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Old 09-14-2011, 09:00 PM   #16
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hi all
just wondering if you guys charging lipo pack @1c rate???
Im charging my 6000mah pack @8A
Do you think it is safe in long term battery life or 6A is the ideal?
cheers
Think about it this way, a battery pack only has X number of cycles it can perform in its life time. There is no way to extend this physical limit, only ways to reduce it. Now, without boring you about chemistry and physics, the relationship between total number of cycles and charge rate is exponential, not linear. So the higher rate you charge, the greater the reduction in the total number of cycles the pack can perform.

So it is ultimately a trade off, you can sacrifice some of the packs total cycles to have faster charging. Personally, i would rather have more packs and a multy port charger and get the full number of cycles out of my packs than have to buy a new pack every 6 months because i over charge.
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Old 09-14-2011, 10:02 PM   #17
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Shoot I abuse mine at 2C rate wapping 10 amps everytime I charge... I have been running GEN ACE for about a year now same pack at 2C rate no drop in performance can't beat that for a $35 pack... I stop using TP lipo which cost 3x that GEN ACE... GEN ACE is comparable with high end lipo pack without burning a hole in your pocket... For $35 I can abuse this packs and just toss it away and get a fresh one.. 
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Old 09-14-2011, 10:22 PM   #18
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HI...

A question here,

Do we need to discharge the battery before charge it to storage mode? Let say, keep it in storage mode for a week.

Coz i heard some said it is almost compulsory to discharge first before storage to maintain the power or such..
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Old 09-14-2011, 10:46 PM   #19
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No need to storage charge for that short of time.
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Old 09-15-2011, 01:24 AM   #20
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Originally Posted by K_Takuya View Post
HI...

A question here,

Do we need to discharge the battery before charge it to storage mode? Let say, keep it in storage mode for a week.

Coz i heard some said it is almost compulsory to discharge first before storage to maintain the power or such..
Just depends which brand and model charger you have.

The imax b6 and clones have a storage function where even if the pack is fully charged it will automatically discharge the pack down to the storage voltage.

Cheers
Rob.
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Old 09-15-2011, 03:44 AM   #21
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Yes, 1C charge always for me.

Good points:

1) In theory, my lipo will last longer than being charged at a higher charge rate

2) recommended safe level of charge, leading on to...

3) I don't scare the people next to me in the pits

4) Lipo performs fine @ 1C charge rate, so why go higher?

Bad points:

1) Takes longer to charge.

I can live with that...
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Old 09-15-2011, 11:08 AM   #22
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Originally Posted by tc3team View Post
Yes, 1C charge always for me.

Good points:

1) In theory, my lipo will last longer than being charged at a higher charge rate

2) recommended safe level of charge, leading on to...

3) I don't scare the people next to me in the pits

4) Lipo performs fine @ 1C charge rate, so why go higher?

Bad points:

1) Takes longer to charge.

I can live with that...
Very good advice , I am just impatient haha , wait till 0 timing comes across the north sea and then you guys will be screaming for that extra POWER !!

I will change my charging pattern because i am stepping up to modified this winter so no need for 20A charging
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Old 09-15-2011, 03:43 PM   #23
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Very good advice , I am just impatient haha , wait till 0 timing comes across the north sea and then you guys will be screaming for that extra POWER !!

I will change my charging pattern because i am stepping up to modified this winter so no need for 20A charging
Is it confirmed that charging at higher amp rate will provide a little extra punch? I thought this was just a myth....
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Old 09-15-2011, 04:40 PM   #24
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Is it confirmed that charging at higher amp rate will provide a little extra punch? I thought this was just a myth....
It is less of a myth than actual experimentation at the track.

For stock non-timing, charging the pack at higher than 1C and charging the battery warm will indeed produce more power. However, charging at more than 2C has diminishing return, that is, you get less additional power at the expense of dramatically reducing the life of battery (voltage will not hold up), plus charging the battery too warm runs the risk of puffing (once puffed, you can consider that battery gone, not safe to use anymore).

My advice for stock non-timing: Balance charge between 1C-2C with battery slightly warmer than room temperature.

My advice for super-stock or mod: Balance charge between 1C-2C but it's more important to choose higher C-rating battery than charging it with the high charge current.

