Living With Lipos--Safely!

cannonball2

cannonball2

Well-Known Member
As of recent with the appearance of the larger amp hour Lipo packs their use in Ebiking is becoming more attractive and widespread. There is a lot of controversy surrounding their safety. Some valid, some not. We have all heard horror stories about fires and for sure fires can happen with this chemistry when improperly handled. The point of this thread is to discuss these batteries in all aspects. Selection, use, charging, storing and disposal. Also the various hardware for charging.

I have asked Lungcookie to offer his input. He is a wealth of info on the subject as well as the hardware. He seems to have a link to anything! He pointed out to me the excellent threads over at Endless Sphere. Indeed there are and I suggest visiting there and reading. I felt it would be nice to have a similar thread with in this forum and present it in simple hands on terms. So here we go.

Ask questions, submit ideas, discuss needs for a specific build, what ever.

These batteries offer the greatest power density for the weight/money I see no reason not to use them in our hobby. BUT safety in using them is a MUST!

The basics are pretty simple:

Don't charge over 4.2v-EVER!

Don't discharge under 3.0v or the pack will likely be killed. For best pack life stay over 3.5v for the LVC.

DONT charge a HOT pack you are asking for trouble if you do. Let em cool first.

Don't try to "trick" charge an undervolted pack. Trust me its done for, and the results can be news worthy.

Use only equipment meant for the Lipo chemistry

These packs for max life should not be left fully charged but in a storage voltage. Don't charge them if you are not going to use them say in 24hrs. Lipo chargers have a cycle to bring them to storage voltage.

Keep your eye on puffed packs, I dispose of them. This is caused mainly by exceeding the C rating(common with R/C heli flyers, I have first hand experience). This is not going to be an issue with the mild amperages in ebiking, but any puffed cell is suspect. Can be caused by damage, and age also. If a pack has seen impact as in a bad drop or crash. Isolate it in a fire proof manner and observe it for an extended period.

Store packs in a fire proof container and charge on something besides the kitchen table. Something that is likewise fire proof, I prefer a large earthen wear dish, like under a large flower pot. Charging in metal spooks me.

ALWAYS monitor charging, don't leave or go to bed trusting the charger to handle it. That's another news worthy situation.

Use a pack checker to monitor the overall packs condition the individual cells and their overall balance. Charging a pack with grossly unbalanced voltage is another bad deal. The cells should remain with in a few % points of each other.

These are the basics. Its not as complicated as it sounds. A good charger will handle most of the condition checks and safely charge, but the situation is only as safe as you make it!

Add to or correct anything I have mistakenly stated.
 
I will most likely just be repeating myself, but I think this is a good idea to condense the LiPo info in one spot.

I am a hobbyist and have been since 1988.
I read and read and read.
I take notes.
I still mess up stuff all the time.
Live and learn.

I suggest these batteries, then turn around and tell members not to use them.

These are not the battery chemistry to use if you if you want a 'safe' and 'easy' battery that you charge once a week and ride a bit every day.

Let me explain.

I posted the 5.0 thread and not 2weeks later someone burnt down their garage here in the city I live in. Charging up an ebike. I Have no idea of the reason or details of the fire.

1 week after I started that 10.0 thread another fire, guy charging LiPo for hellis.


That has made me a bit gunshy to suggest these to new users.
I really don't want to read about one of you members burning up because they read something I posted, not knowing all the dangers.

CB2 and I have been using these hobby LiPo for the last year without to much trouble.
CB2 has a background in hobby R/C.
On Endless-Sphere they have been using them for many years and bulk charging with no problems. That said, even some E-S members have torched their bikes and more, bulk charging.
Something we fail to note is the fact we both CB2 and I had chargers to begin with so that helped the LiPo switch.

LiPo is all around you, in phones, remotes you name it.
It is generally the user that seems to be the weak link.


Looks like CB2 has covered most of it.

