Charging to 80% without a Satiator
- Thread starter Justin Fischer
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tomjasz
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Yeah, drama making a simple rule complicated. 3.6-4.1. All good. 3.2 on occasion, no problem as with 4.2.
Let’s relax and ride. 48f in Minnesota this week. Woohoo I voted for global warming! I kid, this scare the beejeebers out of me.
tomjasz
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See Felix. He’s sorted it. Sorry sarcasm and personal pokes from nom de plumes frustrate me.I have a headache and I just found this thread.
I was wrong to call an 18650 a lipo. I use the term lipo so much in my business I tend to call anything with lithium in it a lipo. So my apologies for that. But this thread is about voltage percentages and everything else I posted was correct. i don't like being accused of posting false info. My post are to help inform those that want to understand the care and feeding of our batteries. See I almost said lipos. I hope I was able to help some of you guys about the importance of cell percentages and how to use them. Seeing that chart from juice got me going and I have an ebike just like the rest of you. I want my battery to last just as much as you do. If anybody has any question on your battery feel free to ask.
tomjasz
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Here dude, you’re good! The numbers for LiIon (NMC) are really close. I get that you were honestly trying to help with no malice or reason to provide inaccurate info. It all gets confusing. I’m in the keep is dimple stupid crowd. For a majority of 18650 batts, 3.4-3.6 and 4.1 are a great parameter for longevity. I’m looking forward to your batts for my spot welder. This is clearly NOT a LiPo forum.
linklemming
Well-Known Member
Im also curious as to your definition of lipo as (li pouch), I have been a RC hobbyist for the last 10 years(3d helicopters and FPV drones) and have never heard that as the definition of LiPo.
Im also going to call out Ravi saying that lipo fires are darwinism. I have had several friends who have had lipos catch on fire during charging (which dont use a BMS but true balance charging at the charger level). I have also seen lipos burst during flight conditions
The RC hobby (rc helis and FPV drones) have VERY high current requirements (typical 3-4 minutes flight times). Lipos are the ONLY solution to this. You typically wont even consider 18650s until your flight times approach 30 minutes.
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It's not my definition. It comes from the scientist in the industry. When I read about it they said the scientist wanted a way to differentiate from the metal cylinder cells. Since both are li-ion. It of course also stands for lithium polymer too. If you do a search you can find both definitions.
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tomjasz
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LiPo is fussy, drop the voltage bellhops spec, puffing and fire. Overcharge, fire. Ok for an Ric, but once you develop a pack large enough to have range you’ve got a maintenance nightmare. Lots of theold school
Guys run them and are happy. Imliv,me in Minnesota. It’s not safe to manage them in my basement . LiPo are best manged in a bbq. Not in the house. If you’ve ever seen a fire or tried to extigush one you come to realize NMC and 128650 batts are infinitely more forgiving. Sgogle lithium battery fires. It’s all there.
Guys run them and are happy. Imliv,me in Minnesota. It’s not safe to manage them in my basement . LiPo are best manged in a bbq. Not in the house. If you’ve ever seen a fire or tried to extigush one you come to realize NMC and 128650 batts are infinitely more forgiving. Sgogle lithium battery fires. It’s all there.
linklemming
Well-Known Member
Great, show me a 18650 that can support 3 minute flight times, If you can do such a thing you will TRANSFORM the RC industry and likely l make lots of $$ in the process.
I would love to see this as 18650s are much lighter for the same MAH. I have several planes that demonstrate this (i.e. readymade rc nanogoblin which get over 30 minutes of flight time due to using 18650 vs typical lipo pack which is much heavier)
I have the ability to measure cell IR on my 'lipos' vs 18650 packs, let me know what I need to provide
tomjasz
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Different animals for different purposes. Hobby packs save money. LiIon save garages and houses.
