engriso

Hi Gang,



been enjoying my bandit vxl.


I need another battery to enjoy more time with it.



Please help with this question



If I have a NiMh 7.4 5000mah compared to a Lipo 7.2 5000mah battery.


Do they both last the same time for car usage?


Will each battery give me the same performance?


The sales guy is telling me that a 7.2v 5000mah lipo will run the car faster and longer duration that its NiMh equivalent?

is this true or is he trying to sell me the $$$$$$ lipo?


I was going to purchase 2 5000mah NiMh instead of the one lipo


Can someone please correct my enquries with common sense answers please


cheers


Eng

ThunderbirdJunkie

My Feedback: (3)

Eng, the lipo will be lighter, and has less internal resistance, so basically

Your car will feel absolutely ballistic with the 7.4v 2S lipo compared to the 7.2v NiMh.

ThunderbirdJunkie has been meaning to take some video of LiPo vs NiMh.

A generic $20 HobbyCity Zippy 2S pack craps all over one of ThunderbirdJunkie's $75 GP3300 SMC matched NiMh packs. You DO, however, need a LiPo-specific charger.

ThunderbirdJunkie is still a LiPo newbie, but without LiPo, he would've never gotten back into electric.

TIGER76

LIipo will discharge alot higher rate providing more power and run time hell my m8s 7.4 lipo keeps up with my 9.6 8cell nimhs[X(]

engriso

Thanks for the replies.


i have a proper charger that does all battery types.


I was just asking because I am more so wanting increased run time as opposed to high speed.


So i basically thought it would be cheaper buying another 2x 8.4v 5000mah NiMh batts than just one 5000mah LiPo


My understanding that the higher voltage input would give you higher speeds and that the higher the current rating would achieve longer runtimes.


I just wanted to compare the same current outputs for two different types of batteries with respect to run time

Two NiMh's at 5000mah would be cheaper than 1 LiPo 5000mah


Cheers


Eng

guver

My Feedback: (325)

The voltage will determine speed , but it is the capacity that determines runtime. 10,000 mah will run much long than 5000 mah. If it is "runtime for little cost" you want then get the pair of NI batts.

hhvg

Capacity can also determine speed in lipos as well. Its usually on a few MPH though more noticeable when leaping from like 20c to 40c for example.

Yep. Even considering a lipo 5000 will have the runtime of like a NIMH 6000? one lipo 5000 is going to have less runtime than nimh 10,000. Performance wise the lipo is the way to go.Each 5,000 nimh is going tolose punchat around the last 1,000-1,500 mah in the pack any ways even with brushless.Your equipment will run a little cooler longer too w/lipobecause lipos can supply the amps required for the whole run. Id be thinking to myself"would I rather have 2 packs w/3,800mah each of great performanceor one lipothats about equal to 6,000mah nimh runtime/great performance the whole way through?' I think if you could only afford one lipo now thats the way to go and save up for another. Thats what Id do.

john01374

engriso - There is no reason to buy NiMh period. Everything listed here so far is true. They are lighter, have a higher discharge, and will generally run longer with the same Mah rating, more then 3 times as many cycles and then there's cost... They are cheaper, a lot cheaper than NiMh packs. I'm not going to recommend a specific brand as that typically turns into a fight when everyone sticks up for the brand that they own etc. If you want recommendations PM me.

A 2S lipo in a VXL bandit is a bullet. You'll pick up a couple of miles per hour on the top end but what you'll notice most is a major increase in punch. My Bandit will flip over backwards on 2S pretty much anytime I want it to. Get it rolling around 25mph and punch it and the front comes right up. On 5000mah I'm getting around 30/35 mins in the bandit.

I will caution you on two things. 1) Do your homework on charging, balancing and storage. You do need to respect the batteries. 2) DO NOT get caught up in the hype that LiPo's are dangerous. They are no more dangerous that NiMh. Truth be told NiMh packs are much more violent when something goes wrong.

Since you are running a VXL ESC I would recommend you get a couple of LVA's. I say that because some people have had issues with the LVC cutting in early or not cutting in at all on the VXL ESC and for $3 the LVA is just a good backup.

If you have specific questions on LiPo's handling etc feel free to PM me. I've been using them for 5+ years without an incident.

qoisdhc oqina

My Feedback: (-1)

FALSE

People that dont want to deal with lipo
People that dont have the money for a new charger and new batteries
Race classes that dont allow lipo
Race class with friends, no one runs lipo, want to keep it fair

I can go on and on, if you keep stating bs statements i will.