4.15v/cell to 3.5v/cell for long life.
Don't run them lower than 3.0v/cell.
Store them around 3.8v/cell.
If you run them under 3.0v/cell then try charging them is when bad things can happen.

Pay attention to your charging location.
Remove any flammable material.

Don't poke a hole in the pack, that creates a fire-ball.
Don't drop the pack, if you do keep an eye on the cell voltage for possible damage.
Don't use anything sharp around the pack.
Protect the packs from drops or bumps if you drop the bike, yes it happens.

Monitor each cell voltage if you want to play it safe.
Don't run them without some way to monitor your voltage.
If you don't use a BMS(Battery Management System), you are now the BMS.

These new Turnigy Multistar packs, in my eyes are a better way to go than the 5.0.
It removes most of the connection/plug mess.
10.0/12.0/16.0/20.0ah packs.
They are smaller and lighter.

Two, 6 cell packs, negative to positive, will get you 50.2v off the charger.
Usable for most 36v-48v systems.
Most modern balance chargers have multiple safety features that make them a no-brainer to me.
Especially with the ease of the Multistar packs.

Some extra reading.
https://endless-sphere.com/forums/viewtopic.php?f=14&t=52240

https://endless-sphere.com/forums/viewtopic.php?f=14&t=26621

https://en.wikipedia.org/wiki/Lithium_polymer_battery

CB2 nor I are responsible for your actions.

Good luck, and be safe.
Please ask about anything you don't understand... and feel free to correct any bad info, please.
Wont hurt my feelings.
The point of this thread is to try and keep everyone SAFE.
 
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My understanding is the main thing you don't want to do is overcharge them and that includes trying to charge them too fast with too many amps. Take your time and use less amps its better for the battery life.
 
Thanks for creating and contributing to this thread. One suggestion here from an ebike wannabee is to share a glossary of terms. What is commonly understood shorthand for you guys may be gibberish to a newby. For the foreseeable future I'll be operating with heavy weight lead acid batteries, but when the day comes that they need replacement I'll be sorely tempted to go lipo. With the help of you guys and this thread I'll know better how to go about it without harm or wasted money/effort. Many thanks.
SB
 
OK SB a few terms.

C is the face value of the pack. 1C in other words. Taking a 5ah pack rated at 10C means in theory the pack would yield 50amps for some duration 20C 100amps 30C 150amps etc. C is also used for charge values. Most packs are charged at 1C though some are capable of being charged at multiple C. That's not something I do, I charge no higher than 1C and sometimes less.

Nomenclature of packs is as follows:
A 4s pack for instance is 4) 3.7v cells in series making a 14.8v pack.
If there is a P in the letters it means the cells are also paralleled in some manner. You don't see this much anymore. It was early on when individual cells were small and were paralleled together to make a larger capacity. The packs voltage is referred to at its rest voltage @ 3.7v/cell. I prefer off charge voltage which is 4.2v/cell. This prevents blowing something with a fully charged battery that might come in in the acceptable voltage range at rest voltage.

Balance is the voltage relationship of the individual cells with in a pack. Ideally they should be the same or very close. The chargers these days balance while charging. Wasn't like that in the early days.

Of course there are many different connectors on the packs and they increase in size as the amperage increases. I wont discuss them, just ask questions when necessary.

There are ebike specific terms thrown in to battery discussions such as LVC- the low voltage cut of the specific controller. This value is very important with Lipos.

Probably left out a term or two so ask specific questions.

Hope this helps.

Maybe we can get LC to throw in on chargers. He is well versed on them. I'm still using my 2013 vintage 5amp units which have worked flawlessly. I wouldn't mind upgrading to higher amperage units.

Suggest away LC!
 
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The first charger I used for R/C back 1988 just had a 15min. timer and a amp meter.
You could get the NiCad real hot sometimes if you didn't pay attention.

Most of these modern BALANCE chargers are like little computers.
This Reaktor I run now I really like, I would say anything with at least 10a/125w would be sufficient for 25v packs.

