Combining 3 LiPo batteries?

Marv1337n

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Joined
Jul 7, 2018
Messages
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Location
Germany
Hello

I'm currently thinking about replacing my 48V 13,6Ah 18650 battery with a 66,6V 20Ah LiPo battery.
I wanted to use 3 of these: https://hobbyking.com/de_de/multistar-high-capacity-20000mah-6s-10c-multi-rotor-lipo-pack-w-xt90.html
Now the question arises how to connect them in series and how to charge 3 of them?

Thanks for your help
 
`Kay. I'll bite. :mrgreen:

Wanna "play with fire"? Hehe... Lots of info on the `Sphere re LiPo... like:

LiPo battery caught fire during charging:
https://endless-sphere.com/forums/viewtopic.php?f=14&t=95562

Includes:
Search found 213 matches: "Lead-acid" fire
Search found 182 matches: cobalt fire
Search found 1327 matches: LiFePO4 fire
Search found 5610 matches: lipo fire

So. Lovely (light weight, high energy density per pound, etc) but yah gotta handle extra carefully. Like many/most folks, I'm too lazy. :lol:
 
LockH said:
`Kay. I'll bite. :mrgreen:

Wanna "play with fire"? Hehe... Lots of info on the `Sphere re LiPo... like:

LiPo battery caught fire during charging:
https://endless-sphere.com/forums/viewtopic.php?f=14&t=95562

Includes:
Search found 213 matches: "Lead-acid" fire
Search found 182 matches: cobalt fire
Search found 1327 matches: LiFePO4 fire
Search found 5610 matches: lipo fire

So. Lovely (light weight, high energy density per pound, etc) but yah gotta handle extra carefully. Like many/most folks, I'm too lazy. :lol:

If they were so highly unsafe they wouldn't be legal anymore so well everybody can have bad luck, even with 18650. The thing is a compareable 18650 battery is like 3x that price and has much smaller discharge ratings. Please stay on topic I know that they aren't the saftest batteries.
 
I have used Multistars for over 3 years and as long as you charge to 4.1v that leaves a bit of headroom in case of imbalance and also gives you a much longer lifespan (still on my original batteries).
Dont discharge below 3.6V and they will rarely go out of balance.
I always check for balance before and after each ride and bulk charge with Meanwell NES power supplies.
I do keep them in a cow byre though so even if something went wrong it wouldnt cause a major problem.
 
Marv1337n said:
If they were so highly unsafe they wouldn't be legal anymore so well everybody can have bad luck, even with 18650. The thing is a compareable 18650 battery is like 3x that price and has much smaller discharge ratings. Please stay on topic I know that they aren't the saftest batteries.

Hehe... They're "safe" `cause LiPo cells and pouches are sold to install in toy models... "NOT for "human consumption"". :wink:

"Please stay on topic"... Hehe... Where safety is not a concern. :wink:
 
I wonder if it has anything to do with the fact that any and every time someone says "LiPo" someone invariably responds with "FIRE!"
 
dustNbone said:
I wonder if it has anything to do with the fact that any and every time someone says "LiPo" someone invariably responds with "FIRE!"
Hehe...
Search found 213 matches: "Lead-acid" fire
Search found 182 matches: cobalt fire
Search found 1327 matches: LiFePO4 fire
Search found 5610 matches: lipo fire

Perhaps `cause it's a lot of energy, watt gets released all at once... too frequently? Lots of newbs playing with bettery-electric traction, watt can fail in "spectacular" mode. :wink:
 
FWIW, it was "Safe" lithium that burned my house down. On the flip side, I never trusted my lipos enough to charge them in the garage. Outside, or inside my fireplace for those. From now on, it ALL charges outside, and stores outside in the fire damaged kitchen stove.

There is a sticky thread in the battery section for lipo how to. https://endless-sphere.com/forums/viewtopic.php?f=14&t=26621 Many ways to arrange the wiring. I eventually settled into using them in 14s (52v) 10 ah chunks, using two series connected 5 ah sections that were then paralleled for 10 ah. Charging I did with a regular bulk charger, that I set to charge the whole thing to 4.15v per cell. Slightly undercharging allowed me to run them more out of balance safely.


The other approach is multiple RC chargers. Each section being 6s, 8s, or whatever. Then when each chunk is balance charged, you then do series connections to run them at 60v or whatever.
 
I will help answer your charge question , before that respond to the lipo safe tpic .
( I used to be against Lipo's ) ...
Until I saw youtube videos of the , so called safer 18650 battery packs catching fire .
So
I take the following precautions
1) Build a Battery Bunker , with concrete retaining wall blocks and large paver blocks.
or
You can get a free old BBQ from someone who bought a new one.
or
Like DogmanDan , get a used free old oven that someone puts out on the sidewalk with free sign on it, same with a old BBQ
2) I charge outside, if inside I bring a few large paver blocks and a retaining wall block and set it right next to the back door. I also have some welder gloves near by.
3) When a charger charges up to 4.2 volts per cell I turn off the charger, the packs then settles down to about 4.15 volts per cell, and then go on a ride .
People too often just let the charger charge for longer than they need, it is good for balancing the pack to the higher 4.2 volts per cell, but by watching for a few times how long it takes for a battery charger start to lower its charge current ( Amps ) you can then tell about how long a charge to just get it to that 4.2 so that it settles down to about 4.15.
4) I use a timer ( alarm clock on your older cell phone works perfect )
That way I then charge battery # 2, and # 3 , and so on the same amount of time.

