Lipo Battery Question

[IceChilly]

Just browsing on Towerhobbies while placing an order I saw this battery pack

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXVDB7&P=7

I was wondering if this would be ok for a tekin fx-r with tekin 45t crawling motor in my CR-01 I have building.

I have a few coupon codes so Im trying to max out my savings along with the "easy pay" option will make it easier on my wallet at the current time.

Thanks in advance

Jamie

[OldSchoolRC]

It certainly would, just make sure to set your low voltage cut-off on your ESC. That's a lot of capacity, you'll be wheeling for hours on that thing. I run a 3400 nimh pack and I get almost a solid hour out of it (with a 65t motor though)

[IceChilly]

Thanks Damon...only experience I have with Lipo batteries is with a mini heli that came with a balancer and charger. Been a little intimidated trying it out, but been wanting to go for it especially Im looking at a brushless set up in the future.

[IceChilly]

Ok another question lol. Do I need anything else? (other than the leads) I was hoping this charger would handle the balancing of the lipo battery as well.

[IceChilly]

Im as bad as my wife...indecisive! I hear that its not good to use lipo if you ever want to drive in water. With that said I think I am going to stick with the NiMh's and crossing fingers the New Goat 3S is waterproof

[Wyoming]

Personally Jamie I wouldn't recomend a Lipo to my worst enemy I'd save the money and pick up a couple of high cap 5000+ NImH or 3000nicds they are very tough and don't require special treatment or a fire proof bag to charge them. If you do buy a Lipo check your homeowners insurance policy regarding fires or personal injuries from explosions lol!

[IceChilly]

Personally Jamie I wouldn't recomend a Lipo to my worst enemy I'd save the money and pick up a couple of high cap 5000+ NImH or 3000nicds they are very tough and don't require special treatment or a fire proof bag to charge them.

Music to my ears Seth haha. I already have a 4600 and a few 3600 ones still new in packaging so I will make due with them. :thumb:

The whole fire thing doesnt sound like much fun :eek:

Thanks Seth!

[Budhatrain]

I really do respect people and their opinions on this board... but I would disagree with Wyoming, Lipo batteries really bring alot back to RC... NIMH's and their older brother NICDs are a waste of money compared to what is now available with Lipos and the very least LiFe. Lipos are excellent as long as you follow the rules and their technology has come a long way since they first were introduced. I have never heard anyone who has gone Lipo say "I wish I was running NIMH's again." Couple that with Brushless motor tech- LOOK OUT

First thing I would do is become educated on Lipos- here is a good walkthrough to Lipo education: http://www.rchelicopterfun.com/rc-lipo-batteries.html

From there, spend some time and decide which brand you want to go with and then commit. Personally I choose the Hobbyking way and purchased two Turnigy 2s 30C 5200mah hardcase batterypacks and Turnigy lipo charger for around $100 including shipping.

What's cool about most Lipo chargers is that they also charge NiMh, Nicds and LiFe batteries. Once LiFE battery technology can get more than 6.2v they will be the way to go. Right now they are underpowered which a lot of scale RC's have no problem with so I don't know why you wouldn't at least go LiFe and MaxAmps.

I use a lipo sack to charge and store my Lipo's in and keep my batteries in my metal toolbox for storage- I am very comfortable with this setup and can sleep at night:)

[Arcocustom]

Pioneering work for the lithium battery began in 1912, but is was not until the early 1970's when the first non-rechargeable lithium batteries became commercially available. Attempts to develop rechargeable lithium batteries followed in the eighties. These early models were based on metallic lithium and offered very high energy density. However, inherent instabilities of lithium metal, especially during charging, put a damper on the development. The cell had the potential of a thermal run-away. The temperature would quickly rise to the melting point of the metallic lithium and cause a violent reaction. A large quantity of rechargeable lithium batteries had to be recalled in 1991 after the pack in a cellular phone released hot gases and inflicted burns to a man's face.

Because of the inherent instability of lithium metal, research shifted to a non-metallic lithium battery using lithium ions which is slightly lower in energy density than lithium metal. Long battery runtimes have always been the wish of many consumers and battery manufacturers responded by packing more active material into a cell and making the electrodes and separator thinner. This enabled a doubling of energy density since lithium-ion was introduced in 1991.