I think I got link happy on the 10.0 thread with charger ideas.
whoops Starting here...actually in the 10.0 thread
http://motorbicycling.com/showthread.php?t=59502&page=4
pg.4 post #40 & pg.5 post #42
 
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Wonderful thread. At the end of the explanation, I'll ask a specific question....Oh, I hope I will get some (more) guidance.

I've read every word Lungcookie, CB2 and all of you have written on the Lipos.

I purchased eight 5.0's from HK, established my account with them, got all excited about my first e-bike build
(had an ebike before, but didn't know a controller from a fet) and then pulled back after a safety warning from Lung.
I just got my full $204 refund to my Paypal account from them this morning.

CB2 gave me some great advice in several PMs. As did a few folks posting links on bottle and dolphin batteries.

After deciding to stick with the SLA's out of a bow to economic reason, and forestalling the Lipo move until I was "smarter",
yesterday, I completely pulled apart the donor bike that is/was carrying the 1000w, 48V, with four monster 12ah 12v batteries.

I started to make a wooden box for 16" of lead batteries, started calculating what bike/frame to go with, and then realized why I was
doing this....I want to build something that isn't a 900 pound behemoth that won't carry my (too) ample weight with the flickability
of the USS Arizona.

I like the idea of running for a long period of time. But the reality is that I probably ride more like ten minutes at a time
(albeit at higher power/speed than I should) than ride on a weekend tour.

So, I got irritated.

I figure a guy should be able to, if not master this, at least understand, be safe, and get the job done by adding reason, diligent monitoring,
and the choice of the proper equipment.

With a ton of wrenching under my belt (not related to electrons, except for the fundamentals of 12 "classic" auto wiring where you
really only need to know what are positive and negative and what is series or parallel), safety conscious (raised three kids...girls to women...
and am patting seven grandkids on their butts now), willing to observe the rules of safety.....Enough. You get it.

I'd like to know what I need to buy to run this front hub rig...maybe with the 10.0's to get to 20Ah....(I can't get to the stats page now because
I'm writing this book..., but I think I remember that the volts on the 10.0's would require three batteries)...a battery charger/off bike bms that would
do the job properly...a bms/meter for the handlebar of the e-bike,....... and what else?

I'll build the safe box, establish a safe place to charge (with a heat sump and fan), the diligence and monitoring, the research and rule
following that you have all been so kind as to have provided re: balance, overcharge, storage voltage, discharge rates, discharge levels,
eyeballing the packs for bulge, and everything else I have or will read about...

The inquisitive fiber I have running thru me won't allow me to get an either overpriced bottle battery, or give up on building with this technology.

I know it's asking a lot, but would someone punch-list a system for me using that hub? (really overstepping, here...with links to the hardware?)

I'd really like to send silverbear these new SLA's for his ride.

Again, many thanks to both CB2 and Lungcookie for past information and keeping the focus on the sport with an emphasis on safety.

I have a smugmug link with a million pictures that I already posted elsewhere. But here is a pic of the donor bike and the inside of the controller.
The system is now cleaned up, off the bike, and works perfectly with those big batteries.

Thanks to all for the help.
 

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If you just want to charge it up once , then ride a little bit each day, these are not the battery chemistry you want. Stick with the LiFePO4 or LiLo.

If you still want to run a smaller lighter LiPo and can follow simple safety precautions...
Take 2 of these and call me in the morning. :)
http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=80908
Would be the easiest way to get 20ah. Positive to negative to hook them up.
simple
$158.40 dropped to $138.60, after you sit there on the web page for a minute or 2.

Three would be 75.6v, not knowing what your control is rated for...most of the 48v systems seem to be 63-65v fets or so max.

I am running two, 6cells and one 4cell for 67.2v hot.

So with two 6cellx2=12cell=50.4v hot off the charger.

Fully charged one 6cell will come off the charger at 25.2v.

