LiPo battery care and basic information

[The Mighty Volt]

Broadly, yes, they are LiPo; the most "dangerous" kind. :lol: That's what I have here.

I have not built my pack yet but I am highly likely to use the method that doesn't require soldering to them. Build a containment box of wood, screw down brass bars across the tops of each parallel row, attach battery spring contacts to the bars at each battery pole point. Wire up balance wires to each brass bar, and the main input and output wires to the two end bars. Enclose it all in whatever is appropriate for your use. There's a thread specifically about this method, but I dont' remember what it's called.

If you have that cell welder built you can also use that to put them into packs.

Basically any method that gets you the pack shape you need that works for any cylindrical cell is ok.

Actual configuration depends on final nominal voltage you want. 3.6/3.7V per cell. Ah and C rating depends on the manufacturer, thus parallel amounts needed depend on how much current peak and continuous you need out of the pack, and how many Wh, vs what each cell is capable of.

BMS can be anything that supports the 3.7V max and ~3V min of these cells. I'll be using a F/G v2.6.

If yours are marked with a specific manufacturer, get their datasheet and go by whatever that says for max rates/etc. Most of mine are Sanyo URF18650 I think.

Anywonder they were so cheap.

Top post Amberwolf, thanks as ever for your assistance.

Whats the retail on that F/G BMS?

And what sort of power do you find your LiCoO2 pack is dishing out.??

Cheers.

 

[amberwolf]

Anywonder they were so cheap.

Easy to find LiCo for cheap; it's been used so long in so much portable consumer-electronics with bigger packs; laptops, DVD players, video cameras, etc.

Whats the retail on that F/G BMS?

Mmmm... RechargeableLithiumPower had them for I think $150-$160 assembled? Can't remember; mine's kit form--still assembling it (got a few parts yet to get, too). I may be blind today because I didn't see them on the site, Ask AndyH; he builds them up.

And what sort of power do you find your LiCoO2 pack is dishing out.??

It's not assembled yet, was still testing and sorting cells cuz I'm super slow most of the time. It's expected to be able to do at least 2A-4A per cell constant, paralleled in sets of 10 that's up to 40A constant, for theoretically half an hour. I have about 200 left to sort thru (of around 350?), so far about 60 rejects for one reason or another, some totally dead, some just discharged down to too low a voltage to safely recharge as part of a pack, or too low a capacity to bother with, but might still be usable for individual cell purposes for lighting and such.

So I can make 36V packs of 10s, with 30p, that are capable of 60-120A, at 60Ah total, if I end up with 300 working ones. Even if there are only 200 working, that's still up to 20p, way more than I need for one bike except for longer trips or maybe the SpookyTooth race, assuming I get anything done by then. :lol:

 

[Ykick]

I can't say enough good things about my little iCharger/Chargery 106B+ charger I bought along with my Turnigy Lipo's. My bike pack is doing great. Running really hot 15S 20C puts me around 30MPH with 35A controller. I've decided a top charge about 4.15V suits me fine. In fact, for future packs on my non-suspension ride I feel 12S lipo would be plenty.

One surprising thing is how many old battery packs I've been able to scavenge cells from because of the knowledge I've gathered using this charger. I opened old laptop packs and woke-up a nice batch of 18650 cells. Most are in good shape and very serviceable for various accesory duty. Mostly lighting but it's nice to have the ability to make cell level qualification.

I dare say - it would be smart eBike marketing to inform people that an eBike can be a relatively affordable entry into electric vehicles. Think about it? In the not so distant future more people will be making relatively large purchase decisions related to buying electric cars. The smart consumer will have an advantage if they already understand the fundamental basics of electric vehicles. eBikes are a great entry level way to explore this developing technology.

 

[amberwolf]

For those very few that care about how their appliances work, that's true. But I have found that most of the people I talk to about electric vehicles of any type simply want them to work the same way their gas car does, without any maintenance of any kind.

Of course, their car doesn't actually work that way, but it's how most of them treat them--only fixing things as they break, and never maintaining them to prevent that from happening.

But they don't want to learn about EVs, they just want whatever they drive to be cheap and hassle-free. I'd guess that half the time I get into a discussion about any of the details of EV stuff I can see their brains turn off, and eyes glaze over; they just don't want to know any of that (even though they asked). And I'm not even talking my long walls of text types of discussions like I do here on ES (where in general if you're here you probably care about learning this stuff :lol.

Ebikes could still be a good intro to EVs in general, but to be successful they need to be as close to a plug-n-play appliance as possible.

 

[liveforphysics]

I recently acquired a job lot of LiCoO2 18650 cells. 3.7v and 1500 mAh.

Do these fall under this broad category of LiPo?

How would I wire these into a 36v 20Ah pack {i.e. XsYp}, and what BMS do people recommend.

Thanks.

No. LiPo = Lithium Polymer. Round cells use liquid.

As far as how to wire them, you're better off not messing with them.

I don't think I've ever seen anyone ever spend as much trouble on a battery before.