Asia produces many non-brand batteries that are popular with users because of their low price. Many of these batteries don't provide the same high safety standard as the main brand equivalent. If a defect is inherent to the electrochemical cell, such as in contamination caused by microscopic Cu, Al, Fe and Ni particles during the manufacturing process, this anomaly will go undetected. With a separator thickness of only 20-25µm, any small intrusion of metallic dust particles can have devastating consequences. If enough microscopic metal particles converge on one spot, a major electrical short can develop and a sizable current will flow between the positive and negative plates. This causes the temperature to rise, leading to a thermal runaway, also referred to 'venting with flame.' and nothing can stop it once triggered. During a thermal runaway, the high heat of the failing cell can propagate to the next cell, causing it to become thermally unstable as well. In some cases, a chain reaction occurs in which each cell disintegrates at its own timetable. A pack can get destroyed within a few short seconds or linger on for several hours as each cell is consumed one-by-one. With the high usage of lithium-ion batteries there are bound to be issues. With a one-in-200,000 failure rate, the maker of the lithium-ion cells, say that on rare occasions microscopic metal particles may come into contact with other parts of the battery cell, leading to a short circuit within the cell. Although battery manufacturers strive to minimize the presence of metallic particles, complex assembly techniques make the elimination of all metallic dust nearly impossible. With lithium-ion batteries nearing their theoretical energy density limit, safety issues are enticing battery manufacturers to change the manufacturing process. Battery manufacturers are beginning to focus on improving manufacturing methods and increasing safety.

Other Safety Concerns
Lithium-ion cells with cobalt cathodes should never rise above 130°C (265°F). At 150°C (302°F) the cell becomes thermally unstable, a condition that can lead to a thermal runaway in which flaming gases are vented. Another safety issue is cold temperature charging. Consumer grade lithium-ion batteries cannot be charged below 0°C (32°F). Although the packs appear to be charging normally, plating of metallic lithium occurs on the anode while on a sub-freezing charge. The plating is permanent and cannot be removed. If done repeatedly, such damage can compromise the safety of the pack. The battery will become more vulnerable to failure if subjected to impact, crush or high rate charging.

[teebeehex]

Thanks for the info Arco, it definitely adds fuel to the fire :p on the discussion of lipo vs old skool. I certainly do appreciate educated input over opinion when making decisions.

[OldSchoolRC]

Really, it depends on your needs.

I can say i run nimh and nicads on my scalers/crawlers just as I don't have a lot of ESC's with lipo cutoff....plus, with slower, higher turn motors, i've never running at full power much anyway, so nimh and nicads are fine for me. Plus, the extra weight is usually not a problem - in fact, it's usually a benefit.

I have made the switch to Lipo for much of my larger brushless rides and all i can say is WOW. No voltage drop off and the power difference to me was simply stunning. My SC trucks and tourers are easily in another dimention of performance with lipo and brushless. They are lighter as well, so lighter weight + more power=FUN FUN FUN! i was really a nitro guy for many years, but BL power brought me back to electric in a big way.

You definitely want to respect the rules for lipo though, I always charge them with the proper safety measures. I use sand bags ilo a lipo sack, but it's the same thing. I've never had an issue, and if you do things correctly, they are very worth an investment imo.

I use a Hyperion charger for just about everything now....very nice units imo.

[Budhatrain]

I think that is a worthy statement- "what will you be using it for?"

Water and Lipos- is no no- not like burny death but short out and no longer work. I just lost one and it was just a little splash. But on that rig non of my other electrical equipement is water proof either- so I should stay away from water altogether.

Lipos packs get damaged in one of three ways- over charge, over discharge or physical damage. Know the rules of the game and your game will be fine.

The lipo cutoff will come more and more standard on new ESC's IMO- however with your nonlipo cutoff esc or older esc's. You can pick up external cutoff or just stop running the rig when the truck is showing signs of loss of power.

As OldSchool said- you get full power throughout the whole packlife- so when there is performance drop- STOP. I have done this and it is working so far.

You can charge a pack this week and use it next week or week afterthat and still have full charge. More power to the truck and lighter weight- easier to keep maintained and in healthy condition.

Personally I use my lipos for my slash- BL clod- and axial crawler. I use whatever half dead NiMh packs on my other rigs that I occasionally bash or let my kids mess around with. When it comes time to buy new packs- I will not look back to NiMh's. I am looking forward to LiFe...

[IceChilly]

Good to hear info and opinions for and against any item. With that one can use the info to form his/her own opinion.

With that said. Would I need a seperate balancer or is this charger/balancer all I would need for charging a lipo battery. (other than the charge pouch)

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXVZA8&P=EP

Thanks

[OldSchoolRC]

Should be all you need! Balancer is built in.

[IceChilly]

Thanks Damon! I started trying my NiMh packs and they seem to be failing. I cant charge them past 500 or so mah out of 4600 and started looking at new packs but since I have already been considering the lipos I figured I would just put the cash towards the lipos.

[Budhatrain]

that's a good charger, if I didn't go the route I went I was gonna get that- amainhobbies is a good site for lipos too. They sell all the major brands and also they have their own house brand called protek. Of course they carry different chargers as well.

I would get a charger that has a built-in balancer. You don't have to and can pick up an external one but it's just simpler.

If you go the towerhobbies route- make sure your a supermember ($15yr)- you get discounts and free shipping over $150. Just for that charger you would get $25 off- if you spent over $200 you would save $35...up to $60 with a $300 purchase.

If you need coupon codes let me know.

PS hardcase for the lipos

[IceChilly]

Thanks Mike. In fact I am a supermember :thumb: I have the codes up to $60 savings on a $300 order if thats the same as you have.

