I waant to go LiPo!

[o00scorpion00o]

Hi Guys,


I have one more question then I think I'm sorted,

I know series wiring 2 12S 8 amp lipos will give me 44 volts, So If I want 16 amps do I simply just add 1 more 12S 8 amp and wire it in parallel to the series pack and I have 16 amps? or do I need 2 in parallel, or will that give me 24 amps total capacity?


Thanks

Mark

 

[neptronix]

Hi Guys,

I have one more question then I think I'm sorted,

I know series wiring 2 12S 8 amp lipos will give me 44 volts, So If I want 16 amps do I simply just add 1 more 12S 8 amp and wire it in parallel to the series pack and I have 16 amps? or do I need 2 in parallel, or will that give me 24 amps total capacity?

Thanks

Mark

2 12s amp 8AH lipos wired in series would give you 88v 8AH.

If you want 16AH, 12S, you need 4x 6s packs, so two sets of 12S paralleled together.

 

[wesnewell]

Hi Guys,
I know series wiring 2 12S 8 amp lipos will give me 44 volts, So If I want 16 amps do I simply just add 1 more 12S 8 amp and wire it in parallel to the series pack and I have 16 amps? or do I need 2 in parallel, or will that give me 24 amps total capacity?

When you wire batteries in series you increase the the voltage. When you wire them in parallel you increase the amp hour (AH) rating, not the amps. There's lots of difference in 8 amps and 8 ah.

 

[o00scorpion00o]

Hi Guys,

I have one more question then I think I'm sorted,

I know series wiring 2 12S 8 amp lipos will give me 44 volts, So If I want 16 amps do I simply just add 1 more 12S 8 amp and wire it in parallel to the series pack and I have 16 amps? or do I need 2 in parallel, or will that give me 24 amps total capacity?

Thanks

Mark

2 12s amp 8AH lipos wired in series would give you 88v 8AH.

If you want 16AH, 12S, you need 4x 6s packs, so two sets of 12S paralleled together.

Hi neptronix,

I said 12S when I meant to say 2x 6 S, but anyways I was confusing myself lol

So Ya I got it anyway, 2x 6S for 44 volts and another 2x 6S paralleled if I want 16 amps,

I will make a good battery builder yet!


Thanks,


Mark

 

[wesnewell]

So Ya I got it anyway, 2x 6S for 44 volts and another 2x 6S paralleled if I want 16 amps,

Not quite, 16 ah, not amps. An 8000mah 12s2p pack will provide 480 amps, not 16. It provides 16 AH of power. At 16 amps it will run your motor for 1 hour. At 480 amps, your bike will burn up.

 

[Jethro56]

That would be an exciting 2 minutes though.

 

[o00scorpion00o]

I would say the motor would explode as soon as you pull the throttle

 

[Spacey]

I had my first Lipo run today, after staying up until nearly 5am.... pretty sure it was 4:40am I put 4 x 5.8ah 8 Cell 25C to 35C Turnigy Lipo on my Cannondale Gemini Downhill bike.

66V hot off the charger and 2 hours later I was off to work, man I love Lipo, I love the HS3540 rear motor and now I can totally love Lyens Sensorless Controller for it works in this motor but does not at all in the 9C 2807.

The main problem I have with the lipo is that one of the blocks has a lazy cell and also in that pack it has a cell that races far ahead of the other cells to 4.15V leaving the others at 4.05V. Balance charging again very slowly, I did also have one of the other packs very low on arrival 0.8V I think it was on one cell, that seems to be behaving better now but has 1 lazy cell.

I have ordered another long pack of 5.8ah 8Cell Turnigy to replace the bad pack but was thinking maybe I should take the packs apart and just replace the dodgy cells?

 

[Ykick]

What are you using to qualify cell voltages? RC charger? You really should double check cell voltage with another meter because I've ran into calibration issues over time with my iCharger. Had I trusted those readings I might have pushed a cell too high and another cell too low.

Luckily, I also had a cell log8 handy and when it didn't quite agree with what I saw on the iCharger - I dug out the DVM and verified that the iCharger was delivering misleading voltage readings on a cell channel or two. No big deal - I was able to calibrate and everything has been fine since.

Also, watch those balance plugs - suckers don't always deliver a good connection. Wiggle 'em with a cell log attached to qualify.

I'd try a few cycles before replacing cells - upon all the above observed, of course. Soldering cells tabs is somewhat dangerous and should not even be considered if you don't have a soldering iron up for the task.

 

[neptronix]

I had my first Lipo run today, after staying up until nearly 5am.... pretty sure it was 4:40am I put 4 x 5.8ah 8 Cell 25C to 35C Turnigy Lipo on my Cannondale Gemini Downhill bike.

66V hot off the charger and 2 hours later I was off to work, man I love Lipo, I love the HS3540 rear motor and now I can totally love Lyens Sensorless Controller for it works in this motor but does not at all in the 9C 2807.

