Hi All,

I have to renew my battery stock,

I have doubts between a pack made of:

1. 4+6 cells 20C – 1,240 gram
Rhino 4900mAh 4S1P 14.8v 20C http://www.hobbycity.com/hobbycity/s...0C_Lipoly_Pack
Rhino 4900mAh 6S1P 22.2v 20C http://www.hobbycity.com/hobbycity/s...0C_Lipoly_Pack

2. 4+6 cells 25c-1,226 gram.
Rhino 4900mAh 4S1P 25C http://www.hobbycity.com/hobbycity/s...5C_Lipoly_Pack
Rhino 4900mAh 6S 22.2v 25C http://www.hobbycity.com/hobbycity/s...5C_Lipoly_Pack

I would like to hear pros and cons opinions about using:
A. 4+6 cells (lighter then 5+5 cells).
B. 20C versus 25C.

Thanks in advance,
Isaac Najary

G'day Isaac,

Try the new F3A Unlimited packs. They are 1184 grams for 2 x 5S packs. Performance is great too.

Cheers
Jason.

Hi Isac,
I use the 25C 4+6 s Rhino configuration.
Two cables shortened for the serial arrangement, and four 4mm bullets soldered to them and taped together it is 1214 gr.
Performance is very good.

We don't really need more than 20C for our application. Some data shows the high C packs don't have as good cycle life.

I can charge two 5s packs on my charger but I can not charge a 6s and a 4s together.

Hi Anthony,

I allso had gut feeling that the high C packs comes at the expense of cycle life, but I am mot electronic engineer.
Can you explain that in professional way?

About the charge here is the answer from Cellpro Technical Support:

Would it be OK if you were to wire both of your packs node pigtail in series to our CPBP6P-10 node connectors? This way the charger will look at both packs as one with our connectors installed. Here is how the wiring would go using 2 of the CPBP6P-10 pigtails:

1 Black 0 Cell 1 Neg-

2 White 3.7 Cell 1 Pos+ / Cell 2 Neg-

3 White 7.4 Cell 2 Pos+ / Cell 3 Neg-

4 White 11.1 Cell 3 Pos+ / Cell 4 Neg-

5 White 14.8 Cell 4 Pos+ / Cell 5 Neg-

6 Red 18.5 Cell 5 Pos+ / Cell 6 Neg-

7 Black 18.5 Cell 5 Pos+ / Cell 6 Neg-

8 White 22.2 Cell 6 Pos+ / Cell 7 Neg-

9 White 25.9 Cell 7 Pos+ / Cell 8 Neg-

10 White 29.6 Cell 8 Pos+ / Cell 9 Neg-

11 White 33.3 Cell 9 Pos+ / Cell 10 Neg-

12 Red 37 Cell 10 Pos+

CPBP6P-10 (CH2) CPBP6P-10 (CH1)



Let me know if you have any questions, thanks.

Sincerely,

Howard G. Matos
Technical Support
301-668-4280


Best Regards,

Isaac Najary

I am not an EE either so I can't explain in a professional way. Were I make this hypothesis from is the experience of others with the TP extreme packs. Great punch but high voltage drop over the flight and short cycle life. I believe others had similar issues with other Manufacturers high c packs. Not very well documented but I think a valid point to consider.
The newer generations of high c packs may be better but not sure if the cost ($$ and weight) are worth it. Since most of our flying requirements are less than 20c and I don't have the weight budget, that is what I chose. With the cost of the Rhino packs a comparison would not be terribly expensive.

(Reviewing your post the 25C are Lighter? In that case ignore the previous comment.) [X(]

That is an interesting charging solution. If you are willing to rewire your packs then charging will be much easier and no adapters to mess with!

Actually light weight 20C and 25C packs can be made but are not the favorite of the manufacturers because there is a limited market for them (F3A mostly). They simply can't make an economical run in the 1000's of units like they can with the heavier 20C and 25C sport packs. Short cycle life issues with some of the lighter weight higher C rating packs were not the fault of the use but a fault in the design and manufacture of the batteries. In theory, a higher C pack should perform better at all throttle settings due to a lower voltage drop under load and last longer as a normal F3A flight has a rather modest average C draw on the batteries which would lead to lower temps and longer life spans which like Anthony said, it not what many were seeing in actual use.

The Power Unlimited packs for example (shameless plug) are made specifically to our 20C discharge and below 600g requirements while maintaining at least the performance and cycle life of the heavier sport packs which seem to be holding up fairly well but are very heavy. These smaller production runs are more expensive to make - hence the price difference over some of the discount sport packs. We have some 25C -5000 packs in testing (not available so please don't ask) that are the same sub 600g and a real 25C discharge rating. If they work out in our longevity tests, we will sell them but that will be months away and possibly next Spring.

