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Electric Guide


Garry

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  • 2 years later...

Just to say: A brushless motor is a motor that is electronically controlled not mechanically. Instead of using connection wires to change polarities inside the motor, a circuit board does it instead, this allows for the motor to spin at much higher speeds and save power.

Edited by DataMatrix
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  • 5 months later...

General guide for charging rates of cells

Remember, these are guidelines only, and although certain brands of cells can take higher rates, the risk associated with it increases too.

The author of this guide takes no responsibilty for the consequences following this advice. If in doubt, get a second or third opinion.

A couple of pointers first though, if you haven't got a delta peak charger that you can adjust the amperage in individual amounts (like 0.1A increments), save up and get one as soon as you can. And when the term '1C' is mentioned, it means the the capacity of the pack as the charge rate (4200mah = 4.2A, 3600mah = 3.6A etc).

Basics:

In general, the higher the charge rate, the faster the pack charge. BUT, the charging process will heat the cells up. Up to a point, this is a good thing, but beyond that, the cells will start to leak/vent, and possibly explode. Too hot to touch is deffo a problem.... :lol:

With 'normal' cells (i.e Nickel based), then the process is called Constant Current (CC), where the the amperage remains constant throughout the whole charge process. With a delta peak charger, the voltage rises and rises, and when it 'peaks', the charger terminates the charge.

With LiPo cells, the process is a mixture of constant current and constant voltage (CC/CV), where the amperage is constant while the voltage is brought up to 4.2v per cell, then the charger holds the pack at that voltage and lowers the amps until the pack is charged.

So:

Sub C cells (car packs)

NiCD:

- For bashing use, 3A.

- For racing use, 4-5A, 10mv cutoff.

NiMH:

- For bashing/general driving use, charge at 1C.

- For racing use, charge around 5A, no more than 10mv cutoff.

Exceptions being IB4200 cells, don't charge these above 1C.

2/3A cells (Micro packs, reciever packs)

NiMH:

- For micro packs, 1-2A, but keep a check on the temperatures.

- For reciever packs, 1C.

LiPo packs (all applications and sizes)

For all packs and applications, 1C. Double and triple check all charger settings (cell type, capacity and voltage) before starting the charge.

--------------------------------------------------------------------------

Discharging cells

In general, there is no performance benefit to discharging cells at a higher rate, only that the pack is discharged quicker. Most discharger units will discharge at 1A, some that are built into chargers can do up to 10A.

LiPo packs do not need to be discharged at all, and must never be allowed to drop below 3v per cell.

--------------------------------------------------------------------------

Summary

Make sure you check all settings before starting a charge, and with NiMH cells, keep an eye on the temps - if you can't touch the cells for longer than 10 secs, then the pack is too hot. Take it off charge and allow it to cool before recharging at a lower rate.

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  • 2 weeks later...

Another small note to add is, the higher your charge rate, the more power the batteries (or cells some refer to them as) will give to your motor, but will have a shorter run time.

If you charge your cells at a lower amperage, you wont feel the motor being quite as powerful, but the cells will last a bit longer.

If you are charging your cells at a high amperage (5A or more) I would strongly suggest you use either deans or corally type connectors, as tamiya connectors cannot carry large amounts of current very well at all.... and will more than likely melt!

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Ref Lipos, you state 1c, so to a novice, does this mean on a 3600 mah battery, you should charge at 3.6a, and should take about an hour to charge up?. My badly written charger instructions suggests charging at half c ,(trying at 1.6a, but it takes over an hour to recharge a pack, not so good on a raceday!)

amny help appreciated

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Ref Lipos, you state 1c, so to a novice, does this mean on a 3600 mah battery, you should charge at 3.6a, and should take about an hour to charge up?.

Yes :) Charging at 1.6A will take approx 2 hours, depending on how full the battery is.

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  • 2 weeks later...
  • 3 weeks later...

i dont know if this information is relevant..

But if you have a more basic NiMh charger, for example, it may have switchable charging at 1A, 2A, and 4A.

As a rule of thumb, as you cant increase/decrease in 0.1A increments, Go to the next one down from your pack rate.

For example, i charge my 4200Mah and 4500MaH packs at 4A,

But i charge my 3000MaH and 3600MaH packs at the 2A setting.

My reciever Packs are 1200MaH and 1600MaH and i charge them at 1A.

So in theory, im never going above the 1C rating.

Its good for the packs, and its good for me.. :P

Edited by TerrorTrooper
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  • 1 month later...
  • 2 weeks later...

Ok so heres a question, i have an annsman ac30 fast charger and use 3300 mAh batteries, so im gettin half and hour charge at 2.3A then it switches to a trickle, but how do i know when the battery is full? is it maths meaning half an hour at 2.3A means ive got 1.15A in my batt but i can hold 3300mAH so do i need a longer main charge? trying to get my head round this stuff!!

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It goes to trickle because it is done charging. :)

Sorry it goes to trickle after half an hour timer sorry should have made that clearer, so say 1500 batteries got warm but my 3300's dont so i was wondering how you know when all types are fully charged as im gonna get some larger cap batts, thanks

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Sorry it goes to trickle after half an hour timer sorry should have made that clearer, so say 1500 batteries got warm but my 3300's dont so i was wondering how you know when all types are fully charged as im gonna get some larger cap batts, thanks

Yeah I just had a look at the charger on fusion hobbies. It says it can only charge up too 1500mah packs. :confused:

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Yeah I just had a look at the charger on fusion hobbies. It says it can only charge up too 1500mah packs. :confused:

Oh right, ive been lookin in other places, fusion eh, thanks very much you're being most helpfull today!

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At some point this week, the guide will get updated and adjusted in line with recent tech advances. :good:

Anything you'd like to see added or clarified? Post below. :D

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At some point this week, the guide will get updated and adjusted in line with recent tech advances. :good:

Anything you'd like to see added or clarified? Post below. :D

Could sort this out......

- (E04) What is 'discharging/equalizing/cycling'?

Even if you drive your car until it stops dead, there will still be some life left inside the pack. To get this out, you need to discharge the pack. If you don't the pack won't get a fll charge the next time you charge it, and over a period of time, the pack will become useless.

All I can think of at the mo. :good:

Edited by TiM!
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