lipo help!!!

[lordjasper1988]

hey guys when it comes to batteries, im a nimh guy all the way but im thinking of going to lipo.

im starting this thread for all those thinking of going over to lipo but who are cautious about the safety issues and prices. like myself.

please put as much knowledge as you can on lipos here, put your safety finds and all your shopping finds for example battery finds, charger finds, balancer finds etc. please put where you found said finds and price so to help those who need them.

when it comes to your advice and info please keep it simple so as not to confuse those not in the know (like newbies like myself lol) also please post if anything went wrong or brands you approve/disapprove of.

 

[bouncingbabyboy]

My 2 cents: I had the nimh that came with the micro dessert truck and the one that came with the trekker. I got the lipo originally for the dessert truck because the price is the same for the lipo charger and the nimh charger. I love it in the trekker. Losi sells a peak charger for the nimh, but the one that comes with the trekker is not a peak charger. The nimh battery gets stupid hot so saying the lipo is not as safe is not accurate. A peak charger makes either safer. We can all agree that the battery powered charger that comes with the micro crawler should go straight in the trash and you should buy a wall charger. Therefor I would recommend making the lipo investment early rather than later. Under the "post your battery find" thread I saw someone had a 4.8v lipo if you are trying to slow it down without gearing, new motors and adding a bunch of weight.

 

[spoo76]

My 2 cents: I had the nimh that came with the micro dessert truck and the one that came with the trekker. I got the lipo originally for the dessert truck because the price is the same for the lipo charger and the nimh charger. I love it in the trekker. Losi sells a peak charger for the nimh, but the one that comes with the trekker is not a peak charger. The nimh battery gets stupid hot so saying the lipo is not as safe is not accurate. A peak charger makes either safer. We can all agree that the battery powered charger that comes with the micro crawler should go straight in the trash and you should buy a wall charger. Therefor I would recommend making the lipo investment early rather than later. Under the "post your battery find" thread I saw someone had a 4.8v lipo if you are trying to slow it down without gearing, new motors and adding a bunch of weight.

The safety concerns with Lipo isn't about heat.
its about how dangerous they are IF they do explode. they shoot out flaming debris that isn't easily put out.
( plenty of videos found online )
but with proper care you will be fine

for a charger you want to look for a LIPO BALANCE charger not peak charger.

the voltage for each lipo cell is about 3.7v
a single cell Lipo ( 1S ) is 3.7v volt not 4.8
2 cell ( 2S ) is 7.4
3 cell (3S ) 11.1 and so on and so on

some use a single cell to slow down the crawler as a 2s ( 7.4V ) can make it fast for some. but you will also lose some power and torque and the stock ESC does not have a low voltage cutoff for single cell


Search around the forums for lipo info and you will find more than you know, reviews,quality,price, places to purchase from ect

its all been asked and answered here already. you could even find what you need in the losi micro area alone

I wont get into brand recommendations as again there are plenty on here. but for safety I would recommend a Lipo bag just in case. they are very cheap peace of mind

 

[anthony]

i used a 7.4v 300 mah 2s lipo losi battery with the stock motor and the motor got soo hot i could smell burning? and i didnt want to destroy the motor si o shut it down, i wouldnt reccomend that battery thats really the only lipo i had, i think i need to go alittle lower on the milliamps like a 150mah?

 

[spoo76]

mah is capacity and has nothing to do with motor temps in this case.

for those looking for a 2S 300mah hobby king just got these back in stock for under $3
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9028

 

[Ramination]

Couldn't the extended run time of a 300 mah over a 150 cause the motor to overheat?

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[spoo76]

I guess maybe it could if you were running for extremely long times and running it hard. but that shouldn't be the case with only 300mah. assuming no other issues,stock sprur&pinnion and you arent running it hard i would suggest check for binding in the transmission, Slipper,or wheel nuts

 

[johnnyh66]

Couldn't the extended run time of a 300 mah over a 150 cause the motor to overheat?

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I gotta go with spoo on this. I've run multiple 2s lipo's through mine back to back with out any trouble. The motor will heat up but not to the point I was worried.

 

[spoo76]

I gotta go with spoo on this. I've run multiple 2s lipo's through mine back to back with out any trouble. The motor will heat up but not to the point I was worried.

Yes that is a good point to bring up for those who may not know. it will get pretty warm. but it shouldn't feel burning hot or have a burning smell

 

[lordjasper1988]

hey guys, thanks for the safety stuff on runtimes and batts but the main thing im trying to find out for myself and other lipo newbs is how to charge, ballance and maintain lipos, eg, which chargers you recomend or how to safely charge and use lipos. i really wanna try lipo but... its the charging im concerned of, and i think others are aswel :s

 

[Tuna]

Agreed, I haven't taken the plunge to lipo as I just don't feel I know enough about them. Thanks to the above posts for explaining the "Cells" on a lipo.

