Sturmhauptfuhrer

I guess it is something I may have to experiment with I guess. A member or two at the club uses them (5000 Mah lipo's) and doesn't seem to have any issues with them. I've been educated though through this conversation that there ARE many risks and potential hazards to using them. I guess I'll have to do the math, figure out what my TRUE power draw will be, and do the calculations to see what would be best for the situations. I'm thinking though that the 10,000Mah lipo is a bit over kill as I don't think I could use it al up in a day just playing around with my tank and even having battles all day. That's a lot of juice to try to drain down. lol

I can honestly say though that there is a split division between the two types of batteries as far as the opinions go, guess I'm going to play with these ideas and weight them out with the opinions given and like I said I'm going to experiment a bit to come up with the right system. A low voltage ESC or votage cut off with alarm is definitely going to be part of that system along with a GOOD lipo balancing charger and charging lipo bag!! :-)

Imex-Erik

I'm glad you are taking it seriously. As stated by a few, there are pros and cons. If used safely they can be a big help, but if not they can be a huge problem. Make sure to get a balance charger and read up on batteries. Most lipos dont like to be charged at more than 1C (some though are now saying 2C-3C charges are ok, I still stick with 1C) and most connectors should be changed immediately (deans male sided plugs, though most of the time aren't on the batteries, can pose a threat to a charger as they will be open connections waiting to short something) and correct storage is a must.
Spend a few extra dollars and get a name brand battery and a lipo bag. I cannot stress how important a lipo bag is. GET ONE. Then find somewhere safe to charge like your garage floor. Make a metal enclosure that holds your batteries/chargers and keep it away from anything flammable. Of course get the correct fire extinguisher for lithium. Something as simple as a metal toolbox will work for a quick evacuation plan out of your house. Also, something not noted by others yet... buy a fire alarm and attach it near your charger. Make sure and get the most annoying one, this small device might save your house
Here are a few pictures of my work charging box (the small one for my desk) with a 10A charger, my batteries to test for the day, my LVA's, a 2-3 cell checker, and some more nimh chargers kinda hidden. It is crappy I know, but remember this is just an evacuation box. When smoke happens or anything at all, you disconnect your power and throw it outside! The top tray still comes off so you can save the other batteries.

Edit: 10,000mAh is overkill. A 4000mAh battery gets me almost a full day of demos at a show, 10k should get you at least 4 hours of solid play. That is a long time to tank...

ausf

That's a nice set up and a good point on the connectors. The four that have gone up on me in the past three years were all connector related. Three damaged (not visibly) from hard landing/crashes and one faulty. The faulty one was on a 2 cell 850 mAh around midnight in my shop on the third floor. As it arced and started to puff, I had to decide whether to throw it out the window and hope I cleared the deck or try to contain it, since there was no way I was going to try to run through the house with it. Luckily I was a foot away from a pair of snips and cut the wires then sealed it in a metal box and got it outside and it didn't flame up.

This was not during charging or use, I just disconnected it from my Xion Kettenkrad and put in on the bench. A minute or so later, it was on it's way to puff city, next stop flamesville. I guess that makes me an absolutely unique moron since I wasn't even touching this totally safe battery. Imagine it that was an hour later when I was in bed or in the back of my car driving home from the field?

Metal toolboxes are great and a must.

Imex-Erik

Thanks for the comments! Yea a metal box is almost necessary for safety. I got a nice 70's era toolbox donated by our mailroom lady. I just drilled the rivets out, flattened it, cut the top off, and made a hole in the side for wires. Works great and free, cant beat that.
The connectors are always kinda iffy with me. I know people like deans connectors, but I hate them. I run a lot of DC current to stuff and when I have a 22pc octopus cable hanging around it only takes just a bit to brush against open connectors. I prefer adapters that are recessed. EC5 and Andersons are quite nice.
That is strange you lost a battery like that, I still treat mine like glass. Even with all this said, I still think lipos are a good choice. As you see, that is just my charging que for the day, tomorrow will be different Treat your toys well and they will reward you. I still have to find a way to hook that 6 cell up to a tank... maybe the tank I found upstairs will work....

PatternFlyer

My Feedback: (182)

I just got the HL Leopard 2. Looked through and checked the manual.
On the back where parts are listed. It shows 7.4V lipo 2600mAh as an option. Nothing mentioned about if the board is compatible with Lipo.
Better contact Heng Long. the NiCD pack it came with (1700mAh), only cycled to 750mAh. A few more cycles and if it doesn't improve, I will throw it away.


