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Spetz83

Please Explain Lipo Batteries

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Hi guys,

I don't understand lipo batteries. I keep seeing people referring to 2S 3S and other names for them.

How many volts are they?

Are they physically bigger than nimh sticks?

How come people can't always fit them without modifications?

Also, would a cheap NiMh pack be able to power a ezrun brushless system? (5 turn or so?)

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Hi guys,

I don't understand lipo batteries. I keep seeing people referring to 2S 3S and other names for them.

How many volts are they?

Are they physically bigger than nimh sticks?

How come people can't always fit them without modifications?

Also, would a cheap NiMh pack be able to power a ezrun brushless system? (5 turn or so?)

2S, 3S is how many cells are in the pack. Each cell is 3.7v, so 2S is 7.4V

They come in many different sizes, but it can be hard to fit some of them in Tamiya cars due to shape/size.

A cheap NIMH pack will run the 5.5T Ezrun, but it can cause stuttering, with smaller capacity, or older packs due to the pack not delivering enough power. It seems the larger the NIMH battery, the better they run however, and something like a 5000mah NIMH should be pretty good from my experience.

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team orion and thunder power both make hardcase lipos with rounded edges (6 cell stick pack shape) that will fit most tamiyas.

they are not cheap though.

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Hi guys,

I don't understand lipo batteries. I keep seeing people referring to 2S 3S and other names for them.

How many volts are they?

1S = 1 Cell = 3.7V

2S = 2 Cell = 7.4V

3S = 3 Cell = 11.1V

and so on... but I have noticed my 2S hits 8V easily after a full charge :lol:

Are they physically bigger than nimh sticks?

How come people can't always fit them without modifications?

If you want compatibility with most Tamiya, find a 2S battery in "stick pack". They will generally say if they can fit in Tamiya cars. The "square pack" are for newer R/C chassis designed for Lipo so they are not rounded and have a flatter battery tray.

Also, would a cheap NiMh pack be able to power a ezrun brushless system? (5 turn or so?)

Voltage is voltage, so yes it'll be fine.

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Cheaper NiMH packs tend to drop voltage under load, hence the stuttering. Modifying the punch settings on the ESC can work around it.

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I tried a core racing 5000mah nimh with my 5.5 Ezrun system and it wasn't up to the job. Lots of stuttering and lag. If you're only bashing then the overlander lipo series are good IMO. Soft case so can fit where a 6cell stick pack would go

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Voltage is voltage, so yes it'll be fine.

Voltage is similar between Ni-MH and Li-Po yes, but this isn't why it stutters on cheap Ni-MH packs. It's current draw (Amperage) and the discharge rate (or the lack there of) of Ni-MH packs. Basically Ni-MH struggle to deliver enough amps to drive a brushless system, especially the high powered systems.

A 4000mAh 25C 7.4v Li-Po is capable of supplying 100Amps of current, much more than a Ni-MH could ever supply.

Soft case so can fit where a 6cell stick pack would go

You run a very high risk of Li-Po fire by using soft packs in land based vehicles. The vibrations of running can wear holes in the soft skin. Sticks and rocks can easily puncture the thin skin. Landing from jumps or a crash can distort the pack.

Once it starts burning it's bye bye car, buy a new one!

It is highly recommended you use hard case round edge packs in Tamiya chassis where the hard square case packs don't fit. There are many brands making round edge hard case packs. I use IP4000 25C round edge hard case packs myself. The last packs I bought were AU$35 each. The hard case packs don't just offer a hard shell to protect the pack, they also have padding inside to casing to make them shock proof to a degree.

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A lot of Lipo packs, even the stick packs, won't fit your old cars without modification. The Lipos always include very large wires that really cause problems in some vehicles. Personally I opted to buy lipos that have the bullet style holes in the top corners of the packs. These fit anwyere old stick packs fit and only require minor drilling in the chassis to make way for the bullets. Of course either style pack will run better than any nimh any day of the week. I will NEVER buy a nimh pack again...

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Since I tried a LiPo battery once, I am not keen on going back to NiMh. Sometimes the batteries are indeed hard to fit, even the stick pack shapes ones. Sometimes they are to long for stick pack slots, then slightly too high, or the rounded of edges are different than Tamiya engineered them into the car... etc.

The car which had the hardest fit so far for a LiPo was my TA03F with FRP chassis plate conversion. The Yeah Racing 3200mAh 20C LiPo Battery (Relabeled Team Orion battery I believe) was simply ever so slightly too wide, as even a regular stickpack would have a hard time fitting in there, it didn't slide in or out, it had to be pushed in and out (let alone what happened when sand and small debry came between the battery and the chassis bits) ;) On my TB-01 I have to fit it upside down (for some strange and dark reason it won't fit with the 'right side' up, but when turned around, goes in the slot instantly) :)

However, It´s well worth finding solutions for these problems by modifying a part or the chassis to make it fit. The LiPo batteries if handled correctly are completely safe. They, like mentioned before, have a better capability of powering the higher drains that the high brushless systems demand. They are lighter (which can be both an advantage or a problem, depending on the car you drive), the charging time is very short, and the the car will deliver the power consistently throughout the run until the end, where you may notice a drop-off, whereas with Nickel batteries you see the power decreasing long before the battery is actually 'empty.'

So what chassis are you running currently? It may help, as the chance is big someone here on TC (and even someone that has replied) has already tried to fit a LiPo in them ;)

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And the C rating is basically how many continuous amps it can deliver without issues?

Are there 3S lipos which are still the same size/shape as a 7.2v stick pack?

And, I was looking at the Duratrax ICE charger, but as I understand I also need to buy a balancer on top of the charger?

Pretty expensive conversion to be honest. Charger + balancer + a few batteries can easily run up 300+ USD

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And the C rating is basically how many continuous amps it can deliver without issues?

Are there 3S lipos which are still the same size/shape as a 7.2v stick pack?

And, I was looking at the Duratrax ICE charger, but as I understand I also need to buy a balancer on top of the charger?

Pretty expensive conversion to be honest. Charger + balancer + a few batteries can easily run up 300+ USD

My post here is on this exact topic of whats good:

http://www.tamiyaclub.com/forum/index.php?...c=58989&hl=

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And the C rating is basically how many continuous amps it can deliver without issues?

Are there 3S lipos which are still the same size/shape as a 7.2v stick pack?

And, I was looking at the Duratrax ICE charger, but as I understand I also need to buy a balancer on top of the charger?

Pretty expensive conversion to be honest. Charger + balancer + a few batteries can easily run up 300+ USD

I think there are no 3S Lipos with stick pack size - and if they exist, they may well have a low mAh rating (as it seems the bigger cells can generate more amperage).

As for the charger, I'd buy one that has an integrated balancer function - and the brand you buy really affects the price a lot. There are many B-brands that have re-labeled A-brand batteries, at only half the price of the A-Brand. The same applies to the chargers. However, it's better to invest in a more expensive one if you're really into RC. The charger will easily carry on charging for 10 years unless you're not treating it right - as for the LiPo batteries, their life span is also much greater than NiMh batteries if someone hasn't mentioned that (they can recharge many more times before they noticeably degrade in capacity).

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