Battery Charge Rate Help

[th.son]

Hi,

Just picked up my Arrma Senton BLX 3S. Purchased batteries and a charger a long with it.

Having a bit of a hard time trying to figure out the best settings to charge my LiPo's at.
Battery: gensacearespammers 5300mAh 11.1V 50C 3S1P HardCase Lipo Battery 15# with Deans Plug
Charger: RDX1 Pro AC/DC Battery Charger/Discharger

The charger has profiles and a bunch of options. I currently have one programmed for charging as follows:

Battery Type	LiPo
Battery Cells	3S
Mode	Charge
C.Current	5.0
D.Current	Off
Target Volt	4.15V
Cut Volt	?

Storage Profile (need suggestions):

Battery Type	LiPo
Battery Cells	3S
Mode	Storage
C.Current	3.80v
D.Current	?
Target Volt	4.20V
Cut Volt	?

Balance Profile (need suggestions):

Battery Type	LiPo
Battery Cells	3S
Mode	Balance
C.Current	5.0
D.Current	?
Target Volt	4.15V
Cut Volt	?

Wasn't sure about Cut Volt value.
Just curious if this is a safe rate to charge this battery at? How would I know when the battery is full?

As for the storage profile. Does anyone have any suggestions about what is safe for this?

Sorry for my dumb questions, this is all new to me!

Any guidance would be much appreciated!

Cheers

 

[Primarrma]

5 amp charge will be fine I'd be happy to go up to 5.3 amps. If it's set to 3s and balanced the charger will do the rest. Just charge in a lipo safe bag. I think you can set a cut off voltage, probably per cell. If one cell is getting over charged, it will cut off and stop the charger.

 

[th.son]

5 amp charge will be fine I'd be happy to go up to 5.3 amps. If it's set to 3s and balanced the charger will do the rest. Just charge in a lipo safe bag. I think you can set a cut off voltage, probably per cell. If one cell is getting over charged, it will cut off and stop the charger.

I updated the profile to charge at 5.3 amps instead.
Is the 4.20V safe?

Are there any other values I should tweak? For either the charge or storage profiles?

 

[Primarrma]

I updated the profile to charge at 5.3 amps instead.
Is the 4.20V safe?

Are there any other values I should tweak? For either the charge or storage profiles?

4.20v is the individual cell voltage that's correct.

Storage charge is 3.80v, you can charge at a lower current, if you're not in a hurry.

 

[olds97_lss]

4.2V peak is where you want to go.
Storage for 3.8-3.83 is where you put them when your not going to use them. It's not good to store lipos for days at full charge and definitely not "empty".

Lipo's are very voltage sensitive. 3.2-4.2 is the working voltage. Although, 3.2 is pretty low, most set their LVC (low voltage cut off) to be at 3.4-3.5V.

If your charger has a cycling capability to discharge, running them down to 3.4V should be fine as it monitors each cell individually. It doesn't just drain from the main power tap like an ESC would.

I don't let mine ever sit at 4.2V or 3.5V. If I know I'm going to bash the next day, I get up early and charge. The first thing I do when I get home is put all my packs at storage voltage, even if I'm going to bash the next day. I get up early and charge them up again.

 

[Yonic]

I personally don’t charge up to 4.2 as I read it shortens the battery life. I set my charger to charge up to 4.15.

 

[Primarrma]

I personally don’t charge up to 4.2 as I read it shortens the battery life. I set my charger to charge up to 4.15.

That's interesting, how short is short I guess?

 

[Yonic]

I read somewhere (can’t remember where) that or halves the number of cycles. For what it worth..

 

[Primarrma]

I read somewhere (can’t remember where) that or halves the number of cycles. For what it worth..

If it helps why not do it, the difference in run time would be insignificant, so it wouldn't hurt the fun factor. As others have mentioned above, what about in running the batteries down, when do they recommend cutting them off for lvc. My max 6 will run batteries pretty low, so I set it to cut off at the highest setting.

 

[Lazy Bushman]

The number of amps used to to charge a battery is determined by the manufacturers recommendations. Most battery manufacturers will state a a charge rate of 2c. If you have a 5000 MaH battery then 5 amps = 1c, 10amps =2c. Basically divide your MaH by 1000 and that is 1C. All the stuff I have read says it is ok to rounded up Eg 5400 MaH @ 2c equals 10.8 amps and then round up to 11

 

[Primarrma]

The number of amps used to to charge a battery is determined by the manufacturers recommendations. Most battery manufacturers will state a a charge rate of 2c. If you have a 5000 MaH battery then 5 amps = 1c, 10amps =2c. Basically divide your MaH by 1000 and that is 1C. All the stuff I have read says it is ok to rounded up Eg 5400 MaH @ 2c equals 10.8 amps and then round up to 11

2C is max isn't it? Does it hurt to charge them at a lower current?

4.2V peak is where you want to go.
Storage for 3.8-3.83 is where you put them when your not going to use them. It's not good to store lipos for days at full charge and definitely not "empty".

