Winmax 50-100c Lipos vs Hyperion 45-90c . Battery testing Review.

[Drax21]

Winmax

Power was great once again. I kept the throttle on full.
Top speed was 45.1MPH (nearly the same as Hyperion)

These batteries suffered an even higher voltage drop and only lasted just over 4mins (8400mah in 4mins at 50c) which shocked me.
Once again my lipo protector did go off but by that time the cells just like the Hyperions had dropped just below 3v.

I usually run these packs in parallel for about 8 mins and bring the cells back at 3.3V but something is up.

Both the packs swelled a little and were quite warm at 34c. (The esc and motor were both cool)
I have also been able to bring them up to storage value but in this unexpected circumstance they did not handle the extreme drop in voltage as good as the hyperions did.

[Chrisg81983]

Tim What is the complete setup motor esc prop and so on the more details the better we can help

[Krusher]

3.4V/cell seems reasonable; my surfing last night revealed that most with 50C+ batteries don't use the old 3.0 standard and some even use as high as 3.7V/cell at a reduced capacity of course. This makes sense as better cells have lower internal resistance and don't need to be discharged as deep.

Regarding your recent problems, are you charging them in pairs or individually? I'm curious if charged individually if they are still taking the same charge. Also are your individual cell resistances still the same?

I have my connectors soldered on now and should get my charger back late next week.

[Drax21]

Tim What is the complete setup motor esc prop and so on the more details the better we can help

Hi Chris, It's Exactly the same as when I started the thread

Castle Creation 1515 2200kv (Had about 25 runs never hot)
Seaking 180a ESC (LVC disabled due to malfunction) (Ran 10 times max)
Octura M445 Balanced and Sharpened

[Drax21]

3.4V/cell seems reasonable; my surfing last night revealed that most with 50C+ batteries don't use the old 3.0 standard and some even use as high as 3.7V/cell at a reduced capacity of course. This makes sense as better cells have lower internal resistance and don't need to be discharged as deep.

Regarding your recent problems, are you charging them in pairs or individually? I'm curious if charged individually if they are still taking the same charge. Also are your individual cell resistances still the same?

I have my connectors soldered on now and should get my charger back late next week.

I always charge them individually using a 206b Icharger. Will charge them up fully before next weekend and let you know if the balance correctly. The resistance in any of the cells has not risen according to my charger. The Winmax batteries remain extremely low in resistance compared to most other batteries.

[Krusher]

Well, nothing seems to be out of the ordinary as you describe it. But I have some thoughts on it.

I have a Cellpro 10S by the way, which has been superseded by the 10XP. It's on another forum where I read some people are stopping their batteries at 3.7V/cell. According to the guy who develops the tables for the Cellpro, 3.7V is 20%, +/- depending on your C rating.

The lower the internal resistance of the cell, the easier it is to reach 0% with a higher cutoff voltage. When that happens, the voltage falls off like a rock. That's what it seems like is happening to you.

i.e. in an ideal battery, there would be zero cell resistance. The battery would slowly discharge with zero heat generated, and when the cell hits 0%, the voltage would hit zero instantly.

Knowing this now, I would not discharge those Winmax lipo's below 3.6V if you can adjust your cutoff. I have some old lipos that puff every time. Their internal cell resistance isn't that great, and they have a low C rating. So I have to set my cutoff low because the voltage drop in the actual cells and 12 AWG output wiring is much higher.

Let me know if this makes sense or not...

My boat is a Supervee 27; heavily modified. :) I get 38MPH last time I checked it--getting a little unstable now.

Neu motor 1415/2Y (1100kV)
Seaking 120A ESC
Prather S225
6S LiPo

EDIT: I looked up the manual for my ESC and discovered that the highest voltage cutoff I can set is 3.4V/cell. It will be interesting to see what your experiments come up with.

[Drax21]

I think I have figured out the problem. The motor is drawing more amps than it was before. So it's become inefficient. I'm pretty sure of this as the wires running to the batteries are fine.