Get at least a 10amp/125w output charger.
10.0 thread for links.
Shop around, HK is not the only game in town.

I am the Cycle Analyst fan boy here so I will all ways recommend the CA3.
http://www.ebikes.ca/shop/ebike-parts/cycle-analysts.html
Another $150-$155.
CA3-DP for direct drive hub.
CA3-DPS for geared hub or Mid drive.

Can reduce the amps with the CA3, that controller you have looks to be good for 75amps.

Don't need to have CA, they sure are nice.
Just really need a voltmeter of some sort.

If I scared anyone with the LiPo fires in town....good.
Just play smart, its not that hard.
We use gasoline every day, in the wrong hands gas can be VERY dangerous.
 
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Thanks for the links K007! You have to watch the Imax. There are a bunch of out right copies out there that were problematic. I had one. If you buy from Hk they sell the clones and tell you so. They also indicate which ones are genuine. Heres the genuine, read the explanation at the bottom of the chargers description. Too funny! the price of the genuine is almost double the copy. Equipment like the fake probably has a lot to do with battery issues/possible failures/fires. Buy well my friends! http://hobbyking.com/hobbyking/stor...er_Discharger_1_6_Cells_GENUINE_AU_plug_.html

Magwa, LC has given you a pretty good road map on the Lipo selection. I am running the 6s 10ah(2) on my 48v system and its ideal. If I want to hot it up a bit I just parallel two 5ah 3s packs I have, then series them in for 63v. But two 6s make a great 48v system. Its a few volts shy off the charger but the LVC at least on my controller is right on the money. Unless you are in the middle of hill country 10ah is plenty and they also make for a fairly small power module that will fit nicely on the down tube of most bikes.
 
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kevyleven007 said:
Hey check this out! http://hobbyking.com/hobbyking/store...e_Charger.html or cheaper http://www.ebay.com/sch/i.html?_fro...2.TRC2.A0.H1.Ximax.TRS0&_nkw=imax+b6&_sacat=0 watt meter- http://www.ebay.com/itm/261643073592?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT Those 20ah packs are a good deal if the quality is good. I might be getting a couple of them pretty soon.
Click to expand...

These B6 style charges state 5amps. but it will only put out about 3.5 amp, charging will take longer.
V x A = W
25v x 5a = 125w
I have one. However mine is a SkyRC B6AC+, plugs in the wall. Good charger, from 10 years ago. Cant comment on the new ones.

Get something with at least 10a/125w output.
http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=70748 $33.15
Wait for the price drop. min or 2.

Get 1 charger for each pack and a power supply.
Then you will still be able to charge if one conks out or something and you will be charging in half the time if you get 1 per pack.

Power supply, 250w-300w per charger would be good.
I can run this 2xReaktor off a 540w. As I charge at 5amps x 2, I only am using half power. Rated for 20a.

That wattmeter is only good to 60v, so watch it if your going over 14cells, will cook it.
 
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Okay, Guys.

You've created a monster now. Hahahahaha!

Batteries are on the way.

http://www.hobbyking.com/hobbyking/...0mAh_Multi_Rotor_Lipo_Pack_AU_Warehouse_.html

So, cutting through the learning curve on this (CB2; "LVC"? I don't know what that is).

You have seen my controller and the leads. I can not find a "mapping" of the leads to the controller.
Obviously, I see the phase wires and the primary power wires. I can also tell which wire *groups* go to the throttle.
In that group is the on/off button, throttle, and wires for the "full/half full and empty" warning lights.

So, the next group of questions on the Voltmeter/Analyst is: Can I simply monitor voltage from the pos and neg terminating-terminals of the batteries
(after wiring them to achieve the 50v)?
Do the balancers come into play on monitoring while riding? (I think not, but am here to learn). If I HAVE to find a connection to the controller
that will accommodate voltage monitoring, do you think it is related to the wires now measuring voltage for those idiot lights in the throttle housing?