I came back to RC's after many years away and all this lipo talk had (and still has) me quite confused.

 

[Evilinside]

The extra heat is from the extra voltage. That's it.

Longer run times do not cause heat issues unless there is something else going on. However with Brushed motors, constant back to back to back use (aka long run times) is super hard on the brushes. Combine that with the relativity cheap Losi motor, and the extra heat and speed from the higher voltage of a 2s lipo, and yes the motor will not have the longevity it would have had with nimh.

Get a high turn brushed motor, or a brushless motor, and those are no longer issues.

But LiPo is by far superior to nimh. Faster charging, more amps, more voltage, longer run times, consistent run times, etc.

 

[spoo76]

hey guys, thanks for the safety stuff on runtimes and batts but the main thing im trying to find out for myself and other lipo newbs is how to charge, ballance and maintain lipos, eg, which chargers you recomend or how to safely charge and use lipos. i really wanna try lipo but... its the charging im concerned of, and i think others are aswel :s

the HOW depends on the charger and options. but generally you just use the balance plugs. some balance chargers use the balance plugs and the power plugs.

get yourself a lipo bag to store the lipo in when charging, its very cheap insurance and if the lipo does ever explode when charging the bag prevents things,people,and pets from catching fire.

as far as recommendations on batteries and chargers there are plenty of threads about lipos In the micro area with reviews & links.

for a charger I personally use the eco-6 from hobby king its $18 and a 5amp clone of the Turnigy accucel 6
however the Hobby king eco6 is out of stock

the turnigy is only $5 more and doesn't need an adapter for the lipo balance plugs ( not that it matters)
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=7028

for Lipos do a search in the micro forum there are many threads with links and reviews just about lipo.
I generally just look for a 2S battery that will fit.
the packs i have range in capacity from 200 or 220mah to 360mah and the C/burst ratings vary

 

[lordjasper1988]

thanks very much guys this is helping alot just one last question guys... whats the c burst rating for cos i have seen them go from like 10c up to 45c on hobbyking.

 

[spoo76]

So what you are saying is you still havent searched any threads for any info :lmao: burst rating = burst of energy. the higher the rating the higher the temporary burst is. its the oomph when you first give it throttle. its not important enough to look for high numbers with these small micro crawlers. But if your crawler is heavy and has alloy weighted wheels and bigger tires it wouldnt hurt

 

[Evilinside]

thanks very much guys this is helping alot just one last question guys... whats the c burst rating for cos i have seen them go from like 10c up to 45c on hobbyking.

Yeah bud, do a search on that one. Your C times your voltage gives you the mah. Do a search on that to find some very good detailed descriptions.

 

[benoj]

Your C times your voltage gives you the mah.

Thats incorrect. your c rating times the mAh /1000 = the amount of amps the pack can safely put out continuously. ex 150mah 15c = 2.25A

 

[Evilinside]

Thats incorrect. your c rating times the mAh /1000 = the amount of amps the pack can safely put out continuously. ex 150mah 15c = 2.25A

Yeah, what is in my head is correct, but yeah, the wording is all wrong, I wasn't talking about the math... poor wording, whoops, happens sometimes.

The bottom line was to do the search for a good explanation on it, lol. But what was in my head that didn't translate well to a quick sum up was... the C rating determines the current you can keep under full load at the rated voltage, a higher C will provide more current and hold a better voltage through the life of the mAh. So the C times the voltage gives you the mAh wasn't a sum up for a math problem, it was a sum up for the provided current at the provided voltage for your life of the charge. I'm not a teacher, lol, hence the suggestion to do some google or forum searching!

And the voltage is a set by the number of cells.

 

[MAXXMASHER]

The bottom line is, once you try a lipo, you'll never go back. I already had lipos for my other RC's, so getting a micro lipo was a no brainer. Just make sure you get a balancing charger. I gave half my Nimh packs to my bro for his crawlers. With just two lipos, I can out crawl him (time-wise) every time, and he has to keep changing battery packs. Throw in a radio system that you can dial the throttle exponential and it greatly increases your performance. (You can creep along and then when you need it, you have enough power to balloon those little tires.) I did a rover build and ordered two cheap 850 mah packs from Hong Kong that just barely fit under the hood. With two packs, I can crawl forever. I think the packs cost less than $10 for both. Best upgrade ever!!