I know this sounds like an advertisement but we really do spend $1,000's on testing batteries by sending sample packs to real F3A flyers who test them in real F3A setups under normal flight conditions. Honestly, we could not care less about how our batteries perform in helis or cars and don't test them that way because we are trying to maximize the packs for the typical F3A type flight usage. Some manufacturers advertise very well, and try to target all segments with their packs, then send out the packs and ask you to do the R&D for them at your expense. A high C rated battery that is also light weight with excellent performance and cycle life can be made but it will never be offered by the high volume discount houses because it is a niche product that requires special production runs and only some are willing to pay the price premium.

As an owner of all the major brands used by F3A pilots including the newer F3AUnlimited.com P.U. packs here's my thoughts (not that they're worth more than 2 cents, but just some thoughts). TrueRC, Thunder Power, Flight Power, and Zippys simply do not come close to the power of Rhinos or F3AUnlimited PUs, and the only difference between the Rhinos and the PU packs is weight and price . . . BUT . . . . and this is a huge "BUT" Rhinos have plenty of anecdotal evidence to show that a significant number of batteries arrive shorted, puffed, or otherwise unusable and getting them replaced is a major cost and hassle. If you are buying 5 sets or 10 batteries this isn't much of a problem, but if you're buying one set of 2 the risk of getting a single bad battery is HUGE, and worthy of consideration. I love my Rhino batteries, but I bought 4 and then 8 and had 2 bad batteries, one of which was not replaced because it was "lost" and I didn't pay for insurance on the return of the second battery, meaning I am out $65 + $10 + $15 on an order of 8 and one battery is unusable since it has no mate making the total loss $165. So my summary is this:



Rhino's 1 set $150 and 1233g and take a chance on quality.

P.U. 1 set $250 and 1180g and you know you'll get a decent set.


Anyways, just one dudes opinion


Joe

Joe,

Which TP? The performance difference between the PL V2 5000, PL V2 5300, and PP30C 5000 is pretty noticeable.

Regards,

Hi Dave!

My experience is with the TP PL V2 4350 and 5300s. They both hold 33 to 34 volts in flight for my Intermediate Sequence and consistently show peak RPMs around 6100 to 6200 as logged by my Castle 80HV whereas the Rhinos and PUs show a consistent 34 to 35 volts in flight and hit a peak of 6300 to 6500 RPM. I don't have any experience with the PP30C 5000s. Are they markedly different than their PL brothers?



Also . . . speaking to the original question posted, I would mention that if weight is the primary issue, one can adapt 2x5s sets to come in at close to 1200g as shown below.


Joe

Joe, be careful with those connectors. I saw what happened to a pair that got melted at the D1/D2 Shootout. To say the least, someone now has airframe repairs to contend with[&o].

Joe,

There is actually a difference between the PL 5000s and 5300s, and the at pattern power levels, the 30C 5000s are not much different than the PL 5000s for power (based on the single set of 30C packs I have), but do run 5-10F cooler.

This spring I picked up new sets (5s x 2) of:
TP ProLite V2 5000s (~1195 grams, 20C continuous),
TP ProLite V2 5300s (~1195 grams, 20C continuous),
TP ProPower 30C 5000s (~1300 grams, 30C continuous)

The V2 5000s definitely have more zip than the 5300s. I recently did some logging with the ICE 80 HV.....folllowing numbers are preflight static runup, full throttle in air prior to entering the box, full throttle just after the sequence, and postflight static runup -

5300s, flight 41
Amps - 90.0 / 83.3 / not measured / 78.5
Volts - 37.0 / 36.4 / not measured / 34.8
3880 mah used for P11 sequence (TP1010 recharged about 3500 mah)
Ending temp around 120F

5000s, flight 46
Amps - 94.7 / 89.0 / 79.4 / 80.0
Volts - 38.0 / 37.2 / 34.5 / 34.4
4860 mah used for F11 sequence (TP1010 recharged about 4300 mah)
Ending temp around 120F

Both of these sequences were big and fast in pretty strong winds, 90F ambient, and the 5000s did not dip below 36 volts until after 4000 mah was discharged. I can't explain the difference in mah between the ICE log and the TP1010 charger, but I believe the 1010 to be more accurate (it correlates pretty well with my Eagletree, which is typically a tiny bit lower for mah). And these numbers are pretty representative of other packs I have, the TP stuff is nothing if not consistent.

Regards,

Holy Batmobile Batman! What prop are you using to get those numbers Dave? Any idea on RPM?