The main problem I have with the lipo is that one of the blocks has a lazy cell and also in that pack it has a cell that races far ahead of the other cells to 4.15V leaving the others at 4.05V. Balance charging again very slowly, I did also have one of the other packs very low on arrival 0.8V I think it was on one cell, that seems to be behaving better now but has 1 lazy cell.

I have ordered another long pack of 5.8ah 8Cell Turnigy to replace the bad pack but was thinking maybe I should take the packs apart and just replace the dodgy cells?

I have one 5ah pack like that.
I'm thinking they slipped a 25C cell into the 20C pack. That cell charges quicker and discharges quicker than the others.
In a large parallel group, the effect of that cell will be muted, the larger the parallel group, but... just consider that pack a spare cells pack.. then you can use that one for surgery later when you are feeling gutsy

Always order 1 extra pack. The dud rate from hobbyking seems to be 10-15%.

 

[Spacey]

The dud cell hit 3.5v whilst the others were at 3.85v after a 12 mile ride to work.

Think I will parallel the balance leads this week, I do have 2 x Cell log 8's that I tend to belive more than my icharger.....but the dud cell charges way too quick and discharges too quick as well. I'll replace with new pack then take the dud pack apart to analyse and carefully disect.

 

[neptronix]

The dud cell hit 3.5v whilst the others were at 3.85v after a 12 mile ride to work.

Think I will parallel the balance leads this week, I do have 2 x Cell log 8's that I tend to belive more than my icharger.....but the dud cell charges way too quick and discharges too quick as well. I'll replace with new pack then take the dud pack apart to analyse and carefully disect.

Oooh. that's bad. Bad enough to leave out on it's own, unless you have like a 4x parallel pack. and use the other 3 to calm down it's enthusiastic charging/discharging.

I've thought about cutting said packs apart and using them for other stuff, if not for use as a spare cells pack.
World's largest cell phone battery? cut it up and make it into two small packs to add to your serial group? car starter? lol

I also have faith in my celllog 8s's more than the iCharger, but that's only because i screwed mine up by plugging a balance lead in the wrong order when i was a total noob

But the celllog is powered off the lipo cell itself so nothing beats a multimeter, calc.exe, and notepad.exe... fun fun!

 

[o00scorpion00o]

One more question,

If I have a 5ah lipo rated at 2C charge and I am charging 2 in parallel, does that mean I can only charge at 2 C or could I charge at 4C if they are in parallel?


Mark

 

[Spacey]

I would have thought the same rule applies in reverse, ping cells on there own would blow up with a 5 amp charge, but because they are paralleled they can take more charge

 

[Ykick]

One more question,

If I have a 5ah lipo rated at 2C charge and I am charging 2 in parallel, does that mean I can only charge at 2 C or could I charge at 4C if they are in parallel?


Mark

5Ah@2C, 10Ah@4C, 15Ah@3C, so on and so on. Parallel increasing Ah also increases C rate - under both charge and discharge conditions. Series connections are where Amps/Ah/C remain same but voltage increase.

'personally charged 15-20C 5Ah Zippy/Turnigy bricks between 2-4C and they still cooled down following a run. I suspect they can take a lot more under properly monitored conditions. nanotech Lipo sound real sexy in that regard.

 

[snellemin]

I charge my 5000mah Lipo's between 6C-8C (32A-40A) depending on my power supply. I just hate waiting on batteries to charge up at work.

 

[docnjoj]

LIpo???
Its very strange word for me....
will any body tell me about the Lipo?

Hello Morton and welcome. LiPo stands for Lithium Polymer batteries. There is a ton of material here to read if you are just starting out. Go for it!
otherDoc

 

[o00scorpion00o]

One more question,

If I have a 5ah lipo rated at 2C charge and I am charging 2 in parallel, does that mean I can only charge at 2 C or could I charge at 4C if they are in parallel?


Mark

5Ah@2C, 10Ah@4C, 15Ah@3C, so on and so on. Parallel increasing Ah also increases C rate - under both charge and discharge conditions. Series connections are where Amps/Ah/C remain same but voltage increase.

'personally charged 15-20C 5Ah Zippy/Turnigy bricks between 2-4C and they still cooled down following a run. I suspect they can take a lot more under properly monitored conditions. nanotech Lipo sound real sexy in that regard.

Thanks YKick,

That puts my mind at ease, because I was considering the Icharger 206B and some 5 amp 15C Zippy's, they are cheap and available in the German warehouse. I was looking for the 8ah Zippy's but HK are out of stock, so I might just go with 4 packs to give 10 amps, or maybe 6 to make 15, but it would have been so nice to have 4 bricks and 16 amps!

They have a 2C charge, so that means if I hook 4 of them up in parallel I can charge at 40 amps? not that the icharger is capable but It's good to know for the future, I think I will be happy enough charging @ 20 amps, beats pings 5 amps!