 

[bandaro]

ok, i have a question about charging, not lipo specific, but still lithium cells... i couldnt find a more specific thread.

i am fully versed in all the safety, voltage, balancing, etc stuff regarding the cells, been using lipo for several years, but i am thinking of getting 12 lifepo4 cells with a bms, and was wondering about the bms capabilities.

does the bms just balance the cells, or does it act as a charger as well when it is connected to the charger/power supplies ive seen? the chargers just have the 2 wires as the output, what is the output on these wires, or more specifically, what must the input to the bms be to charge, say, a 12s (36v) 10ah battery pack?

thanks for the help guys, there is some truly great info here.

 

[amberwolf]

Depends on which BMS. Some are just cell monitors, some are just top-balancing shunting types, some control HVC and LVC and cutoff any charge or discharge current when one is reached.

Which brand/model BMS are you specifically asking about?

 

[bandaro]

not a clue on the brand, but will be getting it from here: http://www.e-mtb.com.au/lithium-batteries-c-75.html?zenid=4b8e45f671aadf609614226fd6c044a0

the cells are on the page, but he doesnt usually sell the bms, but i sent an email his way and he said he can do it.

this was the battery charger in question, but i think i already have a substitute that will work: http://www.e-mtb.com.au/36v-5a-lifepo4-charger-w-alloy-case-p-239.html

 

[bandaro]

ok, cells, bms and the charger are all made by headway.

so can anybody tell me the output voltage of the charger (linked in post above) and what the bms is capable of doing? need to know if i have to buy the charger or if i already have a capable supply so i can put the money towards a better esc.

thanks for the help guys.

 

[02jze]

http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=6792&Product_Name=iCharger_106B-plus_250W_6s_Balance/Charger
do i still need the medic ? or will the charger show me and let me change voltages ?
http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=10328&Product_Name=Hobby_King_Battery_Medic_System_6S
And can someone explain the difference between these 2 packs ?
http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=9176&Product_Name=Turnigy_5000mAh_6S_20C_Lipo_Pack
and
http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=10357&Product_Name=Turnigy_5000mAh_6S_20C_Lipo_Pack_(DE_Warehouse)
And finally i looked but couldnt find a y connector for the balancing leads ? is there such a thing or do they need to be made custom ?

 

[bandaro]

the charger wont show you the voltage for each individual cell, but it will show total voltage, and it will balance them itself, so unless you want to check each cells voltage separately, the medic is not needed. alternatively you could use a multimeter to check the voltages...

same battery, but one is stored in hong kong and one in germany.

think you may need to make the y harness yourself, ive never seen them for the balance plugs either...pretty simple to make though just a solder and heat shrink job.

 

[vanilla ice]

I'm pretty sure that charger will show you voltage by cell. You can get parallel adapters that will do the balance connectors and the main leads.. just not from HK. I think tppacks is one place that sells them.

 

[GCinDC]

http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=6792&Product_Name=iCharger_106B-plus_250W_6s_Balance/Charger
do i still need the medic ? or will the charger show me and let me change voltages ?
And finally i looked but couldnt find a y connector for the balancing leads ? is there such a thing or do they need to be made custom ?

Don't know that charger exactly, but looks like younger brother of mine, the 1010B+, and have to imagine it has similar programming.

I have no idea what your experience w/ lipo is, but it looks like you're building a shopping list...

I was pretty intimidated by this stuff at first, so if it helps you or someone else great. Here's my attempt to explain some of the features:


Don't forget you need a power supply unit to go with that charger. It only accepts ~12-14V input, so if you're going to plug it into a wall instead of a car lighter or whatever, you'll need something like the A20.

I've got 8 5Ah packs. I've paralleled pairs, so essentially have 4 10Ah packs. To parallel the packs, I spliced the power leads, and took two JST-XH extensions, cut the end off one, and made a Y connector, paralleling each balance lead...

Hope that helps.

 

[The Mighty Volt]

Hi All

Can a Hyperion 6S LiPo battery be successfully connected, in either series or parallel, to a 3s,4s,5s or 6s LiPo Zippy/Turnigy battery of different voltage but identical capacity {5Ah}

Thanks.

 

[The Mighty Volt]

Hi again, as Columbo might say.....just one more question.....

I understand that one of the golden rules about LiPo is that one must not pull more C out of the pack than it is designed for.

I plan to order enough LiPo to make up to different kinds of packs:

A 72v 14Ah pack for use with a Crystalyte 72v 50A controller and a 5304 hub

A 100v+ 10Ah pack for use with a Lyen 100v controller.

What "C" rating would my packs need to have for them to be capable of being used with either of those controllers??

What minimum Ah rating should I ensure the pack has at all times when being used in conjunction with those controllers?

Many thanks indeed.

 

[Vanquizor]

The C rating you need is just your peak amps divided by the Ah capacity of your pack (in you first one 50/14=3.58). If you're carrying 10Ah+ for range with the controlers you indicated the C rate is more an indicator of quality of cell rather than a constraint in performance.

 

[The Mighty Volt]

The C rating you need is just your peak amps divided by the Ah capacity of your pack (in you first one 50/14=3.58). If you're carrying 10Ah+ for range with the controlers you indicated the C rate is more an indicator of quality of cell rather than a constraint in performance.

