk]

Awesome to hear someone has done the Lithium route conversion, I love the things and am installing them in my motorcycles when I get a chance... ie dead battery strikes.

 

The packs I'd be using are also the HobbyKing 8.4Ah 4s LiFePO4 jobs, can't beat the price and the performance sure is something, too. I regularly use their cells in my RC aeroplanes and have good faith in them so long as the max load isn't exceeded - I puffed a few LiPo's early on playing that game and now just use larger/higher rated cells.

 

The 'Burst' rating supplied is generally given by the manufacturer as the maximum sustained output from the pack for a short period of time, usually around 10~15 seconds or so. I tend to take it as the current you can run your packs at if you want them to... burst! :D

 

Cheers - boingk

 

 

[mlpinaus]

I hesitate a little to write this..... I ordered my (2010) j230 with the Anderson connector on the cowl. This to allow jump starting in the field. I used this as designed on a cold morning at Horsham once. Worked well. Then it struck me... what to do if there is no 12v source? In short I purchased a LITHIUM ION GO KART BATTERY YT7B4 (YT7B-BS) 130CCA from the batteryman who advertises on ebay. This battery weighs less than 1 kilo and is the physical size of a normal alarm gel battery. The Anderson plugs are available from Jaycar along with suitable high current wiring. Got a good charger from Fleabay . The high cranking current is real. The thing just spins the jab motor..... Store it in a steel cabinet most of the time,

 

regards

 

Marcus