I only run stock non-timing right now and I'm charging at 1.5C to both prolong the life and get additional punch from the battery. I find it the best balance of both worlds. Occasionally, when I'm in big race, I'll charge it at 2C to get more out the pack.
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Old 09-15-2011, 06:46 PM   #25
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More than 1C = being insecure, just like Tryhard ! Shouldn't it be Tryharder...ahahah....It's the Rc thread not the XXX thread !!!! Get another name J""k !!!!!!!
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Old 09-15-2011, 07:55 PM   #26
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More than 1C = being insecure, just like Tryhard ! Shouldn't it be Tryharder...ahahah....It's the Rc thread not the XXX thread !!!! Get another name J""k !!!!!!!
What are you, 10?
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Old 09-15-2011, 08:31 PM   #27
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Originally Posted by JamesL_71 View Post
What are you, 10?
IQ or age?
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Old 09-15-2011, 09:39 PM   #28
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Interesting points and post, but I would like to ask a question... What are the draw backs of not charging to 100%, pulling the LiPo after say 80% to 90%. My thought is what is the point of taking it to 100% and risking the cells expanding. I do balance every time when charging, (checkpoint inline balancer).

Is this a good or bad or does not matter practice?

Oh and at the end of the day of racing, I put them up. When I get home, I charge to 7.5V then remove and store. Is there a better practice. I know that storing them over a day at full charge is not good... Or so I have been told.
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Old 09-15-2011, 10:58 PM   #29
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Interesting points and post, but I would like to ask a question... What are the draw backs of not charging to 100%, pulling the LiPo after say 80% to 90%. My thought is what is the point of taking it to 100% and risking the cells expanding. I do balance every time when charging, (checkpoint inline balancer).

Is this a good or bad or does not matter practice?

Oh and at the end of the day of racing, I put them up. When I get home, I charge to 7.5V then remove and store. Is there a better practice. I know that storing them over a day at full charge is not good... Or so I have been told.
The drawback is the battery is not correctly cycled, this is bad for all batteries and will result in a reduction of the over all number of cycles the pack will give over its life span.

Batteries should always be charged to max voltage then only discharged to a maximum of 80%. Even better is to have the cycle to only 50% maximum discharge, this will give you more cycles from a battery before it is useless.

By only charging to 80%, you have increased the likelihood of over discharging and over discharging is bad for any batteries chemistry.

Quote:

1 C Charge 20C average Discharge, cycle life expectation: 50 Cycles to 80% Capacity. This will only affect the craziest EDF projects and must be factored in as the normal running cost of such applications.

1C Charge 10C average Discharge, cycle life expectation: 200 Cycles to 80% Capacity. This represents the limit of normal RC use and most users should regard 200 Cycles as a minimum expectation to 80% retained capacity, of course the pack will normally continue to function well beyond this point.

2.5C Charge 10C Discharge, cycle life expectation: 100 Cycles to 80% Capacity. Fast charging at 2.5C is possible with the FlightPower EVO 20 packs in exchange for a reduction in cycle life. This is recommended "in case of need" and use of a balancer is advised
This is manufacturer data on a lipo pack. Notice the two things that will reduce the overall number of cycles the pack is capable of?

1. HIGH C discharge
2. HIGH C recharge.

Last edited by RogerDaShrubber; 09-16-2011 at 12:16 AM.
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Old 09-16-2011, 02:04 AM   #30
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In another way of looking at it. it IS your money and your equipment...

But it's not only your health and safety that can be on the line.

I once charged a set of IB4200 at 6A years ago, and they went off like a shot gun. If anyone had been injured as a result of this, how would I have felt?

(Lets not get into a conversation about this part as such, yes LIPO is LIPO, Nimh is Nimh - except that the "it could have happened to anyone" line doesn't apply, it happened to me and that cannot be changed).

Yeah, I learnt from that. Treat any battery with care and charge it at the right amperage.

We are in a hobby, yes it gets serious about winning... But at the cost of someones health or safety? You have to accept there are lines you do not cross.

But if you do, it is only a matter of time before your actions can have an ending such as mine.

*safety message over, have fun with your r/c*
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