Lipo's are very voltage sensitive. 3.2-4.2 is the working voltage. Although, 3.2 is pretty low, most set their LVC (low voltage cut off) to be at 3.4-3.5V.

If your charger has a cycling capability to discharge, running them down to 3.4V should be fine as it monitors each cell individually. It doesn't just drain from the main power tap like an ESC would.

I don't let mine ever sit at 4.2V or 3.5V. If I know I'm going to bash the next day, I get up early and charge. The first thing I do when I get home is put all my packs at storage voltage, even if I'm going to bash the next day. I get up early and charge them up again.

Does cycling help lipos? It seemed to be a good thing for NiMH batteries.

 

[Yonic]

Don’t cycle. Other than shorten the life of them it won’t do any good

 

[Primarrma]

The number of amps used to to charge a battery is determined by the manufacturers recommendations. Most battery manufacturers will state a a charge rate of 2c. If you have a 5000 MaH battery then 5 amps = 1c, 10amps =2c. Basically divide your MaH by 1000 and that is 1C. All the stuff I have read says it is ok to rounded up Eg 5400 MaH @ 2c equals 10.8 amps and then round up to 11

I just looked up one of my batteries( https://hobbyking.com/en_us/graphene-5000mah-6s-75c.html ), they reckon you can charge it at 5.0C, WOW! I would have been petrified to do that.

 

[slick2500]

2C is max isn't it? Does it hurt to charge them at a lower current?

Does cycling help lipos? It seemed to be a good thing for NiMH batteries.

Some batteries can do 5c.

No it doesn't, it just takes longer to charge.

Idk some guys insist that you should cycle them 3-4 times before you use them, some say to not go full throttle for the first few packs, some say just run them and don't worry about it.

 

[Primarrma]

Some batteries can do 5c.

No it doesn't, it just takes longer to charge.

Idk some guys insist that you should cycle them 3-4 times before you use them, some say to not go full throttle for the first few packs, some say just run them and don't worry about it.

Wow, if I could hold off running full throttle on any pack ever, it would be amazing.

 

[slick2500]

I just looked up one of my batteries( https://hobbyking.com/en_us/graphene-5000mah-6s-75c.html ), they reckon you can charge it at 5.0C, WOW! I would have been petrified to do that.

I charge my Turnigy HD at 2c. I can't do 3c as my charger is limited to 400w.

 

[Lazy Bushman]

Not sure about cycling batteries, I really don’t understand that. Not saying they are wrong, it just doesn’t make sense to me.

Yes you can charge lower than 2c, it will just take longer that’s all and some chargers will have a default charge time eg SkyRC chargers, that will then time out before you finish charging. I would be kinda skeptical if a battery said 5c was ok but if it was a name brand then I could be convinced.....if on a no name battery then I would cautious. @Aussie RC Playground charges his at a fairly high C rate and has a vid on YouTube where he discusses it

 

[olds97_lss]

2C is max isn't it? Does it hurt to charge them at a lower current?

Does cycling help lipos? It seemed to be a good thing for NiMH batteries.

I've read the first few cycles can be kind of flat, but otherwise, no. However, they don't like being stored at peak or low voltage. Storing at peak voltage raises the IR of the cells. Storing at empty voltage runs the risk of the cells dropping too low to be safe. So I just keep mine at storage voltage regardless what I'm doing the next day. If it was full, it's being softly drained to half (discharge at 5A). That may cut into it's overall life to do, but it's what I do anyway.

 

[Notorious J]

So is it okay to charge at 2C? Everything I've read until now, says the correct charge rate is 1C, but after reading up from different manufacturers sites, even though they recommend 1C, they also claim that you should be able to charge a well balanced battery at 2C without affecting the quality or lifespan of it. Someone please tell me which it is! I've been charging at 1C for my 5000 mAh batteries since day one, and it takes about an hour to charge. If I could be cutting that time down to 30 minutes without affecting the battery, than why wouldn't I? Fyi, they are all gensacearespammers batteries, not some cheap knock offs.

 

[olds97_lss]

So is it okay to charge at 2C? Everything I've read until now, says the correct charge rate is 1C, but after reading up from different manufacturers sites, even though they recommend 1C, they also claim that you should be able to charge a well balanced battery at 2C without affecting the quality or lifespan of it. Someone please tell me which it is! I've been charging at 1C for my 5000 mAh batteries since day one, and it takes about an hour to charge. If I could be cutting that time down to 30 minutes without affecting the battery, than why wouldn't I? Fyi, they are all gensacearespammers batteries, not some cheap knock offs.

I'm pretty sure it will shorten the lifespan some even if they are capable of being charged at a higher rate. I'm of the same mind though... if the mfr says I can charge at 2C and my charger can do it... I do. If I get a full year of use out of a set of packs, I'm happy. Considering how much I run them, if it was nitro, I'd be going through 4-6 gallons of fuel a year anyway. As it is, I've been getting 2 years out of them. That would be $280-$420 of fuel.

Will see how these HRB/hobbystar packs do compared to the SMC's.