Final question in this group: Given my set up with the two cells, is the Cycle Analyst CA3-DP the answer in terms of information and simplicity of
connection to the system? Or, is something else better when moving toward the simplicity portion of the matrix, but still allowing monitoring the
batteries "on the fly"... so I don't screw the pooch and wreck $287 worth of batteries (or worse).
 

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Magwa you scare me a bit.

LVC= Low Voltage Cutoff

Do not go under 3.0v/cell or you will kill these batteries, they are not like Lead where it will come back for more.

LVC 3.5v/cell for long life
That would be 12cell x 3.5v/cell =42v LVC

Monitor the overall pack voltage not cell level when riding.
The hook-up should all be the same as they are now. In its Lead battery working state. Lights on the throttle are worthless. Just creates heat.

Not sure if that 15fet control (seems huge, i run a 9fet) you have has the CA plug, so would have to figure out how to wire it...CB2 may need to do that too.
15fet at 5amp per fet is 75amps!
I run mine at 16amps, it will pull the front tire off the ground at 20amps.

You would want the CA3 that was for your type of motor, hub Direct Drive (DD) or Geared Hub specific.

You can use the balance charger to check cell level voltage, till you get a cell-log 8 or something.
Charger can discharge and get them to storage voltage of the packs.
 
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Lungcookie said:
Magwa you scare me a bit.

LVC= Low Voltage Cutoff

Do not go under 3.0v/cell or you will kill these batteries, they are not like Lead where it will come back for more.

LVC 3.5v/cell for long life
That would be 12cell x 3.5v/cell =42v LVC

Monitor the overall pack voltage not cell level when riding.
The hook-up should all be the same as they are now. In its Lead battery working state. Lights on the throttle are worthless. Just creates heat.

Not sure if that 15fet control (seems huge, i run a 9fet) you have has the CA plug, so would have to figure out how to wire it...CB2 may need to do that too.
15fet at 5amp per fet is 75amps!
I run mine at 16amps, it will pull the front tire off the ground at 20amps.

You would want the CA3 that was for your type of motor, hub Direct Drive (DD) or Geared Hub specific.

You can use the balance charger to check cell level voltage, till you get a cell-log 8 or something.
Charger can discharge and get them to storage voltage of the packs.
Click to expand...

Nothing to be scared of. I ask questions and learn fast.

More importantly, I don't do ANYTHING until I understand what I'm doing. I'm an old dog that can safely learn new tricks. But not without knowin' the lingo.
And, my ego evaporated long ago. I keep that powder dry for the flight or fight stuff...So, I'm not embarrassed to ask questions and follow instructions....

That's why all the questions.

So, tell me if I have this part right:

If LVC is 3.5/cell (42v in this case), and I'm only monitoring the "gross volts" while on the fly, if my reading reaches 43v, I better either be home or ready to shut
down and pedal home. Right?

There's no connection....wait, there probably *is*...that is, for which I'm aware out of the controller that would monitor the level of voltage.... except what might
be running those damned idiot lights.

So, the question remains, from connections to the power terminal pos and neg of the battery pack(s), can I run a simple volt meter to accomplish health and
safety of the batteries while riding on the road?

***********************************************************

Next, I have no idea what a CA plug is...Now don't laugh. There was a time you didn't either :) .....All my wiring and connectors out of the controller are there for
the world to see. I wouldn't know how to adjust the amps if they came to my house for Thanksgiving. 16 or 20? If that's a mechanical change in the controller, I'm,
once again, screwed without information implants from you guys. You "run yours at 16amps". Okay. Good. How do I run MINE at 16 amps?

With the working direct drive hub I have, is it too simple to say that, after properly and safely balance-charging the pack off of the bike (two chargers and two power
supplies to the prescribed top voltage specs from the 3.8 stored voltage), with my new batteries wired in series to achieve the 20ah 48+ volts, connecting the batteries
to the system (now working perfectly with those heavy SLA's), there is more to do while either riding or setting up the system than being vigilant about letting the
charge get lower than 3.0 or 3.1v/cell (but measured on the road by a combined voltage of no lower than 42v)?