Tom M

The max current reading logged (90 A and 94 A) exceeds the max current limit allowed by CC ICE 80HV (80 A) by more than 10%. Should the high throttle be lowered a little bit?

Limiting the throttle will not solve the problem. The readings we get on the meters are an average current. The ESC works by allowing full current to run to the motor in pulses, and throttle controls the rate of the pulses. Using the throttle to regulate the current will still let the full 94A or whatever get to the motor, just not as often.

However, if you are running 94A intermittantly, maybe it's OK for the ESC. I talked to Castle and they had me turn off my current overload protection since I fly F3A. We don't use full throttle that often, and I think the rating is max continuous current. Just double check that one as I'm fairly new at this.

Interesting.

If the measure is on the battery side, the current is DC amps and is not an average value. ESC converts the DC to AC to drive the motor, and hence the timing or frequency of the AC comes into play.

Edit. Just checked the manual for CC Phoenix HV series of ESC. There is a current-limiting feature. The default setting (normal) will allow moderate over-current condition and enters the shut-down mode after a slight-delay.

21x14 CF copy of APC 21x14E. 6500-6700 static on Neu F3A. It will scoot

With 90F ambient, motor temp (on rear windings) is typically 135-140F, and log for ESC is showing 170F (up to 180F is safe, and my cooling to the ESC could be improved in this plane).

Regards,

Dave,

That sounds like a good prop to have. Is it available to purchase? I know PT has one in this size, but not sure if yours is different.

Kevin

Exactly.....reducing the prop size is the correct way to reduce the peak current.


Yes......Castle ESCs are spec'd for continuous operation with 5 mph airflow (with exceptions for special applications), and can handle higher bursts. Burst is not specified as it can vary greatly depending on amount, duration, frequency, and cooling. Keeping an eye on ESC temps is a pretty good way to see gauge how hard the ESC is working (temps under 180F are fine).

Regards,

The specific prop I am running is not commercially available (sorry), but the only real benefit vs the APC is the reduction in weight (which is pretty substantial on the 21"+ props). I've also run the PT Models 21x14CF (available from F3A-Unlimited), and it performs very similarly.

Regards,

Dave,

Thanks. My experience is similar regarding the weight, but experiencing better power output with slight improved RPM, throttle response, and lower noise, which I believe is coming from lighter weight and firmer tip. Good to know that PT has similar performance.

Kevin

[/quote]
Dave,

Thanks. My experience is similar regarding the weight, but experiencing better power output with slight improved RPM, throttle response, and lower noise, which I believe is coming from lighter weight and firmer tip. Good to know that PT has similar performance.

Kevin
[/quote]

Kevin,

The one additional bit - as the electrics have grown in power (and RPM), APC has started to gradually "beef" up the E props (much stiffer torsionally). The 20x13E and 21x14E have been beefed, and they will turn more RPM at reduced noise levels (just as the CF props) compared to the original E prop. Throttle response is certainly better with lighter props, but that isn't really a concern (for me at least) with pattern style flying. I've also run the RASA 20.5x14 CF vs the APC 20.5x14, and they are indistinguishable (on my plane and logger), save the 1 oz weight difference.

Regards,

Dave,

Thanks. My experience is similar regarding the weight, but experiencing better power output with slight improved RPM, throttle response, and lower noise, which I believe is coming from lighter weight and firmer tip. Good to know that PT has similar performance.

Kevin
[/quote]

Kevin,

The one additional bit - as the electrics have grown in power (and RPM), APC has started to gradually ''beef'' up the E props (much stiffer torsionally). The 20x13E and 21x14E have been beefed, and they will turn more RPM at reduced noise levels (just as the CF props) compared to the original E prop. Throttle response is certainly better with lighter props, but that isn't really a concern (for me at least) with pattern style flying. I've also run the RASA 20.5x14 CF vs the APC 20.5x14, and they are indistinguishable (on my plane and logger), save the 1 oz weight difference.

Regards,
[/quote]


Dave,

Nice to know APC is also improving their E props. I have been running the RASA 20.5x14 for a while, like the performance and reduced weight, and the new 21x14 CF prop is another 10g less, at 65g. In addition, it has slight better pull compare to the RASA, not that I need it, but nice to have. I will be testing the same prop in 20.5x14 this weekend to see if it is similar to RASA, since they are the same size.

Kevin

Dave

Is the Pt 21x14 really 21 inches long? At one time I bought a PT 18x10 that was about 1/2" short.

John

Anybody knows the difference between [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXPJH8&P=7]APC NYA E prop[/link] and [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXPJH6&P=7]APC E prop[/link]?

Are both good for f3a motors?