Hello Vanquizor, many thanks indeed for your help.

 

[EVan]

But they don't want to learn about EVs, they just want whatever they drive to be cheap and hassle-free. I'd guess that half the time I get into a discussion about any of the details of EV stuff I can see their brains turn off, and eyes glaze over; they just don't want to know any of that (even though they asked). And I'm not even talking my long walls of text types of discussions like I do here on ES (where in general if you're here you probably care about learning this stuff :lol.

Ebikes could still be a good intro to EVs in general, but to be successful they need to be as close to a plug-n-play appliance as possible.

That's the way I treat my EVs! Especially the girlfriend's car. It gets plugged in. It gets driven.
For a sport bike I might be willing to babysit it a bit, but not much.

 

[deVries]

Don't forget you need a power supply unit to go with that charger. It only accepts ~12-14V input, so if you're going to plug it into a wall instead of a car lighter or whatever, you'll need something like the A20.

Is it possible to use ONE DC power supply to drive several LiPo chargers like this one? ...Turnigy Accucel-6 50W 6A Balancer/Charger? For example, I have 5 of these, specs here:

Here: http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=7028

Can I charge 5 LiPo packs at the same time using ONE DC power supply outputting "the driver" voltage to power all 5 chargers? I assume the 5 LiPo chargers isolates each one unto itself with each LiPo pack, meanwhile all 5 chargers can share the main "driver input" or source of 12-14v from the DC Power Supply without any problems??? Correct or No?

If no, will it work IF the main/source DC Power Supply driving the 5 chargers has ONE isolated 12-14v output it then shares and powers the 5 LiPo chargers??? No diodes or 5 isolated outputs required


Thanks!

 

[GGoodrum]

Can I charge 5 LiPo packs at the same time using ONE DC power supply to power all 5 chargers? I assume the 5 LiPo chargers isolates itself with each LiPo pack while all 5 chargers can share the main/source 12-14v DC Power Supply without any problems??? Correct or No?

Not correct. These chargers do not have isolated outputs. The negative output is common with the negative 12-14V input. If you have the packs separate, and not connected in series, then yes, you can do use multiple units driven from a common 12V input source, to charge the packs at the same time.

-- Gary

 

[deVries]

Can I charge 5 LiPo packs at the same time using ONE DC power supply to power all 5 chargers? I assume the 5 LiPo chargers isolates itself with each LiPo pack while all 5 chargers can share the main/source 12-14v DC Power Supply without any problems??? Correct or No?

Not correct. These chargers do not have isolated outputs. The negative output is common with the negative 12-14V input. If you have the packs separate, and not connected in series, then yes, you can do use multiple units driven from a common 12V input source, to charge the packs at the same time.

-- Gary

Thanks Gary. 8)

I assume packs can remain in parallel to be charged all at once after I disconnect any series connections? :wink:

 

[GGoodrum]

I assume packs can remain in parallel to be charged all at once after I disconnect any series connections?

Yes.

 

[deVries]

Shoot, I forgot to ask my other question.

According to the specs for those LiPo chargers shown here:

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=7028

Spec.
Input Voltage: 11~17v
Circuit power: Max Charge: 50W / Max Discharge: 5W
Charge Current Range: .1~6.0A

If I'm going to power 5 of these chargers, then I assume there might be some formula for me to decide how many amps my source charger should have if I want to output 6amps to each of the 5 LiPo packs.

Would this mean I need at least a 30amp source/input charger: 6amps x 5 chargers = 30amps? Maybe allow a bit more for good measure and efficiency loss, say 40amps?

Since I only need a 12v charger, what would be a good value charger to get -brand? Good quality (should last many years) but low total cost including shipping. Meanwell or SLA charger?

Thanks again...

 

[deVries]

Each cell charged individually, making charging quicker than other chargers that charge and bleed cells to balance them.

Anyone know if this is an isolated charger because of the above spec and it's dual charge capable below?

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=2055

hexTronik Balancer/Charger Dual Charge Capable (JST-XH Plug)
This charger differs from others in that it is built to be used in your car when at the field. It doesnt require a complicated wiring harness and fiddly button pressing/LCD reading setup for each battery. Just plug your pack in and it starts charging. Its robust case and built in charging fan ensure its operation long into the future.

Input Voltage : 9~15V DC
Output : (8.4v x 2) OR (12.6v x 1) OR (16.8v x 1)
Auto balancing
Auto Overcharge Protection
Size: 132x82x35mm
Weight: 309gr
Each cell charged individually, making charging quicker than other chargers that charge and bleed cells to balance them.


Thanks.

 

[daddz]

forgive my lack of knowledge, but that charger in the post above.
could i just buy several lipo packs to get my 24v 20 or 30amps. then just charge them a couple at a time? if that is so, could i also build up some sort of connection board so that i just plug each battery into its slot to build them up into 24v 20amp? then i could just wire my motor up to the board? would this be a safe reliable way to do it?
if that is possible how many batteries of what type would i need?
what i would really like is for some one with exp to jump up and say buy this do that and bingo. but i need to learn at the same time