ThunderbirdJunkie

My Feedback: (3)

That's like saying us winning the Cold War by outspending the soviets was unfair[&:]

john01374

1) I'll give you this one as we live in a society of people who just don't want to learn. And it's really too bad as LiPo's are a whole lot easier than NiMh. The biggest plus in handling them is you can put then away for extended periods of time and not worry about cycling them.

2) If you can afford 1 decent NiMh battery you can afford a Lipo charger, balancer and batter.

3) I haven't seen a class in 2 yrs that doesn't allow at least 2S lipo. Even spec slash allow that...

4) I'll give you this one as well. As we agree there is a clear advantage to running the Lipo.

qoisdhc oqina

My Feedback: (-1)

Advantage yes, but no reasons to run nimh is just not true.


Kids car.Parent dont want to teach them, dad doesnt want the car being that fast.
Someone learning.Dont need the speed.

Edit, about lipos being easier...Not necessarily.
True, you can leave them for extended period of time.
However, they have to be at the right voltage, and im sure some people run a pack until the lvc kicks in, throw in on the shelf and go on vacation for a few weeks.
Nimh, just unplug it and your done.

However, nimhs do blow up quite a lot...

Shabbernigdo

IMO nimh are better in rc tanks and crawlers / trail rigs.
added weight helpswith tractionand high draw /voltage is not nessary as yourarly spend any time at or near full throttle.

Iget my 3000 mah nimh packs for like 5 to 10 bux. i dont think there is a lipo to match that

savagecommander

john beat me to it-

i think its stupid to say someone would run a pack to LVC then go on vacation for a few weeks.... that really isnt helping your argument

theres no contest. you can get batteries and a charger for probably the price youll pay for just your NIMH packs...

just buy one and i'll bet dollars to cents youd never buy another NIMH pack- i know i wont.

qoisdhc oqina

My Feedback: (-1)

Alot of people, dont read up on things before they buy.They just buy em.Someone walks into a lhs, asks for a battery, owner sells em the expensive lipo to make money.They go home, use it like they do a nimh.They dont know you have to leave charge in em.
Alot of times i use a car, and either it breaks, or i dont run it for awhile.Either way, sometimes it and the batteries sit for awhile, a week or 2 or more.
What happens when that happens to someone else?They dont charge the lipo, common sense tells them you dont charge the battery and let it sit.


Bet away.Ive bought many lipos, and OMG SHOCKER guess what, ive bought nimh after that!!!![X(][X(][X(][X(]

savagecommander

never heard of a LHS selling a lipo and not explaining how it works- although im sure youll support your argument however you can. and i was talking to engriso about buying one-

qoisdhc oqina

My Feedback: (-1)

Really?Youve been to every lhs, including the ones in engrisos area, and bought a lipo and saw if they explained or not?
Ive never heard or a lhs explaining how a battery works either...
I think everyone knows how a battery works, it send current to something else.
I will support my argument however i can...Seems your doing the same.
It was a statement.I responded to that statement.
Unless im not allowed to do that anymore...

savagecommander

well, at my LHS they do explain how batteries work, and how lipos work so when people buy them and dont use them properly, they arent coming back into the store wanting thier money back.

but i guess since youre so educated on the subject, you probably knew that.

trollers aside, NIMH arent any match for LIPO.

qoisdhc oqina

My Feedback: (-1)

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Candre23

My Feedback: (8)

This thread has gone full retard.

NiMH is an old, inferior chemistry. There are situations where they might be preferable to lipo, but they are few and far between. For almost everybody, almost all of the time, lipo is the better option. It provides more power, higher capacity, lower weight, and more voltage options. Both the packs and the chargers are as cheap as (or cheaper than) NiMH if you know where to shop.

But just like uncle Ben said, "with great power comes great responsibility". In exchange for much higher performance, lipos do require a bit more attention - don't over or under charge them, balance them on a regular basis, and don't feed them after midnight. If you can handle those few simple rules, your car will run faster for longer. If you can't, they'll explode and/or transform into gremlins. It's that simple.

rcaddict0

lol...I would have to agree that Lipos are a better battery all together. I think there as safe as any battery if used right. If your limiting your self to buying them at your LHS then I could understand your concern with the cost. There $69.99-$99.99 at my local shop. Go to www.HobbyKing.com and pick your self up a few hardcase lipos at $20 each and a decent charger for $20 and $80 your set! An hour of running between the two and it wil be the best investement you'll ever make for your Bandit.

on_your_six

My Feedback: (11)

I have been running Lipos for over 3 years now. In the last year or two (since the price has dropped substantially) lipos have become the battery of first choice for me. I have in my hand a new battery just off the boat from Hong Kong that charges at 5C... I don't even have a charger that will go that high (YET)... It is now possible to go to the field and fly continuously with three or four batteries. You can charge them almost as fast as you use them... The batteries have outrageous discharge rates of 25-25C that is 110 to 220 amps in my case.

