Batteries Thunder Power 2700mah 65C

[PLANETGETLOW]

I have a Hitec X2 multicharger. Curious to know what rates this battery should be maintained at (discharged, balanced, and charged)

What are you 500 size heli guys doing with your batts?

 

[Derek]

As for discharging, the only method that I use for discharging is flying. Yes, my charger has discharging capabilities but it's just quicker and more fun to just fly. For charging and balancing....each and every time that I charge a battery, it's always balanced charged. My charger does have the capabilities to Fast Charge, using only the battery plug, but I just prefer to balance charge every time.

If I'm not mistaken, this TP 2700mah 65C can be charged at a 12C charge rate, meaning that it can be charged to full in about 5 minutes. That's all fine and dandy but I'm just never in that much of a hurry. The fastest that I charge my batteries would be a 2C charge rate. I think I've done a 4C once, but mostly just a 2C charge rate is quick enough for me.

I run Glacier 6S 3300mah 45C packs in my two 500's. They are much less expensive than the TP batteries and they always come down cool.

I hope this helps!

 

[Smoggie]

FWIW here's the 'battery rules' I follow:

1. Fly with a timer so that the battery after removal from heli tests at 3.7V per cell minimum.
2. Minimise the time that the battery spends fully charged, so only charge on the day of flying.
3. Balance charge at 3C max (more often i use 2C charge)*
4. If I charge but dont use a battery I either discharge to storage or for short duration storage I seal it in a bag and put in fridge fully charged.
5. Storage voltage is anything between 3.7 and 3.9V (so as it comes off the heli is usually fine)
6. Avoid leaving battery in hot places especially when fully charged.

*Note that your charger is limited to 100W of charge power so the most you can do on that battery is a 1.5C charge, so dont worry about charging too fast.

 

[trainrider06]

I'll discharge my batteries around 1 or 2c's charging them usually around 2-3c
I wouldn't charge anything above 3c really even multiple packs I don't charge above that, I just don't trust those batteries that much, so I always monitor them closely also while charging or discharging them.

 

[Smoggie]

Usually with discharging larger batteries it's a very slow process. For instance to discharge those 2700 6S batteries at only 1C would need a charger with around 65W of discharge power.. there are very few chargers that will do that. Usually the discharge power of a charger is about 1/10th of it's charge power which is very limiting.

 

[PLANETGETLOW]

FWIW here's the 'battery rules' I follow:

1. Fly with a timer so that the battery after removal from heli tests at 3.7V per cell minimum.
2. Minimise the time that the battery spends fully charged, so only charge on the day of flying.
3. Balance charge at 3C max (more often i use 2C charge)*
4. If I charge but dont use a battery I either discharge to storage or for short duration storage I seal it in a bag and put in fridge fully charged.
5. Storage voltage is anything between 3.7 and 3.9V (so as it comes off the heli is usually fine)
6. Avoid leaving battery in hot places especially when fully charged.

*Note that your charger is limited to 100W of charge power so the most you can do on that battery is a 1.5C charge, so dont worry about charging too fast.

i assume you store them in the fridge to prevent swelling, do you always keep them in there, even if balanced?

How long do you keep them in there

I'll discharge my batteries around 1 or 2c's charging them usually around 2-3c
I wouldn't charge anything above 3c really even multiple packs I don't charge above that, I just don't trust those batteries that much, so I always monitor them closely also while charging or discharging them.

I have a HiTec X2 and it will only allow me to choose the labeled size....so 6S gets charged at 6S but i can lower the charge rate. I usually balance charge mine too

 

[Smoggie]

i assume you store them in the fridge to prevent swelling, do you always keep them in there, even if balanced?

How long do you keep them in there

Keeping them cold reduces the rate of degradation especially when charged. So generally I put them in the fridge if i have some fully charged batteries 'left over' after a flying session. If i plan on using them within a few days I'll stick them in the fridge. On the other hand if they are going to be left for longer I'll discharge them down to storage voltage. The fridge option is really just for convenience as it's easier to put them in the fridge than it is to discharge then charge them again.

