bem

My Feedback: (1)

Hi all,
My present 5 cell F3A Lipo that I have used only one season, in 2019, is getting bad voltage drops when I want power from them.
I tested them some weeks ago and when flying I get on all my 5 LiPo packs low voltage alarm on my telemetry when I add full power in vertical manouvres. I did not use the packs for 2020 season but the packs was storaged charged and stored in my garage rather cool.
I use 2x Hacker Eco-X 5S 4600 mAh F3A Competition and they are rather light, total about 960 gram for 10 cell pack.
Hacker do not have them anymore.
I found Roaring Top 5S 4500 mAh (about 465 gram for such 5 cell pack for total about 930 gram for 10 cell pack.
These:
https://roaringtop.eu/epages/69baf11...IS-25C-4500-5S
Problem is they do not have it in stock and they have not for quite some time. And they do not answer when I asked them if/when they will have it in stock.
My Galactika EP F3A model from 2017 is on the heavy side from factory so I can not really have that much heavier battery then I use.
I do not want to replace with lighter servos etc, since the Futaba servos I use are fine, I use an ESC I´m happy with and works fine (Master Mezon 130 with BEC). There is not really any cheap way to get this machine lighter so I need same weight Lipo I use and have used for many years. But I can not find it. About 960-970 gram total for 10 cell 4500-4600 mAh LiPo that works for F3A flying is what I want.
Hacker Eco-X 5S 4600 mAh F3A Competition I had bad experince with because I first had 5 packs (5 cell x 2) for just two years then they had no punch left, then bought in 2019 in june new 5 same packs but they failed all same summer with no punch left really. I heard it was bad batches made. It was rather expensive for me. Anyway if anyone knows of 5 cell 4500-4500 mAh that works for F3A use max 480 gram for a 5 cell pack I would like to know.
I have in model rather light accessories: very light wheels, Falcon carbon prop and Falcon vented carbon spinner and such. So on the model it is really not much to do to get it lighter unless I swap out servos and ESC to something lighter that I do not want to do since what I use works very nice since many years.
Thanks,
Bo

Ekvien

Hi Bo,
I have used Lipos from Joen in Denmark. The oldest pack is now 4 years old and have about 200 cycles and still working fine. (Have not used them this season because of no time for flying). A 4600 pack is about 480 gram and with shornting the cable you might reduce the weight with about 10 grams or more.

Here is a link to his shop: https://hobby4u.dk/shop/17-elektronik/283-5s-/

Flowmotion

Hello Bo,
F3alorenz has RED Power SLP
5S/4500 mAh with 490 gr. in the program. The come in weight relatively close to your requirement.
Red Power SLP
However, I can not make any statement about the quality of the batteries. If necessary, you can talk to Mr. Lorenz once.
Greetings
Gerhard

ini

About RoaringTop batts:
I have some 5S 5050 mAh 25C batteries from 2019. They are just fine after two seasons.
Pair weight is 982 g with individual EC5 connectors and 110 mm leads. Some weight could be saved by optimizing leads & connectors.

Too bad these are not in stock either.
In general these special light weight batteries seem to be inferior to good old standard ones, like Hacker TopFuel Eco-X 5000 mAh 20C (575 g each).

John F3A Junkie

What was the voltage drop at full power?

bandicootf16

I think the penalty of using light weight 4600 packs is reduced life. I have Hacker TopFuel 4500 packs with 250 cycles that are still going well. These are regularly discharged to 15 to 20% and occasionally to 10%. However they weigh 530g. There are now 5200mah options that weigh 515-530g. While it is possible to land with 25 to 30% their life is probably less than 200 cycles. All things being equal it seems that battery weight is a better indicator for life than discharge depth or capacity.

Ricardo M.

If you mean charged as fully charged that is the problem. To store Lipo, voltage has to be 3.8v per cell (storage charge).

bem

My Feedback: (1)

They where storage charged by the chargers I use, it is an option to charge to storage level, maybe it is aboyt 50-60% of capacity left then. That is not the problem, I storage charge rather often in other cases also.
But thanks for the reminder.
/Bo

bem

My Feedback: (1)

Hi there!
Unfortunately his company do not ship LiPo to my country. It was not possible to finish a buy.
Otherewise his 4600 mAh 5S Lipo would have been OK.
Regards, Bo

bem

My Feedback: (1)

Hi,
I got alarm on voltage treshold on my telemetry and I never get that with rather new packs.
I also saw the plane had weak power when I applied full power, I hade maybe flown 6-7 minutes by then.
/Bo

Ekvien

Maybe you have to contact Joen directly so he could make some arangements for sending to Sweden. It has been no problem for sending to Norway earlier or as before he took batteries with him to some Swedish Competitions like TAC and Granscupen. Anyway good luck with your search for batteries and nice to see you are back in the game.

Rgds
Espen

RuneG

I had same problem on the website Bo , contact him

Krille

Bo
I contacted Joen in february and asked about the batteries and he did not say enything about not shipping to sweden. And i vrote the e-mails in swedish so I asume he know he needed to ship them here