Large capacity Li-Po's versus large capacity Li-Ion airborne packs

[Hoot]

I will be assembling a 5 meter scale sailplane that will have dual airborne batteries, each about 5000Mah. I've noticed that some vendors sell's large capacity Li-po's and some sell large capacity Li-ion's.
Are there any reasons to pick one over the other ?

[Steve P]

While both can combust, LiIon pack more power. I have both in various planes and each serve their purpose.

If you are going with dual 5000’s, I wholeheartedly recommend the PowerBox PowerPak 5.0 x 2 packs. Nest of all they charge on any 12v source, even a car cigarette lighter with no special charger needed. No muss. No fuss.

PB also has an affordable replacement program when they get old. https://www.powerbox-systems.com/pro...ku-system.html.


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[ARUP]

Great visual, Steve!

[Hoot]

Steve,
Thanks for the information. Going from F3J thermal duration planes to large scale sailplanes is a bit of a learning curve. I have plenty of time to do research since my plane won't be here for about 12 weeks.

[edfmaniac]

Twin 5000's should be enough to fly that plane all week without charging. I use LiFe batts for radios and LiPo's for high current applications like motor batteries. The main advantage to LiFe is their ability to hold a peak charge or to remain at a low charge state without damaging the cells so there is less maintenance/charging/discharging. LiPo's have to be stored at a certain voltage or you are risking a shorter lifespan for the battery, but they can handle higher discharge rates. LiFe's are also lower voltage so your regulators have to do less work if you are running your system at a lower voltage than the pack's nominal rating.

[Tom]

Twin 5000's should be enough to fly that plane all week without charging. I use LiFe batts for radios and LiPo's for high current applications like motor batteries. The main advantage to LiFe is their ability to hold a peak charge or to remain at a low charge state without damaging the cells so there is less maintenance/charging/discharging. LiPo's have to be stored at a certain voltage or you are risking a shorter lifespan for the battery, but they can handle higher discharge rates. LiFe's are also lower voltage so your regulators have to do less work if you are running your system at a lower voltage than the pack's nominal rating.

Yep.......RX pack should be LiFe technology.......best of both worlds.......

[BryanB]

I prefer Lipos since I’m very familiar with them and have all the accessories to maintain them since I also fly electric models pretty regular. I’ve standardized my battery “stockpile” to simplify battery maintenance. 5000mAh LiPo batteries are cheap and has been said dual 5000’s will run a straight sailplane with all HV servo pretty much all weekend. At their price point you can very affordably have multiple sets if you are concerned about having enough mAh for an event or easily recharge them. As long as you properly store and care for your Lipos ( not used for a few days or more) they will last a few years easily. They are light, dimensionally small, have plenty of power and are relatively inexpensive. If you don’t mind caring for them they are an excellent choice in my opinion.

[lenb]

I've used both over the least bunch of years and currently use a mix of both. I was using the traditional 123 packs from NOBS batteries but the capacity is too little at 2200 -2300 Mah and with 13-19 servos in the larger planes, they was always a concern and nearly proved fatal at one point.
Large capacity is a wonderful thing,. Since you need weight in the nose anyway, you might as well carry electrons.
During my powerboat days, I used the Duraflitet Lithiuion ION batteries, those are 5800 MaH packs and work great..
Moved from those to Pulse LIPO packs at 5000 each , They've been great, have had no issues with them and they're inexpensive to buy from Help-direct. Using two in each sailplane and three in a tow plane, its common to have 7 on the flight line and 4 charging throughout a typical day. And no, you can not fly all weekend in one pack. The draw of these HV servos is quite impressive. On the tow plane, I get three hours with twin 5000 on the receiver, the ignition packs lasts forever though.
Now, Im gravitating back a little more to the powerbox distribution systems, and will be going back to the LI-Ion batteries. They're the best of all worlds as far as I have determined, but they are expensive.
My fear in Lipo packs are the same as everyone. Combustion is a real concern, so minimizing that in any way is a good thing.


