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simalarion

NimH Charge School

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Newbie .. 

Ended up buying SkyRC mini B6 including Adapter after trying to learn Basic charging  and battery types on this forum. There is stil a few things can not understand, even after watching Youtube vidoes & reading on this forum.

1. First off all how to i check the actuall capacity of the NimH battery?, can i see the actual mAh when charging on lets say safe setting 1 A, and how do i see it ?.

2. If i am to charge 5000mAh 6-Cell 7.2v - is the setting 5 v and then 6s ? (most of the vidoes are a bit unclear and most is about LiPo on this).

3. Will this charger warn me if any settings are wrong?

4. Discharge - Balance. I found out you should not Discharge NimH battery 100%, was is the setting i should use on this SkyRC charger? (very many similar charger to SkyRC and all with the same menu). Balance i did not quite get, how is this working?.

I will continiue to use NimH batteries untill i know more as i understand you need to be more carefull with LiPo, so for now i will stick to learing about NimH. 

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I don't know enough about how that SkyRC charger works (check the manual). But it should have a NiMH mode.

Very important - a NiMH is NOT a 6s LiPo!!! It's not a LiPo at all. So those settings should never be used on a NiMH. Totally different charge algorithms.

You can't balance a NiMH (not with a balance cable anyway).

No, they don't like a full discharge to 0V. But most NiMH chargers wont let you do that anyway, and will cut off at around 0.9V per cell. 

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The nihm batteries that I use are 3300mAh and I set my charger at 3A, with the lipo's are 2s 5000mAh and I set them at 5A

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If it's anything like the charger I have, I used to just set it to nimh mode and set it to 7.2v then it did it all itself, as it cannot balance that type of battery. The only setting after that was amps so I just set it to 3amp as i used to use 3300 nimhs. The only thing that was never known was how charged the battery was, all it showed on the screen was how much capacity was put into the battery ( basically if it stopped charging at 1650ma, that was just what it needed to top the battery back up, so it would have already had half charge in it ) 

Lipo mode is completely different, it really should be balance charged, I would hope that the screen would show what each cell has and may just show the total volts that it is charging to, rather than the amps per cell, which if it's a 7.4v 2s then that has to be the setting used, mine shows it as 3.7v per cell as its charging.

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1 hour ago, DayRider said:

The nihm batteries that I use are 3300mAh and I set my charger at 3A, with the lipo's are 2s 5000mAh and I set them at 5A

In Manual i could only find howto on LIPo battery. 

 

How to i best check if the NimH is actually 5000mAh?. one suggestion i found was to charge it safe and see how high it charge?.

 

Here is the NimH charge modes from manual:

image.png.fd99b20306b20f5925f196d3d83cd6f3.png

 

That Cycle progam seems usefull ?

 

 

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I would be tempted to start with the auto charge mode but keep an eye on it to see if it does anything unexpected. 

If the NiMH says 5000mAh on the label, then you have to assume it is 5000mAh. It probably has less actual capacity, but that is what it is rated at.

Cycle mode can often fail if the battery doesn't charge properly on one of the cycles. I always check the battery before discharging.

Basically, if a NiMH is warm after a fast charge - it's charged. If it's cold - it isn't.

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I have an IMAX B6 charger which is older but should be very similar to yours.

You can use the Charge or Auto CHG mode of the charger. I use the charge mode at mine. But you should set a max current for charging in auto mode.

I always charge my batteries  with 1C. This means if you have a 5000 mAh battery you charge it with 5.0 A, a 3500 mAh for example with 3.5 A. When the battery is fully charged you can see  the charging time and the capacity on the display. 

Of course it is possible to cycle your battery to evaluate the capacity of the battery but this something which is normally done to refresh old batteries.

After some cycles of standard charging you will know the capacity of the battery as well.

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6 minutes ago, sosidge said:

I would be tempted to start with the auto charge mode but keep an eye on it to see if it does anything unexpected. 

If the NiMH says 5000mAh on the label, then you have to assume it is 5000mAh. It probably has less actual capacity, but that is what it is rated at.

Cycle mode can often fail if the battery doesn't charge properly on one of the cycles. I always check the battery before discharging.

Basically, if a NiMH is warm after a fast charge - it's charged. If it's cold - it isn't.

Thanks.

So you would not suggest that the first thing i do when i get  a proper charger like this to run the Cycle program you would start with Auto to see what setting it lands on?, sounds logical i did not know it had a Auto program from the youtube videos i saw. 

 

I have ordered it today so i do not expect to have it before 2-3 weeks, but it does not hurt to learn the Basics around charging before i start :)

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2 minutes ago, Aerobert said:

I have an IMAX B6 charger which is older but should be very similar to yours.

You can use the Charge or Auto CHG mode of the charger. I use the charge mode at mine. But you should set a max current for charging in auto mode.

I always charge my batteries  with 1C. This means if you have a 5000 mAh battery you charge it with 5.0 A, a 3500 mAh for example with 3.5 A. When the battery is fully charged you can see  the charging time and the capacity on the display. 

Of course it is possible to cycle your battery to evaluate the capacity of the battery but this something which is normally done to refresh old batteries.

After some cycles of standard charging you will know the capacity of the battery as well.

That was useull info, thanks.

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13 hours ago, DayRider said:

Up load a picture so I can see your charger mate.

As i wrote: I have ordered it today so i do not expect to have it before 2-3 weeks, but it does not hurt to learn the Basics around charging before i start :)

But it is this one:

 

 

image.png

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4 hours ago, simalarion said:

As i wrote: I have ordered it today so i do not expect to have it before 2-3 weeks, but it does not hurt to learn the Basics around charging before i start :)

But it is this one:

 

 

image.png

Right it's the same as my set up the 1st button selects the what program, press that till you get what you need then press the 4th button (start) then press it again that amps will stay to flash, use the arrow buttons to select amps then enter untill it starts but it will prompt you  give me a shout if you have any problems mate

Button 1 select program

Button 2 3 changes value

Button 4 is enter and go

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