I would like to add a few more things about LiPo beside what Erik said.

Try to get a charger that has "Lipo Storage" charge/discharge function. It is critical for longer LiPo life span.
If you want to keep the battery long (more than a couple of years), do not discharge anymore than 80% of the capacity, always keep the battery charged at least 50% capacity to around 65% (storage mode).

If you don't plan on running the tank within 24 hours, do not keep the battery fully charged.

Some of Lipo packs that I have are from 2005/6 15C packs. They still work (not as strong as what it state) on light loading.

I use various size from 30mAh to 5000mAh ranging from 1S to 10S and up to 70C rated packs. All my packs are in storage mode unless I plan on flying within the next 24 hours or less.

YHR

I use the recessed XT6O connectors, There isn't any bare metal showing on these. God forbid if a guy ever stuck a Deans male ends on a LIpo battery. That would be an accident waiting for a place to happen.

The case for a Lipo is strong. I have one tank all FPV'd up and it really demands power as it is a metal Sherman and is heavy. So far I have been making due with the NIMH, but I did have to add a separate battery supply to the receiver to prevent brownouts. A Lipo would probably look after all of this, but as most have indicated, these batteries can be hazadous if not handled correctly. .

Sturmhauptfuhrer

Hey,

Last night I was surfing the net for Lipo batteries and balancing chargers and I came across this charger from Venom. Also their batteries weren't to badly priced I didn't think for a named brand anyway. This is a duel charger, and even though I really don't need the I-pod speaker player part of it really, it does have it's own power source and all the features that I believe it should have, though I still may be wrong. They (Venom) also has a contained charging box as well that I thought was pretty cool too.









I also found this battery cutoff protector That I guess goes in line between the receiver and the controller I'm thinking........perhaps?? At any rate, I will insure that I, my family, the house, and the tank are well protected when messing around with the wonderful world of Lipo batteries. Research, Research, Research!!

http://www.venom-group.com/Medion-Ch...upply-Kit.html

FreakyDude

Just read this thread and the comment below scares the jeepers out of me. Trust me folks you do not want to arc a Lipo battery nor bash it, hit it or drop it. You want to make sure you run it with an alarm and you want to make sure you know what your doing before using Lipo batteries for anything. All the stories you hear may not be true but a vast portion of them are. I seen a lipo almost kill a guy once on a jobsite, He was using a drill, it arc'd and poof instant roman candle.
City hunter I highly doubt you arc'd a lipo and nothing happened unless it was very low in voltage, from what you say below you gotta be the luckiest person around.
Lipo's have their points but those points have NO value in a tank and in fact you not only risk fire and all the known lipo hazards but you also risk voiding any kind of warranty or goodwill with your electronics. Somebody running a Lipo also runs the risk of frying their electronics, The boards are not built to take the amps lipos can push.

philipat

So, in a similar vein...what about Li-Ion batteries? Specifically, the LiFePO4 batteries? I've seen a few articles on them and their proponents seem to say that they have the advantages of LiPos without the safety issues (ie, durability of NiMHs). Has anyone tried these yet? If so, where did you get them? I've done a quick search and can't find much for RC cars (which generally work in the tanks).

Imex-Erik

Here is a small read on LiFe batteries: http://www.flyelectric.ukgateway.net/lithium-a123.htm
This page is a bit dated as now you can find a few different capacities of LiFe batteries, but the overview is correct. Most chargers now have LiFe settings, so making an adapter is pretty obsolete. I do still recommend balance charging, but personally I dont have too much experience in the LiFe area yet. I plan on power testing them soon. You can run them in your tanks now but you must have a low voltage alarm capable of alarming at 2.5V-2.7V to get the best performance.

Once again I am extremely interested in getting some LiFe batteries to test. Safer lithium batteries?? Count me in.
Also, please note Li-ion and LiFe batteries are different compositions

Tanque

These are are what I mentioned on the first page of this thread.

http://www.a123energy.com/lithium-ir...te-battery.htm

Jerry

philipat

How so? I thought they were the same thing.

Have you used them? Experiences?

vonmarshall

My Feedback: (1)

I did not realise you could run Lipo's through a Tamiya DMD/MFU... can somebody confirm this is OK before I go and kill my tank!?

