Which cells? IMR25? 25 or 30C?

Cheap batteries mean not as good quality control and not as tight tolerances. So your internal resistance can vary a lot from cell to cell.

We only buy LiPos from Thunderpower and we request that they come from the same batch and ir are matched as close as possible. We’ve never had issues with batteries but then again we do not run them hundreds of cycles. My personal RC LiPos also from TP are perfect after 1.5years of use, I only balance once every few charge cycles and make sure I don’t discharge beneath 3.2V.

As far as cycles on Liions. From the 25R spec sheet: “Cycle life: With standard charge and maximum continuous discharge. Capacity after 250cycles, Capacity ≥ 1,500mAh (60% of the nominal capacity at 25°C)” Sure, we do not run them at max continuous discharge but I do not see this number being any higher than 70% after 300 cycles at our discharge rates. All the info is in the datasheets, I suggest looking it up, you’ll learn more that way than asking others as there is a ton of useful information on them.

E: Cellphone batteries are lipos

Will try to look it up. Im familar with the such tests. Basically they take the maximum battery can withstand and then report the results… you should also check the charge rate, at which they charged the cells (they have it in the datasheet).

Im not sure how reliable resource batteryuniversity is but it had a similar test but it also explained that such figures (60-70% capacity left at 300 cycles) only happen when batteries are discharged deeply every cycle, with a lot of amps and then charged at almost maximum charge rate or just a pretty high one (>1C)

Your brand of Thunderpower lipos might explain why you dont witness problems some other ppl might get when buying cheaper lipo batteries. I cannot tell from memory now but the small lipo 6s battery I had was very quickly apart in voltages between cells. I think the worst were 3.5v 3.6 3.65 3.55 or so… Cannot cite that as useful information but it was way more than for li-ions which I have now.

– Anyways, you brought up a topic about li-ion and lipo lifecycle time. I think we somewhat answered that but I would still like to compile a few charts or other info, where it is said in graphs… unfortunately I don have that much time to look into that now but I know that some of this info is on battery university.

Anyways, you got a good point that with quality lipos these problems I mentioned (cell inbalance, possible lifetime decrease) are somewhat minimized or non-existant…) and with quality lipos, they might not be that far apart from li-ions in electrical durability.

All smartphone batteries are Liion!

They are Liion polymer (=Lipo AFAIK)

Yeah, that’s the reason why they puff up sometimes :smiley:

1 Like

Li-ion is a general term for at least 6-different major lithium-battery chemistries that are used for different applications (LCO, LMO, NMC, LFP, LTO, LNA). For now, it’s sufficient to know that most cell phones use the LCO chemistry (LiCoO2); because it offers the highest Wh/kg or specific-energy (some calls it gravimetric energy density).

:confused: I think this is deeper than expected… I maybe go into this a bit later on when i find some time…

@TarzanHBK Actually you brought up a good point!

I also looked into this and concluded that the chemistry is probably not the same for lipos and li-ions we use on eboards (at least in some cases)… hence this may also impact cycle life and other stats… just need to find a more detailed comparison for li ion chemistry differences… besides some of them having high discharge capability or high capacity, which I already kind of knew.

1 Like

Don’t understand your point - LiCoO2 is the chemistry used for RC Lipo batteries (and mobile phones). @PXSS is right.

1 Like

yep thats the point! We have to differ from different names, because we have different stages. Our example here:

Battery Li-Ion Lithium Polymer LiCoO2

So we often mean the same things :slight_smile:

It looks like the lipo outside structure and soft material is a bit to blame for diminished capacity in some cases… I can imagine all the vibrations etc happening, especially, if lipos are not contained and get to rattle a lot inside…

`So my options are - pay more for a LiPo, but get a higher discharge rate, but reduced performance after one year.

Or build my own Liion pack for nearly half the price, with a slightly lower discharge rate, but overall longer life from the pack before reduced performance.

Seeing as Nkon have a price break at 40 cells, looks like I’m welding together a 10s4p pack of either Samsung 25r’s, 30Q’s or LG HG4’s!

Now…which charger? :stuck_out_tongue:

Well from what @PXSS said it looks like quality lipos also work great, though they will cost more than zippys from hobbyking, i believe

I would still stick to li ions… personally

If i can i will post some more lipo/li ion soon

@Fin420 How fast do you want to charge? What’s your budget?

Will you go with bms or not? Depending on that you need to choose charger with integrated balancing (balance charger) or just almost a simple power supply unit (bulk charger) which just feeds the right voltage and amps to the bms circuit to charge batteries…

With your pack size I wouldnt choose 50-80w chargers… they will take something like 3+ hours till you will finish charging your pack…

I would agree good quality lipos work great, but in the uk my options for buying them are quite limited!

I was looking at http://alienpowersystem.com/shop/batteries/alien-10s-10000mah-35c-lipo-battery-flat-configuration/ but who knows what’s inside it, and for the same price I could build a decent sized Li-ion pack.

My lack of knowledge regarding lipos means im probably safer sticking to Li-ions considering I’m not planning to use a bms chip.

it would have to be a balanced charger @Okami I don’t want to break the bank but I also don’t want to wait a few hours for a full charge.

I would suggest to order somewhere from eu… (if you dont have to pay tax, for receiving from eu)

This way you would avoid the tax…

Im just actually having a discussion about chargers on another topic:

Anyways, the cheapest will probably be somewhere in the 20-30 Eur range + you will always need a power supply for the balance charger…

If you want to get something for the later time (for future, when your energy needs /demanded charging speed might increase) then I would suggest buying a charger in 50-70 eur range…

You would probably need some sort of ‘‘splitter’’ to split that 10s pack, into two 5s packs… After that you should still need 5A capable charger at 5s, to do the charging in 2 hours…

That would be 105w in power, so 105 x 2 = 210W charger preferably…

I would advise ''Anti matter 10A 250W charger… but the only source for it now seems to be china… which might give you awful tax, which would make the price worse… in the webshop its price is around 50usd


I actually have to run my numbers again… im not sure whenever I calculated everything ok… anyways… ‘‘general knowledge’’ of me… tells me, that for 6s ~8-10A pack, a 4-6A charger is a must… So, with you having basically 2x 5s packs at 10.000mah, you would preferably need twice as that… so about 8-10amps…

There is this nice little program called Calc RC, it has a seperate ‘‘tab’’ for charging… you can play with the numbers there:

(might be a bit glitchy and it is probably only for windows, so i hope you are not a mac user haha)

I wonder if this if possible without frying your batteries…

we discussed that method before somewhere here and it´s nothing you should do! The guy is shorting a battery and creating really bad solder spots. So just don´t do it :fire:

That’s exactly what I thought, I had all the parts handy and 10 minutes spare, so tried it out with an AA battery to see how bad it would be, it just zapped right through the nickel, and took the coating off the battery :joy:

yep! Imagine what would happenend if you not only scratch through the coating, but through the anode and damage the cell. Booof fireworks!:boom: