LiPo battery care and basic information
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I would like to make a question(maybe silly for the experts here)
If I use some cells of these http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9517
probably I will also need this one http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14856
is it necessary to use a BMS or this charging board does the same job? and if I want to connect in parallel some of these packs
I suppose I must change the bullet connectors...
thanks for your answers guys!
If I use some cells of these http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9517
probably I will also need this one http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14856
is it necessary to use a BMS or this charging board does the same job? and if I want to connect in parallel some of these packs
I suppose I must change the bullet connectors...
thanks for your answers guys!
That board is no good for our use.
It may look convenient and all, however it is far, far better to make your own serial and parallel harnesses.
The output leads are very thin, so they will introduce resistance. you will need multiple ones too, and they are bulky.
These are great for paralleling balance leads: http://www.progressiverc.com/adapter-cables-and-boards/parallel-cables.html
As for the BMS, 95% of lipo users don't have any BMS. Read up as to why.. there is a lot to know. Can't be summarized in one thread..
p.s. you don't need to fork over the extra money for the 30s packs. 20C 5ah packs are rated to output 100 amps, so if you are only using a meager 5 amp hour pack, the 20C is fine.
The more packs you run in parallel, the less the C rate matters.
I have 38v 20AH consisting of 8x 20C 5ah 5S packs.. my load on them is 40 amps at most.. yet they can discharge 400 amps..
It may look convenient and all, however it is far, far better to make your own serial and parallel harnesses.
The output leads are very thin, so they will introduce resistance. you will need multiple ones too, and they are bulky.
These are great for paralleling balance leads: http://www.progressiverc.com/adapter-cables-and-boards/parallel-cables.html
As for the BMS, 95% of lipo users don't have any BMS. Read up as to why.. there is a lot to know. Can't be summarized in one thread..
p.s. you don't need to fork over the extra money for the 30s packs. 20C 5ah packs are rated to output 100 amps, so if you are only using a meager 5 amp hour pack, the 20C is fine.
The more packs you run in parallel, the less the C rate matters.
I have 38v 20AH consisting of 8x 20C 5ah 5S packs.. my load on them is 40 amps at most.. yet they can discharge 400 amps..
Damn, well if you're gonna go that big, I would recommend the zippy 20C over the turnigy 20C. They are notably more narrow, and a bit lighter. It will add up to save you some space and a pound or two overall.
Only downside is that 20C zippy has an overrated C rate, it's more like a 10C or 12C rate in real life, but on a 20AH pack it really doesn't matter.
Only downside is that 20C zippy has an overrated C rate, it's more like a 10C or 12C rate in real life, but on a 20AH pack it really doesn't matter.
Just a quick noob questions, is the LVC based on unloaded voltage? (eg without voltage sag)
The CycleAnalyst is telling me that I'm dropping below 2.7v per cell at full load, even for a freshly charged battery. I've checked that I'm not drawing too much current (max 7.5C on 20C rated batteries), so I'm wondering if the Golden Rule is based on open circuit voltage.
The CycleAnalyst is telling me that I'm dropping below 2.7v per cell at full load, even for a freshly charged battery. I've checked that I'm not drawing too much current (max 7.5C on 20C rated batteries), so I'm wondering if the Golden Rule is based on open circuit voltage.
a4178
1 mW
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- May 6, 2013
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Possible stupid question from a battery noob. Should I stay away from charging my batteries after my commute and letting them sit at 4.2V overnight for my commute in the morning? I keep reading not to store them at full charge but at nominal voltage, but does overnight count as "storage" any help is appreciated.
Ykick
1 GW
a4178 said:
I would never charge to 4.2v/cell in the first place.
But, I do charge to 4.15v/cell and leave 'em sit overnight - also 3-4 days sitting from time to time and no ill effects from what I can tell. I continue to use cells that are over 3 years old.
Ykick
1 GW
a4178 said:
Maybe pg 9 will help:
You can also use Lilo settings which are even more conservative 4.1V/cell. Be gentle, show 'em love and concern.
canadianbikeguy
1 mW
Where can I buy a high quality charger, because I plan to go RC Lipo. Either 44.4V or 55.5V, 2-3ah.
What brands are high quality, for battery, charger and controller?
Is HobbyKing any good? Was looking at their Turnigy product line.
Thanks
What brands are high quality, for battery, charger and controller?
Is HobbyKing any good? Was looking at their Turnigy product line.
Thanks
I'm about to replace a couple of my 20C Zippy LiPo packs and would like to maximise their lifespan (my old packs have suffered as my "guinnea pigs" for learning the ins and outs of LiPo). So the plan is:
- balance charge to 4.15v at 0.8C
- avoid any deep discharges to below 3.5v
- store at 3.85v (old packs have spent 99% of their life at full charge, since I wanted them to be always "ready to ride")
- perhaps even store them in the fridge! (I'd expect some strange looks from the household...)
How does that sound? Any other tips?
For maximising lifespan, is the lower the charging current the better? Or is there something like a re-invigorating current, so I should charge them at the manufacturer's rating of 1C?
Thanks,
Simon
- balance charge to 4.15v at 0.8C
- avoid any deep discharges to below 3.5v
- store at 3.85v (old packs have spent 99% of their life at full charge, since I wanted them to be always "ready to ride")
- perhaps even store them in the fridge! (I'd expect some strange looks from the household...)
How does that sound? Any other tips?
For maximising lifespan, is the lower the charging current the better? Or is there something like a re-invigorating current, so I should charge them at the manufacturer's rating of 1C?
Thanks,
Simon
DAND214
10 MW
Only tip I know from experence is, Don't Buy Zippy.
Had more disappointment with them over Turnigy.
Dan
Had more disappointment with them over Turnigy.
Dan
dogman dan
1 PW
Headwind, sounds like you have a good plan.
Cooling the packs could be a problem, unless you will warm them before charging. But yeah, if not riding for weeks, store cool and at mid charge. I store most of my lesser used packs in an old refrigerator in the yard. Not running, it at least kept the old packs I stored there all summer below 80F. Inside, the newer stuff gets to 80 in the summer. (26 C) They say never charge a frozen pack, but I don't know if they get more wear if charged when just cool. I know they waste energy warming themselves if you start the ride with a cold pack. I would expect them to like room temp better, but have no science to back that up.
Everything I have heard, implies that slow charging does less damage than fast. What's slow enough? I have no idea. But I wouldn't hesitate to charge at 1c, if I could, and was waiting to ride. My small 5 ah pack for dirt riding always gets charged at 1c, the 10 ah pack at .5c. My chargers are about 250w. But what I am trying to say, is if I could charge the large pack at 1c, I would. The tradeoff would be worth it to me. After 5 years of this, I don't like slow charging when I am ready to go, or even just waiting to return the packs to safe storage. Yes, I do miss plug in and go to sleep, with lifepo4.
I max charge to 4.15v, and don't hesitate to store overnight at that voltage, so I can ride in the morning. But I am trying to do longer storage at less, at least below 4v. If I have completely discharged, I will use the storage charge setting on my EM3ev charger.
I for sure believe that trying to keep discharges less dod helps keep them balanced. Then, a balanced pack tends to not get ruined by over discharge or over charge. I just bulk charge 14s, and monitor with the CA.
I tend to stop at close to 3.7v, but don't hesitate to go to 3.5v when I must. I top balanced my pack yesterday, after 6 months of riding. I had two of 42 cells only .05v off. The rest were less than that. The rate of discharge matters here too, the typical cruise discharge rate is 30 amps, 2c. 4c is the biggest spike I can ever see on the CA. This pack required more balancing when it was new. After about 10 cycles it really settled down. Cheap 20c zippies, new last spring. When using the old super saggy packs, I need to stop at 50v resting, (3.5v) but will see under load volts as low as 46v. It's spooky to see 46v on the CA, but seems to not do any harm as long as resting volts is above 49v. I realllllly try to never ever go below that resting. It only takes a few blocks to go from 3.4v to 2.4v. So 49v is my stop right now voltage. If I must go deeper for some reason, I pull out the cellog 8 and look at every cell before going further. No need to pedal half a mile if you are still in balance enough at the bottom.
Cooling the packs could be a problem, unless you will warm them before charging. But yeah, if not riding for weeks, store cool and at mid charge. I store most of my lesser used packs in an old refrigerator in the yard. Not running, it at least kept the old packs I stored there all summer below 80F. Inside, the newer stuff gets to 80 in the summer. (26 C) They say never charge a frozen pack, but I don't know if they get more wear if charged when just cool. I know they waste energy warming themselves if you start the ride with a cold pack. I would expect them to like room temp better, but have no science to back that up.
Everything I have heard, implies that slow charging does less damage than fast. What's slow enough? I have no idea. But I wouldn't hesitate to charge at 1c, if I could, and was waiting to ride. My small 5 ah pack for dirt riding always gets charged at 1c, the 10 ah pack at .5c. My chargers are about 250w. But what I am trying to say, is if I could charge the large pack at 1c, I would. The tradeoff would be worth it to me. After 5 years of this, I don't like slow charging when I am ready to go, or even just waiting to return the packs to safe storage. Yes, I do miss plug in and go to sleep, with lifepo4.
I max charge to 4.15v, and don't hesitate to store overnight at that voltage, so I can ride in the morning. But I am trying to do longer storage at less, at least below 4v. If I have completely discharged, I will use the storage charge setting on my EM3ev charger.
I for sure believe that trying to keep discharges less dod helps keep them balanced. Then, a balanced pack tends to not get ruined by over discharge or over charge. I just bulk charge 14s, and monitor with the CA.
I tend to stop at close to 3.7v, but don't hesitate to go to 3.5v when I must. I top balanced my pack yesterday, after 6 months of riding. I had two of 42 cells only .05v off. The rest were less than that. The rate of discharge matters here too, the typical cruise discharge rate is 30 amps, 2c. 4c is the biggest spike I can ever see on the CA. This pack required more balancing when it was new. After about 10 cycles it really settled down. Cheap 20c zippies, new last spring. When using the old super saggy packs, I need to stop at 50v resting, (3.5v) but will see under load volts as low as 46v. It's spooky to see 46v on the CA, but seems to not do any harm as long as resting volts is above 49v. I realllllly try to never ever go below that resting. It only takes a few blocks to go from 3.4v to 2.4v. So 49v is my stop right now voltage. If I must go deeper for some reason, I pull out the cellog 8 and look at every cell before going further. No need to pedal half a mile if you are still in balance enough at the bottom.
friendly1uk
1 MW
neptronix said:
Because it's a mystery lol
We should really try. It can't be that hard. I have taken particular interest in it.
If you have a stack of small packs your forever grouping up in to different configurations then a bms is a problem. They are inflexible.
If you want to charge above 10 amps the choice gets limited.
If you want a number of cells that is rarely catered for the costs can be silly.
I did hear output currant was an issue. 100 amp bikes (for instance) have very limited bms choices. However, as long as that bike has a main relay or contactor then it's fine. You would run the contactors control circuit from the bms protected supply, and run the bike straight from the battery. You would loose short circuit protection, but still have cell level lvc and safe easy charging. Your still left with the point above though, if you want an unusual cell count your buggered at any currant.
For a more typical 48v (13s) pack a $20 bms is by far the cheapest easiest safest and most professional method of getting a pack and charger combination together.
I think that's well balanced, but I also suspect I am bias. I bought rc lipo batteries and bms, plugged it all together and used it. The cells go 4.2 too 3.0 and they have done 75% of their rated life so far.
Actually It didn't go that smoothly at all, but only because I screwed up, and the bms saved me from smoke damage lol
Making my first small Lipo pack (36v/2-5S in series/zippy)....but having trouble finding a "$20 BMS"....can anyone help?
PS: puRchasing a genuine IMAX B6 charger, lipo charging sack, and low voltage monitors but,if a BMS is prudent, I will do that too.
PS: puRchasing a genuine IMAX B6 charger, lipo charging sack, and low voltage monitors but,if a BMS is prudent, I will do that too.
Hey guys, I noticed the link to a decent charger off one of the first posts on this thread is now expired. I was wondering if someone could give me a link to a charger that will charge and balance 4x 6s 5000mah 40c lipos in a decent tome frame and safely? Also I have been told that if I connect 4 of t hese batteries together im going to get a bigger spark each time one is connected. Is this true? As all 4 of these will be running at one time to power a magic pie 3 in a drift trike. An rc hobby shop told me connecring the first one to the motor their will be a small spark but he would be worried about damaging the batteries and my safety every battery after that. Can someone please give me some advice or who I should be speaking to about this? Please feel free to email me as I wont receive notifications if you reply to me on here. Mh email is juddkiley@gmail.com. thanks in advance!!
BikeFanatic
1 kW
Here is a RC charger that I use, so I can recommend it. It will charge two at once but you will need to purchase a powerful power supply to power this charger I will link to both.Not cheap but good especially for newbie.
http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=20613
Here is a power supply with this one you could charge each six series battery at 5-7 amps each.
http://www.hobbyking.com/hobbyking/store/__17754__HobbyKing_540w_100_120v_Power_Supply_13_8v_18v_30amp_.html
http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=20613
Here is a power supply with this one you could charge each six series battery at 5-7 amps each.
http://www.hobbyking.com/hobbyking/store/__17754__HobbyKing_540w_100_120v_Power_Supply_13_8v_18v_30amp_.html
Thanks heaps mate, and that charger is definitely cheaper than the ones iv been looking at. Has it ever had any problems or not balanced your batteries properly? And are you using yours in an rc or a e-bike? Id very much like some more info if its used in a bike and what specs and hub motor your using. Thanks heaps.BikeFanatic said:
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