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Electric Guide


Garry

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Hi guys,

Just wondering....

I've started charing my first LiPO pack and entered all the propmts correctly (4000mAh pack, charing 4A, 2s so 7.4v entered).

I'm just a little confused over the amperage rating dropping steadily huh.gif . It started at 4A and held it for about 6 minutes before it slowly started dropping. After 33 minutes the charge rating is now 1.65A.....

I'm thinking that LiPOs (obviously) are charged differently to NiMH's, so is this steady reduction of charge rate due to the battery type?

Cheers.

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Hi all,

I have a ansmann powerjack gp pro charger.

I am trying to work out the charge time for my hump pack, the charger charges at 11.2 V, 200 mA.

My hump pack is 1500 mah so how long/ how do I work out how long it will take to charge.

Many Thanks in Advance,

Adam.

1500(mAh) divided by 200(mA) = 7.5(hours)

:good:

Hi guys,

Just wondering....

I've started charing my first LiPO pack and entered all the propmts correctly (4000mAh pack, charing 4A, 2s so 7.4v entered).

I'm just a little confused over the amperage rating dropping steadily huh.gif . It started at 4A and held it for about 6 minutes before it slowly started dropping. After 33 minutes the charge rating is now 1.65A.....

I'm thinking that LiPOs (obviously) are charged differently to NiMH's, so is this steady reduction of charge rate due to the battery type?

Cheers.

Yep, it's the way LiPos charge. The charge rate will keep dropping until they are fully charged.

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  • 5 weeks later...

What do you mean by pairing up? Its just a case of wiring them up according to the supplied instructions, and you're done.

any motor with any ESC? what are if any the restrictions?

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Ahh, okies.

Sensorless ESC with sensored and sensorless motors (but sensored motors won't run that smoothly).

Sensored ESC with sensored motors only.

Stick to turn limits if reccomended by the ESC, stick to KV limits if reccomended by the ESC, but don't mix and match KV rated motors with motors listed with turns, as they aren't 100% directly compatible.

And stay with the same size supplied motor or smaller (so a System supplied with a 540-sized motor should in theory run smaller 380-sized motors, but not 550/600-sized motors, if you stick to the KV/Turn rating again).

Those are safe limits, some ESCs can run harder with different software but not all, so better to be safe than sorry. :good:

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  • 3 weeks later...
  • 3 months later...

Hi All,

The question I'm about to ask is probably so incredibly noob-ish you are all going to hate me laugh.gif

The battery in my Micro- T is 150mah so to charge at 1C I would have to charge at 0.1A correct?

The wall charger I have has a variable rate of charge as follows: 50mA/ 80mA/ 120mA/ 180mA/ 240mA and 300mA.

So to charge at 1C (0.1A) Which setting should I opt for?

Also how many mA are there in 1A?

(For future reference)

Many Thanks in Advance,

Adam.

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I charge mine at 0.2A. :whistling:

My brother is even worse though, he has no patience so charges at 0.3A. :lol: It does not get too hot, but it can't be good for the life of the pack. Out of those I would use 120mA

Cheers :]

Also the chargers instructions says that to work out time you have to use the equation: Battery Capacity x 1.4/ mA Charge Rate

I thought that it should be Battery Capacity/ mA Charge Rate?

Which equation should I use?

Thanks,

Adam.

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  • 3 months later...

I'm working on some motors at the moment and made a handy chart, although there is no 'true' conversion here's a good idea for those wondering.

Remember, KV is not a measurment of power but RPM per volt. Brushless motors should be rated in KV ideally but for racers and gearing, turns seems a little more logical.

med_gallery_267_10_3614.png

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If a 3.5T brushless 540 motor is doing 10500 RPM/volt.....running that a 3S....11.1V .... that would mean the motor would spin up to 116550Rpm....which is nearly 2000 rotations per second.

If that's reading it right...that's insane! No wonder they make our cars go fast :)

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If a 3.5T brushless 540 motor is doing 10500 RPM/volt.....running that a 3S....11.1V .... that would mean the motor would spin up to 116550Rpm....which is nearly 2000 rotations per second.

If that's reading it right...that's insane! No wonder they make our cars go fast :)

And very inefficent. :lol: You shouldn't really be running 3.5t on anything more than 3s anyway.

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Just tried the salt water thing. Left it for well over a week in water that was so full of slat it wasn't dissolving it any more and there's no sign of the tabs inside corroding. Removed them myself when I took the pack apart to see if it had worked.

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It could be possible that the pack has silver tabs rather than aluminium? I wouldn't have thought that was likely with LiPo but you could buy silver battery bars for assembling NiMH packs.

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  • 2 weeks later...
  • 2 months later...

Fantastic guide.

I have NiMh, stick packs (1800 and 4600), AA's, a receiver pack and a glow starter, and am soon upgrading to Lipos. I had no idea what I was doing and was thinking how best to ask what I needed to do (already have an Imax B6 charger).

I now know what current to charge at for all of my NiMh's and what to do with my lipos when i receive them, could not have asked for better.

Thanks lads. :good:

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  • 2 months later...

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