Sudden reduction in speed and battery life( metal track ups)

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Carrion
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Sudden reduction in speed and battery life( metal track ups)

Post by Carrion »

So my metal tracks for my tiger 1 arrived today and have been fitted.

on the first run out the tank didnt seem as fast. normally its at my walking pace or there abouts and this time it was lower. in addition the battery life was much shorter than normal. before i was over half a mile worth of constant driving, this time it was less than 300 m.

so is it simply the extra weight of the metal tracks or as i suspect, have i over tensioned the tracks resulting in to much friction and the motors having to work that much harder?
If all else fails your just not using the right sized hammer.
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jarndice
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Re: Sudden reduction in speed and battery life( metal track

Post by jarndice »

The metal tracks on a Tiger 1 should come off the top of the front sprocket and completely clear the first outer road wheels and then clear the first inner road wheels only just touching the second outer road wheels.
Just look at pictures of the prototype and you will get the idea.
Inertia alone will cause the Tank to be slower moving off,
Most people prefer it as it does look more like the real Tank.
The increased load on the drivetrain will certainly affect the life of the battery.
I think I am about to upset someone :haha:
Jofaur86
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Re: Sudden reduction in speed and battery life( metal track

Post by Jofaur86 »

Hello,
Kind of batteries ? Capacity ( Mah ) and type of charger used ??
Carrion
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Re: Sudden reduction in speed and battery life( metal track

Post by Carrion »

1800 MAh NiCd naff ones that came with the taigen tank so not expecting as much
charger is a bigboys toys one i got instead of using the rear charging port as i have issues with charging batteries in things from my airsofting years

as a side if i run the Lipo that came with the t34 would that cause any issues? same voltage
If all else fails your just not using the right sized hammer.
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jarndice
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Re: Sudden reduction in speed and battery life( metal track

Post by jarndice »

Taigen/Torro advise against using a Lipo in a Tank with a V2/V3 mfu.
If you can work out why a battery of the same voltage and output can if it is a Lipo harm your Tank when a NiMh or Ni-Cad of the same voltage and output will not then you are a better man than me BUT a few years ago there was a problem with Lipos operating in a Clark mfu equipped tank and it was suggested that initial start up on a new Clark board using a Ni-Cad or NiMH first then changing to a Lipo would sort out the problem,
Why ??? I have no idea :lolno:
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Jofaur86
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Re: Sudden reduction in speed and battery life( metal track

Post by Jofaur86 »

Hello :D
Indeed,this type of battery is to be avorded on a unsuitable electronics :O In addition the charge must be done with a spécific charger and no just any toy ( diffèrent technology ) at the Risk of explosion ,and fire. :thumbdown: Type of battery must not be charged below a certain voltage,for this reason Elmod,for example is equiped wuth a system allows automatic cutt off,of the power supply the charge of these batteries must be done in safety bag,and spécific cgarger,with balance,not to be stored anywhere,and preferably on métal box .I advise you to return to Nimh the Lipo :S being more réserved for master modelkers perfectly this technology :thumbup:
Jofaur86
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Re: Sudden reduction in speed and battery life( metal track

Post by Jofaur86 »

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Son of a gun-ner
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Re: Sudden reduction in speed and battery life( metal track

Post by Son of a gun-ner »

1/ Lipo batteries are not the same voltage, the 2 cell ones are 7.4 volts, but when fully charged, they can be over 8 volts.
2/ when using Lipo batteries, the electronics have to be designed to support Lipo batteries, well any type of Lithium battery. This means that the electronics are designed to stop these batteries from discharging too quickly. Samsung got these electronics wrong with the original S7's, and some of them were bursting into flames. The same goes for charging, they have to be charged at a controlled rate. EE had to recall their free pocket chargers, because they got the electronics wrong, and those chargers could catch fire. They were offering £20 to anyone that had that free charger to bring it back, such was the danger. And these examples were with the more stable Lithium types.
3/ don't let this put you off, when all goes as it should, it all seems to go well.
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Max-U52
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Re: Sudden reduction in speed and battery life( metal track

Post by Max-U52 »

They recommend against lipos to protect themselves. There is a possibility that the Lipo can cook the board and they don't want people returning entire tanks because they got them and put the wrong battery in and fried the board. Myself, I use lipos in my taigen tanks all the time and I've never had a single problem. The only time I've ever had a lipo cook an mfu was when I tried to use dual ratio gearboxes (5:1) in a King Tiger and it just couldn't handle it. Other than that, I've never had any trouble, but I still don't advise that you do it. Because it works for me, doesn't mean it will work for you and I would hate to be responsible for frying anybody's tank.
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Jarlath
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Re: Sudden reduction in speed and battery life( metal track

Post by Jarlath »

Max-U52 wrote:They recommend against lipos to protect themselves. There is a possibility that the Lipo can cook the board and they don't want people returning entire tanks because they got them and put the wrong battery in and fried the board. Myself, I use lipos in my taigen tanks all the time and I've never had a single problem. The only time I've ever had a lipo cook an mfu was when I tried to use dual ratio gearboxes (5:1) in a King Tiger and it just couldn't handle it. Other than that, I've never had any trouble, but I still don't advise that you do it. Because it works for me, doesn't mean it will work for you and I would hate to be responsible for frying anybody's tank.
I've run a highly customized Heng Long Tiger I at public meets for anyone to try out.
The Toothless Tiger has no turret, all plastic running gear, zinc gearboxes with heatsinks on the motors, a secondary cooling fan in the hull and a Taigen V2 MFU. It has run through 4-5 5000MAh Lipo battery packs so far w/o an issue. Now that being said the original HL 2.4GHz MFU died on the second battery pack and then I added the additional cooling fan an the fan cooled Taigen MFU.

All my other tanks run aftermarket boards, using 2S lipos with LV alarms. I use a multitude of chargers (Decent ones) and ensure that they are charged properly. A regular occurrence on our battlefields is the warbling low voltage alarm that people cannot hear (cause they are deaf as posts!).

Back to the OP question though...
Think of it this way. The driveline sources of power consumption are as follows.
  • static/rolling friction in the axles of road wheels/idlers
  • torsional force required to push/pull tracks and overall tank
  • friction/losses caused by resistance of travel surfaces
Metal tracks add a lot of mass to a tank which then adds friction onto the axles themselves. Tension may also effect it, as loaded suspension = friction.
Energy Consumption (W/hour) = Force/time, force is directly effected by mass & friction (More mass & More friction = higher forces)

A 7.4V 2000MAh battery has a nominal energy output of 14.8 Watt hours.
F= mass * accel/gravity * friction coefficients. So when you increase mass, increase friction coefficients (Resistance in axles/surfaces) = that much less run time.
Which is why people start adding bearings into roadwheels and idlers so as to reduce friction. Heavy metal tracks = more surface resistance.



My son uses an all plastic HL KT that runs for almost an entire weekend of battling on a 5000MAh Lipo battery. My 10kg Taigen KV-1 runs for maybe 1/2 a battle day on the same battery...
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