I will take a look at the amainhobbies site as well, but I lean towards towerhobbies because i love their customer service and the easy pay option comes in handy at times also.

[Budhatrain]

yup those are the ones. I am a huge fan of tower. I shop around but tower with the codes works great!

[IceChilly]

Sorry but I have yet another question...I found out that my speed control will only use a 1s LiPo. Now will a 1s 40C LiPo still outperform a NiMh battery?

[OldSchoolRC]

Why will it only use a 1S lipo? I've never even heard of that except for the mamba 1 cell special edition. What kind of speed control is it? (If you are still using the FX-R, it's rated for 2S use)

To answer your question, no - 3.7 volts no matter how many c's will not match up to a 6 cell nimh.

[IceChilly]

Novak Havoc 1S system http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXYDM5&P=EP

Im thinking I made the wrong choice

[OldSchoolRC]

Novak does make good products, but not sure how that's going to work out with 1S. According to the specs, you are looking at 15,540 RPM with a 1S. Due to the gear reduction in the gear box, it may work for you, but I think you will be down on power somewhat. You'll either have to gear up and sacrifice wheelspeed, or gear down and lose some torque. Guess it depends how much power you want really.

I've never tried 1S before, I cannot really say how much power they put out, I'm really just guessing to be honest. I'd be curious to know how it wheels if you decide to give it a try.

I will say my little Stompers (small battery powered cars) and small tamiya snap kits run off 3 volts.....3.7 is pretty low.

[IceChilly]

I found out it has built in lipo cut off circuitry for safe operation with 2s lipo packs :thumb: It has voltage step-up circuitry to supply radio system with the required operating voltage when using 1-cell lipo. (not really sure what that means though lol)

[OldSchoolRC]

Did we lose a post? :)

If it is the Havoc 1S, I'd check directly with Novak (cs@teamnovak.com) and get thier opinion before trying to run on 2S - input voltage specifically says 3.7v, and it does have the smart boost feature for BEC. Not sure where you found your info, but defintely questioning it. From all I've read, these are specifically designed for 1s use only, but Novak should be able to clarify.

As far as the smart boost: Basically, it takes the 3.7v input voltage from the battery and ups it to 6.0 volts so the radio and servos get the correct amount of power (they need at least 4.8v to operate) No idea how that would respond to double the voltage from the battery.

I don't mean to lecture - just don't want you to blow up your new stuff!! :)

[IceChilly]

If it is the Havoc 1S, I'd check directly with Novak (cs@teamnovak.com) and get thier opinion before trying to run on 2S - input voltage specifically says 3.7v, and it does have the smart boost feature for BEC. Not sure where you found your info, but defintely questioning it. From all I've read, these are specifically designed for 1s use only, but Novak should be able to clarify.

As far as the smart boost: Basically, it takes the 3.7v input voltage from the battery and ups it to 6.0 volts so the radio and servos get the correct amount of power (they need at least 4.8v to operate) No idea how that would respond to double the voltage from the battery.

I don't mean to lecture - just don't want you to blow up your new stuff!! :)

Thanks for the heads up, I definitely appreciate it, I too dont want anything to go boom until the 4th of July ;)

Believe it or not the info about the 2s lipo was on the back of the box! Can you believe I didnt even look at that until today, sheesh! I will still contact Novak though. Id rather be safe than sorry.

Worse case is that it doesnt run bad on a 6 cell 3600mah NiMh and its already better than the Tekin system. I was pleasantly surprised that you can set it up with a drag brake! I just was hoping to to max it out with a lipo. I guess its a guy thing, you cant have enough power ;)

[Budhatrain]

Yeah in that article I posted before it goes through the differences between 1s, 2s, 3s etc... what does 30C stand for, all that stuff that will come up when make a decision to buy the right equipment (batteries, chargers, esc).

Real quick each cell represents 3.7v- so a 1s will have 3.7v, 2s will have 7.4v (close to a regular 6cell NiMh pack) 3s will be 11.1v etc... it's a lot to take in, but once you start to get it down it's not that big of a deal and then places like hobbyking and amainhobbies or towerhobbies start to make sense with all their battery options.

For most applications I stick with a 2s pack- unless your esc can handle more like a 3s (BL Emaxx, Revo, BL Slash, Mamba Max) etc...these you can go bigger but its like ludicrous speed from spaceballs- or even worse plaid speed

here's that link again: http://www.rchelicopterfun.com/rc-lipo-batteries.html

Hope this helps

[IceChilly]

Thanks Mike. Funny I know I remember reading that article but I forgot where it came from. It is starting to make more sense to me. Its just new to me and I want to make sure I cover all the bases before I do what Damon mentioned...BOOM! lol

[IceChilly]

Well I got the email from Novak and it is only compatible with 1s lipo and if i continue using 6 cell nimh I will ruin the system. Wow. I called up tower and they wont take it back since its been already installed on my vehicle. So I guess Im out $159. To top it off I sold my other speed controls. Oh man, Im not having much luck lately :(