Now for a charger, you want the largest wattage and amperage charger you can get , especially for a large battery like a 20,000 mAh pack.

The new charger that is getting rave/good reviews is the iSDT series, for you with only 6 cells in series you can get the iSDT T6 , which is a little cheaper than the iSDT T8

You are also going to want a moderate to high wattage power supply , 500 watt or 750 watt or 1,000 watt . Mean Well or Surplus , Modified HP Server Power Supply.

When it comes to a item like a charger ( and the charge cords and/or connectors for making my own charge and input cords ) I trust the business I can call on the phone and get advice from people who really use RC products.
Here is a Short List

Aloft Hobbies

Progressive RC

Buddy RC

They also tend to sell the latest , newer software fixed versions of chargers .




Marv1337n said:
Hello

I'm currently thinking about replacing my 48V 13,6Ah 18650 battery with a 66,6V 20Ah LiPo battery.
I wanted to use 3 of these: https://hobbyking.com/de_de/multistar-high-capacity-20000mah-6s-10c-multi-rotor-lipo-pack-w-xt90.html
Now the question arises how to connect them in series and how to charge 3 of them?

Thanks for your help
 
Get three cell monitors. Only hookup in when checking lvc and end of charge. Yes each and every time. You are now the human bms. Even when charging I don't leave the meters plugged in .Just to check. Yes you should have a balance charger as is an ez way to first balance charge before connecting in series. You can get the una6 with battery nanner that can charge 8 packs one at a time must buy battery nanny at same time..
 
10-20% of the HobbyKing LiPo's were faulty upon delivery when tested, this was a couple years ago.
Search ICECUBE57 he did a lot of good research on them!

edit
Here is the link with the correct #'s which was 10-15%
https://endless-sphere.com/forums/viewtopic.php?f=14&t=61672&p=1173758&hilit=multistar+rate#p1173758
Expect as much as 10-15% dud rate. But when you do get good ones they are golden.
 
If you do get a faulty one, send it back right away and keep contacting them about it. H.K. is a company you have to chat/email with several times to get something resolved.
I have gotten lucky with my Lipo's a few of them looked faulty, but when they were checked by someone who knows about how to check them , they were within limits.
With H.K. Lipo's you might have to do up to 6 or more charge / discharge cycles for them to balance out near each other. The one battery I thought was faulty turned out to be fine once I did this.
Note: I consider H.K. Lipo's , something I have to keep a close eye on with charging , discharging , and storing .
 
I only found the una9 balance charger with battery nanny $ 99.00 Balance charge up to 8a thru the sense wires per cell if needed. And if you wires to support 8a.
 
999zip999 said:
I only found the una9 balance charger with battery nanny $ 99.00 Balance charge up to 8a thru the sense wires per cell if needed. And if you wires to support 8a.

That's exactly what I want but I read on the specs this:
One of the great features of UN-A9 Plus is that you can charge multiple batteries at once. You can either charge
1 x 6-Cell Battery
2 x 4-Cell Battery
3 x 3-Cell Battery
4 x 2-Cell Battery

So that doesn't really work for my setup, right? 3x 6-Cells
 
The battery nanny . The battery nanny. Can charge 8- 6s . I couldn't move the link but it's the charger the power supply and the b. But like my Ridgid tool battery charger that charges two batteries but only one at a time. Una9 plus +.
 
https://www.hobbywow.com/en-the-latest-version-una9-plus-lithium-balance-charger-with-adapter-plate-and-filled-with-discharge-p240990.htm

https://www.fpvmodel.com/una9-plus-intelligent-parallel-charger-set-with-charging-nanny-protection-_g460.html

https://www.youtube.com/watch?v=2K0HqtGlhM4
 
Markz. I love you it's the middle one !!! Hey Markzee what you doing tonight ?... Yes yes I just brought one . Yes just know. 99.00 usd plus 47.00 shipping I did press 32.00 shipping but will take that up later Im in rattle snake canyon. Many fire on the other side of freeway east. The wind is just starting to blow from the ocean the clouds were hanging and keeping a cap on a smoke here now the wind is coming from the ocean and blowing it hope everything's alright on the other side.
 
Review 8-- 6s at up to 8amp per channel so 4 amp. Really just ordered as of now and when received will post up I already have a una 9 + plus charger and meanwell.
 
One of the major drawbacks of the UNRC 9 Plus + with the nanny is that you must break your battery pack that are in series in order to charge.
 
Oh yes . As I bulk charge two 12s with two 6s sense wire each . So four 6s. I only use the balance charger after end of charge to balance pack. But my A123 20ah pack rarely goes out of balance. So only used it 5 times in 1.5 years. It would work from for my pack if charge from lvc as its two 12s packs and I couldn't charge just 6s at a time. ??? But with lipo you can ez break the series connection.
 
Serious 1-ton of threads on lipo charging and different methods of balancing bleeding down charging up do some reading before you spend the money. And watch the neighborhood 4 a good use barbecue and charge them in your backyard.
 
Exe is right. So each or pack many ways safe can be done many ways with different levels of safety for the first timer one timer they always buy one extra pad because HobbyKing as DuDs. Always start from the beginning and write down every pair you get yes 18 sales 18 takes a voltage written down on a piece of paper start there and see what's happening I mean you ain't the brain that can remember all all the time.
 
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