I know there are a lot of questions here.

But, I also know there are a bunch of folks that benefit from your answers, CB2's answers, and other folks that might weigh in to help teach this stuff to us,
the unwashed that won't give up.

:-||
 

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Here is a simple and cheap volt meter. The biggest down side is 1)its hard to see in bright sunlight(read it in the shady parts on the road). 2) it will require a secondary source to run the display when the monitored voltage is over 30v. Run it on a 9v battery, will run a long time You will need to be able to disconnect the 9v when not in use. The meter itself just hooks to positive/negative connections on the battery side of the controller. This is a bare minimum but will do the job. When reading voltage be sure to do it while static, the values are a lot lower under load. http://www.ebay.com/itm/Mini-DC-5-1...eter-2-wire-/391243224792?hash=item5b17e9d6d8

I have to say you are the big kid on the block with the 20ah bricks! A single charge would last me a month I bet with the type riding I do! These should weigh in around 10lbs. That's the lightest 20ah pack I have seen yet. Congrats!

If your controller plugs onto the existing kit(connectors should be plug n play) then the only thing to mod is the battery/controller plug ins. Most controllers will have a few unused wires. I have a similar kit. Runs the throttle switch/display, throttle, brake interrupt switches, and of course the battery inputs and phase wires. If it was working on the SLAs just reinstall it the way it was.
 
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Yes, I made the comment that this all sounded like the adults talking in the Peanuts cartoons last year...now I am explaining things...yikes! take it with a grain of salt.
Old dogs can learn new tricks if they want to.

I am a bit blunt sometimes, just my nature. Apologies.
Ego's are a bit over rated in my book too.

Magwa I am glad you are asking questions.
You are bypassing the learning curve and stepping it up a notch.

You can use 1 power supply, just get a bigger 1.
For 2 chargers 500-600w, for 3 chargers 900w. just bump it up.

You need to connect positive to negative, SERIES, so with these XT90 connector that come with the Multistar you need the series connector that CB2 was talking about, I don't see any listed in HK. Maybe he can point those out.

What charger did/are you getting? Will it have the XT90 plugs?

I cut off the XT90 and use the Anderson PP45, just my preference, from R/C.
I use Anderson power poles pp45 terminals. Check eBay. Get spares.
It is just positive to negative then. Easy.
I don't know how they will handle 75amps however, that may burn them up.

CA plug would be a 6 pin black rectangular plug/connector on the control.
You will need to know the shunt value in ohms to properly calibrate the CA3.
If it came with a CA connection it would probably have a value marked on the control, example 2.42ohm or some such.

I modify the amps with the CA3.
Also throttle ramping, so it wont just hit full blast when you touch the throttle.
You can set a LVC with the CA3. Use it as a fuel gauge, speedo, temp sensor for motor.

I use a geared motor and it seems to take less amps than the DD to do the same thing.
My rear geared hub feels similar at 16a, as compared to my DD magic pie 3 at 20-25amps.
Me and my bike weigh in at 200lbs. together and ride in the flats most in the dirt.

If you weigh more and use a DD hub you will use more amps.

If you are at 43v and punch the throttle it will go lower than 42v. Voltage sag.
20AH will help, way worse with just 5AH for example.
If you want them to last don't run them lower than 3.5v/cell.
4.15v/cell to 3.5v/cell for long life.

Water proof voltmeter.
http://www.ebay.com/itm/DC-15-120V-...-Motorcycle-/251389600627?hash=item3a87fce373

Here is the control I am using.
http://em3ev.com/store/index.php?route=product/product&path=38&product_id=80
Controls with a power switch feature is nice because you don't get a big arc when plugging in your battery.

I like these throttles.
http://holmeshobbies.com/Magura-Twistgrip-5k-throttle.html
 

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