Of course you need BECs or voltage regulators to power your flight receivers and servos... but some manufacturers are moving to raise those voltages. With these batteries, you need to learn how to use them. They must be charged and discharged correctly. They need to be correctly sized to the application and you will need some meters you probably don't currently own. You need to charge them where they cannot cause damage if something happens. I have never had a problem but some have had fires. Never treat them like NiCds or NiMH batteries.

By weight and power, you cannot beat them. They can be used on planes from .25 ci all the way to 50cc glow and gas engines. I have not seen anything larger, but nothing prevents it.

kaiser01

i love lipo. it's helped the hobby so much. i still have a couple of nimh's and nicads for my vintage tamiya's but the rest is all lipo.

no fires, no dead cells, all power all the time, doesn't drop off like nimh and nicad. i never have a hot bettery either.
lipo and bl motors have helped me understand gearing better too.

hobbywing/turnigy/hobbyking/zippy/flightmax are the best thing to happen to lipo as well.

one thing to note about lipo's that claim to charge at higher than 1c:

i have seen two that say this, but then on another sticker on the back it says do not charge higher than 1c.

one of the packs (tenergy) was charged at 3c (thats what it says to charge it at on the lable) and died in a week (this was my friends pack, charged on a triton eq)

now i have the same pack (tenergy 5000mah 2s 35c) and only charge at 1c and it's been fine.

after seeing that i charge all lipo (no matter what the lable says) at 1c.

two other guys at the track have similar problems with some name brand packs that say they can be charged at higher than 1c.

Old Sloppy

In the end it is a matter of which cell type will make you the most happy.
The enhanced fun (higher speeds) with Lipo will make you more happy than the enhanced run time (lower speeds) with Nimh.


Lipo's main advantage is the low Internal Resistance, compared to NiMh.

A Nimh cell had a 15c rating (aprox.) so a 3300 would discharge at about 49.5 amps .
This ment the cell would be at maximum tempture due to the IR.

A tipical Lipo will have lower IR and will not get quite as hot.
The lower the IR the higher the "C" rating, so a 20c Lipo will discharge at 66 amps.

Now a days most Lipo's have a 35c or 45c rating, so it can discharge at 115 amps ( 35c) or 148 amps ( 45c) at about the same tempature as the Nimh cell.

This "reduced heat" allso is an advantage when charging, a Nimh cell liked to charge at 0.5 C rate or 1.65 amps at a given tempature.
My older generation Air Thunder Lipo will charge at 1 c rate, most current Lipo's will charge at a 5 c rate.
So that 3300 Nimh takes two hours to charge at 0.5 c rate, a 5 c rate will take aprox. 12 minutes to recharge.
Of course no Nimh cell ever had a 5c rating, so I am refering to a Lipo cell in this 12 minute example.

Another advantage is Voltage Drop under a load, so your 7.4 volt Nimh can drop to 6 volts when loaded (under full throttle in your RC car)
A comperable 7.2 volt Lipo can drop to 7 volts under the same load so Your motor will see a 7 volt Lipo compared to a 6 volt Nimh.Next advantage is weight, a Lipo weighs about 60% of a Nimh. In my case (I like FE boats) my 19 pound Lipo powered boat would weigh about 24 pounds if powered by Nimh cells.
This one fact alone makes for faster acceleration and improved handling as well as higher top speed (62.5 mph on GPS)

Harry

Ov course their are other applications that favor Nimh (rock crawlers or tanks or any application where traction needs override the need for power)
I for one prefer my reciever pack to be a 5 cell 300 mah Nimh pack.

Harry

ThunderbirdJunkie

My Feedback: (3)

Thanks for that Sloppy! Got another wrinkle on the brain!

Old Sloppy

Uncle Ben said that ??????????????

Gee Wizz, I thought he simply sold bags of rice .................(He,He,He)

Harry [8D]