Green Amphibian

I have been running 2S Li-PO's in my Tamyia tanks for 4 years with no problems.

Herman

vonmarshall

My Feedback: (1)

That is great news... many thanks

Imex-Erik

I guess I should of said "LiFe is a different type of Li-ion than you are used to," as most Li-ions we know (cell phones and such) are 4.1V max (lithium colbalt oxide aka LiCoO2) LiCoO2 has a nominal voltage of 3.6V and a max of 4.1V. LiFe (aka LiFePO4) has a nominal voltage of about 3.2-3.3V and a max charge of 3.6V.
Here are some more links for you about LiFePO4 batteries:
http://en.wikipedia.org/wiki/Lithium...sphate_battery
http://www-scf.usc.edu/~rzhao/LFP_study.pdf (really good overview of pros and cons of different types of li-ion batteries)
http://batteryuniversity.com/learn/a...of_lithium_ion (battery encyclopedia)

I'm still new to them as well but it looks like I might actually be ordering some for my quadcopter soon. I just need to check out my KKboard and see if I can run one.

Jeff489

My Feedback: (12)

Lipo and Life batteries have been discussed many times on RCU, mostly (and aptly so) in the "Batteries & Chargers" forum.

Over the years, they've also been discussed specifically in regard to RC tank applications.

http://www.rcuniverse.com/forum/rc-t...batteries.html

http://www.rcuniverse.com/forum/rc-t...batteries.html

http://www.rcuniverse.com/forum/rc-t...l#post11016253

http://www.rcuniverse.com/forum/rc-t...batteries.html

ausf

I know some AC guys who swear by the A123s in their planes. These are huge expensive fuel type, but they use the A123s for servos and Rxs.

CountChocula

Does anyone know if alarm/cutoff is needed if using LiPo's with Clark boards? From what I hear, Tamiya's cutoff automatically at a certain voltage.

Thx,

Dave

Merganser

I have to use lipos on my quads so I started out charging outside in the barbeque. Two years ago I picked up a tabletop barbeque on seasons end clearance for $7.00. I added a piece of broken patio brick as a platform for extra safety. Any thoughts on that kind of a setup? I also store the lipos in a metal ammo can. jot

Imex-Erik

Man that is a GREAT idea. I would think a bbq would be the best place to set fire right? Prolly not a good idea to cook marshmallows or steak over it though

Tanque

I would think it would be ok as long as you don't completely seal the can tight. If memory serves when you close and lock the lid on an ammo can it's
airtight no? It a battery decides to go off I wouldn't want to be there...

As a open topped storage container it should work. I would image though if a burning battery generated enough heat if the can was sitting
on something flammable that might be a problem.

Jerry

ausf

The barbeque is where all mine go to wait for disposal. I transport them in the metal tins you find everywhere as packaging, but these are the tiny one cell 150-350 mAhs you'd use in UM foam planes. Not big enough to cause too much trouble, but definitely good enough to burn a digit or two. My biggest concern with them is if the kids left one out that our Lab pup could get to. A tiny blowtorch in his mouth, however brief, can't be too good for him.

The Low voltage alarms are to protect the battery itself or as cutoffs in planes/helis to let you know before it drops from the sky. Usually around 3.3 v per cell. Even the cheapest ones have it, cutting out the motor intermittently before the drain becomes too severe. I think someone mentioned Tamiya cutting off at 6v, which would mean the battery is toast.

Jeff489

My Feedback: (12)

Not true. I run 2s LiFePo4 (3.3v per cell) batteries in my Tamiya tanks, and often run them inadvertently until the DMD cuts out for low voltage. I've had no damage to tank or batteries in 4 years. I don't know the actual voltage that triggers the DMD cut out, but I do know that it does so before I get battery damage.

The only thing that kills my batteries is leaving the tank on by mistake (which seems to happen more than one might think). A full power drain kills my LiFePo4 batteries; however, I find that if I let the discharged battery sit for a couple days, I can recharge it about 1 out of 4 times. So...a full drain is not always fatal to the battery.

MAUS45

Jeff, are you using something like this LiFepo from Hobbieco LiFeSource.....Found it at Tower Hobbies....

http://www3.towerhobbies.com/cgi-bin...&I=LXDVCD&P=ML

They have them in 1100mAh, 1300mAh, 1800mAh, 2100mAh, and 3200mAh.