I say this because of the wires that join the esc to the motor have partly de-soldered and they haven't budged before in over 10 runs.
DSC_2514.jpgDSC_2515.jpgDSC_2516.jpgDSC_2517.jpg

What do you guys think?

[martin]

Did this problem stem from previously using the m645 prop, thats a big prop ecspecialy if you were on & off the throttle when you used the 645 previously.

[Drax21]

Did this problem stem from previously using the m645 prop, thats a big prop ecspecialy if you were on & off the throttle when you used the 645 previously.

I not sure really. The motor could of been fairly hot after last time but I am unsure. All I know is that the motor was touchable after it took 20mins to float back to me but could have reached temps of around 35c when the wires on thee eagletree de-soldered

[Krusher]

If you had good water flow the whole time, maybe you have a motor failure of some sort. For it to go from mildly warm to untouchable after a 20 minute cool down seems that way. It could also be the ESC is bad and that overheated the motor.

I looked up the melting point of solder, and if you used 63/37 solder you had to hit at least 182C and it's even higher for 60/40 solder.

By the way, if a motor gets too hot, the heat will permanently destroy the magnets which kills the motor. Your motor should have a 60% of list price rebuild cost (older motor) or a 50% of list price (newer motor). I know this because I had my 1415/1.5Y rebuilt for a 1415/2Y.

[Drax21]

If you had good water flow the whole time, maybe you have a motor failure of some sort. For it to go from mildly warm to untouchable after a 20 minute cool down seems that way. It could also be the ESC is bad and that overheated the motor.

I looked up the melting point of solder, and if you used 63/37 solder you had to hit at least 182C and it's even higher for 60/40 solder.

By the way, if a motor gets too hot, the heat will permanently destroy the magnets which kills the motor. Your motor should have a 60% of list price rebuild cost (older motor) or a 50% of list price (newer motor). I know this because I had my 1415/1.5Y rebuilt for a 1415/2Y.

Yeah water flow was good as I could see it pouring out the back. I am currently using Multicore silver solder (lead free). melting point is 217c!
Would it be cheaper to have it rebuilt or just buy another motor like a Leopard 4082 instead? I'm not even sure if the motor is dead really as the last vid on this thread shows when I brought it in and the motor was completely cool. The only time it may have got hot was 2 runs before the last when I ran the M645.

I have just re-soldered all the esc wires so I will run for a short time next weekend and see how it goes.

[Krusher]

If you're still getting the speed you expected then the motor is fine. My motor was involved with three separate problems (overheat, underwater, and an ESC fire) so I rebuilt it as a precaution. Well, that and to lower the Kv rating a bit.

Ya melting a 217C connection is pretty amazing. Once you get it soldered back up again you should be able to determine what is bad.

I was looking at those Leopard motors too last night just for curiosity sake. The 4082 is a 2kW motor, quite a bit more than your 1250W. It weighs more too; so before going that route someday I'd check your Eagle Tree results and see how many watts you're really using. Although I'd admit a huge motor does have a coolness factor lol.

[Drax21]

If you're still getting the speed you expected then the motor is fine. My motor was involved with three separate problems (overheat, underwater, and an ESC fire) so I rebuilt it as a precaution. Well, that and to lower the Kv rating a bit.

Ya melting a 217C connection is pretty amazing. Once you get it soldered back up again you should be able to determine what is bad.

I was looking at those Leopard motors too last night just for curiosity sake. The 4082 is a 2kW motor, quite a bit more than your 1250W. It weighs more too; so before going that route someday I'd check your Eagle Tree results and see how many watts you're really using. Although I'd admit a huge motor does have a coolness factor lol.

Yeah I was looking at my CC1515 earlier and I thought..."It looks a bit small" I will def have a look at my ET data.

[Chrisg81983]

Tim I got your pm do you have any eagle tree data you can post for us to see

[Drax21]

Tim I got your pm do you have any eagle tree data you can post for us to see

Not from the last runs as I left the ET system at home but I do have a graph of the Watts on the previous Winmax Lipo run

here Winmax Watts.jpg