I also have some batteries that are in 'long term storage' for models I rarely fly. Those are at storage voltage AND in the fridge which should in theory extend their life to the maximum possible.

 

[Tony]

6s is only the voltage. The charge rate goes off the MAH of the pack. This battery (a 2700mah pack) would have a 1c charge rate of 2.7 amps. And a 2c charge rate of 5.4 amps and so on. 6s means it has a nominal voltage of 22.2 volts. Hope this helps.

 

[murankar]

Battery care is something that is normally over looked. Smoogie listed a lot of rule of thumbs for you to follow. I can say with 100% certainty that not many chargers have a high discharge rate. I am also 100% sure the the Powerlabs PL6/8/8 Dual can discharge to a lead acid battery. This will increase your discharge rate and its normally called regenerative discharge. As for flying/using the packs for discharge is going to be the fastest way to discharge and set of packs.

Charging packs at a given C-rating is going to be a matter of preference or what your charger can handle. Most 99%-ers will not exceed 3C on charge. We simply dont have a need to fly back to back to back. If you do want to do that you can but you will need all the gear to allow for that. At which time you may find yourself charging at 4 or 5C. I do know some pilots that will charge at 5C but only if they are try to knock out a large number of flights in a short amount of time. If a pack states it can handle 5C more than likely it can but not for all the charge cycles. Stick with 3C or less and you'll be golden. One last thing, allow your packs to cool/rest between flying and charging.

One thing to be aware of is using your timer for gauging pack usage. If your doing a shload of autos then your timer is not going to mean crap. If you fly one pack hard then your flight time is going to decrease and if you fly another pack soft then your flight time is going to increase. The only thing the timer is going to do is give you a ball park. I suggest using a cell checker along with your timer. If you have telemetry then I would use that over a timer. Its going to give you live feed back about your pack, I use both a timer and telemetry alarm. My radio is also setup to call out a percentage used every 10%. So I have a callout that starts at 90% then at 80%, ect, ect, ect until I hit 20%. When I shut down the heli I am around 24% left after the pack settles down after unplugging.

Keeping your packs cold in between flights is a good practice to get into. There is one down side, you will need to let them warm up prior to charging. This helps keep the internal resistance (IR) to a minimum. Whats happening is your not allowing the pack to get warm internally while it rests between uses. This warming can increase the IRs inside the pack. In the end it will throw off your timer. As your packs age your flight times will decrease. Without a way of measuring your packs during a flight session you will never know till its to late. Keeping an eye on your max discharge will help extend your pack life. I dont know what I would do if I lost my telemetry. I rely on it for everything; headspeed, pack voltage, RX pack voltage.

 

[Smoggie]

Uri, do you have 'mAh consumed' on your telemetry, or pack voltage, or both?

I've always found pack voltage used on it's own to be a little unreliable because voltage varies so much according to load (Amps) you put on the battery and also with battery performance/age and even ambient temperature. I have to set my pack voltage alarm at a very low value so as to avoid it chirping up every time I fly hard manoeuvres, especially so with my older packs and on cold days. This low alarm threshold means that when the alarm does go 'for real' you only have seconds of battery life remaining and the battery is probably already discharged more than I'd like it to be. For this reason I use a timer as a 'first defence' and voltage telemetry only as a last ditch 'land NOW' warning.

mAh consumed may be the best option for timing flights but you need some relatively 'fancy' hardware for that. Even mAh consumed has it's limitations because it cant cover for the case of a battery developing a fault, or not being fully charged at the start of the flight, or if you fly with different size packs (though neither can a timer to be fair).

 

[murankar]

Both. I also have the ability to set up pack degradation. Even with all that I still use a cell checker to ensure I am good.

 

[Smoggie]

Both. I also have the ability to set up pack degradation.

That's the way to do it alright, very slick!

 

[murankar]

I havent set it up because its very difficult to do so. Its difficult in the sense of knowing what numbers to use. Based on your input into the radio the radio will automatically set the alarms based on the degradation of the pack, which is based of the nu,bers you supplied. Its trial and error with that.