That being said, I would HIGHLY recommend looking at the new Spectrums new SMART TECHNOLOGY PACKS, both LIFE and LIPO.
These packs track all your usage data in a micro chip buried in the connector. Pretty slick idea at a very affordable price.

https://www.horizonhobby.com/content...spot1_06012019

Good luck with your build

[Steve P]

Hoot — with a new Baudis build on LDS are you going HV servos? Then LiPo or Li-Ion is indeed they way to go. Not LiFe.

While LiFe is a good recommendation in many cases, and they can come off a charger up around 7.2v they function normally at just 6.6v. As many of us move to new builds, HV servos are an excellent choice. To get the most from the investment in HV servos, functioning at 7.4 volts consistently is the goal.

Many think of using regulators simply to knock down voltage in 6v systems. In the high-performance categories such as scale, jets, pattern aerobatics and such the biggest advantage of a regulator is delivery of consistent voltage to the servos meaning consistent, predictable performance of all of the surfaces as the servos always see exactly the same voltage regardless of where the LiPo or LiIon packs are between 7.4 V and 8.4 V. No peaks, no valleys, consistent behavior/performance on every flight.

[Hoot]

I'm using MKS 6130 HV on flaps, MKS 6110 HV on ailerons. two MKS HV6110'son the elevator and an MKS HV6130H on the rudder. I'm planning on using a large servo ( I don't know what brand) for the retract but will run it on its own power source.
I have a Jeti DS 24 transmitter and will be using the Jeti CB200 for power distribution, satellite receivers (2.4 and 900 MHz) and servo connections.

[BobM]

Hoot, an option for the retract instead of a third battery may be an Over Current Protector (OCP) from Emcotec. This is a user programmable unit for current limit and other options as well.

Emcotec makes these and they work very well for the retract servo. It provides protection against overload due to the retract getting jammed or other unfortunate events that would cause an increased current draw for the servo:

https://www.hacker-motor-shop.com/Ra...A16000&p=10486

The instruction manual in english can be found here:

https://www.lindinger.at/media/pdf/9...ung_V11_EN.pdf

They may be available here in the states as well from DreamWorks RC:

https://www.dreamworksrc.com

I don't know that it is an item they stock, but they are a retailer for Emcotec products and may be able to get these based on an order.

I use these on all my sailplanes that have retracts and have found they work extremely well. Mine is programmed to shut off/isolate the retract servo from the rest of the electronics system in the event the servo should be jammed or use higher current than normal for any reason. It will not allow power or signal to be sent to the servo once an over current event happens. (It can also be programmed to retry the servo after a time period, I think 5 or 10 seconds, and continue repeating this cycle instead of fully shutting off the servo)

The advantages include not having a third battery in the electronics system as well as preventing current drain on the batteries should the retract servo begin to draw more current than expected.

I use a pair of matched capacity battery packs for each my sailplanes, lithium ion packs with a capacity of at least 5000mAh.

Bob

[ARUP]

Hello, Bob! Long time no see!

[ARUP]

FWIW- I put two 5000 mAh NiMh packs in my ASW-20 which was recommended by Jeremy H of The Model Box in AL. They have 'way' more capacity than I need, hold their charge well and, since the ASW has plenty-o-room in the nose, they are great for the needed nose weight!

[RussellB]

Li-Ion and Li-Po batteries have essentially the same chemistry with the exception of a polymer electrolyte which is the Po in Li-Po. The Li-Ion cell is put in a steel can which gives it more robustness in the event of a mishap but makes it heavier for the same capacity. If you buy an assembled Li-Ion pack there is a good chance that it has built in over-voltage, under-voltage and over-current protection circuitry. In the case of the PowerBox batteries they even include the charge circuitry. With Li-Po's this protection is covered by smart chargers and auto cut-off speed controls, but being integrated into the battery pack reduces the chance for the type of errors that can cause fires.

If you are comfortable making your own battery packs you can buy 18650 Li-Ion cells and solder them up with a balance connector and have a pack that will behave like a Li-Po pack, with the exception of lower maximum charge and discharge rates. I use both Li-Po and Li-Ion in my large scale planes as well as NiMh. I am not a fan of voltage regulators so if you are going with Li-Po's or Li-Ion go with HV servos, If no HV servos, then use NiMh.