Mark

 

[Ykick]

You're welcome, please consider using Ah instead of amp/amps when discussing battery capacity? I kinda figured out what you were talking about and took a moment to reply but it's confusing to indicate "amps" when it's Ah.

I'm very happy with 6qty 15C 6S 5Ah Zippy bricks I've purchased over the past year. The only thing preventing a rave endorsement is longevity. I just don't have enough cycles on my 12S2P 15C Zippy packs yet to say they're good for +300 cycles.

But they remain in excellent balance with reasonable discharging - 3-4Ah per brick.

 

[o00scorpion00o]

You're welcome, please consider using Ah instead of amp/amps when discussing battery capacity? I kinda figured out what you were talking about and took a moment to reply but it's confusing to indicate "amps" when it's Ah.

I'm very happy with 6qty 15C 6S 5Ah Zippy bricks I've purchased over the past year. The only thing preventing a rave endorsement is longevity. I just don't have enough cycles on my 12S2P 15C Zippy packs yet to say they're good for +300 cycles.

But they remain in excellent balance with reasonable discharging - 3-4Ah per brick.

Yeah gotcha on the Ah,

I think I'll go for the 15C, they are plenty good enough for Ebike use! Cheap too for a 10 ah pack 123 Euros, excluding shipping of course, but at least it won't take long to ship form Germany!

Actually my Girlfriend Is home in Germany for a few days, would they allow her to take them on the plane back?

Mark

 

[Racer_X]

That' a good question, I can tell you this good luck trying to take lipos on a plane in the US.
Here in Europe they have more relaxed attitude, but it all depends on the airliner. I would check with her Airliner.

 

[Spacey]

Here is a pic of my dodgy 8S 1P 5.5ah Turnigy Lipo pack that had been balanced charged to 4.05v and then discharged at 1amp.

It had been charged to 4.15v the day before and discharged as part of a 16S 2P pack.... by the time I had got home from work the dodgy cell in this pack had hit 3.52v whilst the others were at 3.85v.

This pack had come from hobby king with the dodgy cell at 0.8v! You can see how it discharges even at just 1amp much quicker than the other cells, it also charges a lot quicker as well...time to chuck this pack.
View attachment 1

And here is the charging of that pack, you can see that the dodgy cell starts at 3.5 and then shoots up to the same voltage as the others.

 

[Spacey]

Ok so I originally ordered 4 x 5.8ah 8Cell Turnigy 25c to 35c lipo, 2 of the packs were fine with one having a couple of low cells and the last one having a cell that was 0.5v approx on delivery.

I tried to cycle that cell and bring it back to life but it always charges and discharges quicker than the others so much as to be useless. So I order another pack which arrived to day with the last cell at 1.34Volts....all the others are at 3.84Volts!

Hobby King say that they double check each pack ...my arse! I could send it back under warranty but that would mean sending it back to China rather than the German depot I bought it from grrrr.....

 

[Ypedal]

One more question,

If I have a 5ah lipo rated at 2C charge and I am charging 2 in parallel, does that mean I can only charge at 2 C or could I charge at 4C if they are in parallel?


Mark

5Ah@2C, 10Ah@4C, 15Ah@3C, so on and so on. Parallel increasing Ah also increases C rate - under both charge and discharge conditions. Series connections are where Amps/Ah/C remain same but voltage increase.
.

NO !!!!!

2C is 2C.... ie : 2 x the AH

So.. if you have a 5ah cell.. 2C = 10 amps

if you parallel 2 cells for 10ah, 2C = 20 amps..

if you parallel 3 cells for 15ah, 2C = 30 amps..

the C rate does not increase.. the AH ( capacity ) does.. and thus you can charge at a higher amp setting, but you canot increase the C rating by paralleling cells !!!!!

 

[Ykick]

Completely doofis'd that one - thanks for correction Ypedal. I thought that increasing the amount of amps you can safely draw from a pack (paralleling packs) was the same as increased C rate. My bad and I should turn in my Lipo membership.

If you want to delete my erroneous information please feel free to do so. Or, lemme know and I will delete my stupid post.

Sorry...

One more question,

If I have a 5ah lipo rated at 2C charge and I am charging 2 in parallel, does that mean I can only charge at 2 C or could I charge at 4C if they are in parallel?


Mark

5Ah@2C, 10Ah@4C, 15Ah@3C, so on and so on. Parallel increasing Ah also increases C rate - under both charge and discharge conditions. Series connections are where Amps/Ah/C remain same but voltage increase.
.

NO !!!!!

2C is 2C.... ie : 2 x the AH

So.. if you have a 5ah cell.. 2C = 10 amps

if you parallel 2 cells for 10ah, 2C = 20 amps..

if you parallel 3 cells for 15ah, 2C = 30 amps..

the C rate does not increase.. the AH ( capacity ) does.. and thus you can charge at a higher amp setting, but you canot increase the C rating by paralleling cells !!!!!