18650's won't be in RC (at least stuff that flies) because of the weight of the metal jacket. The reason there are few issues with 18650's in e-bikes is because the battery packs have BMS built into them and the chargers are not complicated devices for the user, they are "on" or "off".. With hobby lipo, the BMS is the charger and there's probably 100 different chargers you can buy, all with unique programming functions.. Hobbyists make mistakes, it's human. Charge your lipo on the NiMH setting and bingo, there's your fire. 18650's by themselves are no more stable than lipo's
tomjasz
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Almost true, 18650 batts are easier and far less volatile than RC packs. I will only use LiPo for my welder, and it's charged and stored in an ammo can. I remove the gaskets and keep mine latched for storage AND charging. Overcharged= fire. Allow to be discharged below 3.2V = fire. Pretty easy to maintain when they are small RC packs, but once a pack is built for an eBike with good mileage you've got a fairly large and volatile package. To cover the negative side...
I removed the gasket and drilled access holes. Yup it's a torch while burning, but it IS contained. I'll never own more than I need for my welder. I'll probably buy an SLA for welding once I've worn out my LiPo. Will buy from MarkF. While there was some stumbling, he does know his product.
The only thing that makes Li-ion less volatile than Lipo is the metal jacket. For all intents and purposes they are the same chemistry. Much easier to puncture or physically damage a Lipo resulting in fire.. Overcharge Li-ion, fire.. Over discharge? ,possible explosion. same-same
linklemming
Well-Known Member
Not totally true as I have RC planes using 18650s. If you have flight times over 30 minutes then using 18650s has a significant weight savings. An example of this would be the ReadymadeRC NanoGoblin.
For more current hungry aircraft like FPV Racing Drones and Helis 18650 has too high of a IR to support high current demands.
As an example
I have an RC lipo(Turnigy Panther 600mah 4s) here at storage charge and its showing 11mohms per cell. Note that IR goes down when fully charged so this is a little high.
I also have an 18650 4s pack (Titan 3500mah 4s using NCR18650GA) at full charge and its showing 50mohm per cell.
The story gets even worse IR wise when you normalize IR so each battery has same capacity.
Is this the right room for an argument?.... GENERALLY speaking, 18650's aren't used for RC aircraft, your aircraft is an anomoly.... 50mohm IR? LOL... Not in a 10s F5B glider......ever... Internal resistance is far more temperature related than capacity related
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linklemming
Well-Known Member
Are we having an argument? I think we are just discussing facts....GENERALLY speaking
I agree 18650s are not used due to their high IR(the whole point I am trying to make) but I gave an example of where they are (and situations where they could be used).
I would NEVER use them in my FPV racing drones which can have peak amps of 150A coming out of a 1500mah 4s battery with typical flights lasting 2-4 minutes nor in my 3d helis or cars.
Im well versed in what affects IR (yes temp is a big contributor and why I made the mesurements at the same temp) as its the primary thing that defines a lipos performance. I measure and keep records of all my LIPO packs.
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You'll get a kick out of this; My F5B glider uses a 10s, 1,800mah lipo pack and the amp draw is around 200 amps. The only way this can work w/o destroying the lipo pack (or the motor) is the motor is only run for 1-3 second bursts with a minute or more of recovery time between bursts. Obviously we look for Lipos with very low internal resistance .. With an 18"x23" prop, we're looking at around 8 HP and an estes rocket climb rate from a 69 oz. 2 meter "glider" Imagine this power system in an ebike.. LOL.. Sorry for the off topic post, back to our regularly scheduled argument now
.. With an 18"x23" prop, we're looking at around 8 HP and an estes rocket climb rate from a 69 oz. 2 meter "glider" Imagine this power system in an ebike.. LOL.. Sorry for the off topic post, back to our regularly scheduled argument now
devhead
Member
So...based on Mark's chart. I've been starting my ride with a 67% charge and finishing with a 3% charge. I thought I had been starting with an 75% charge and finishing with a 35% charge. My ride is 20 miles round trip with hills both ways. I have 48v 19ah battery pack and ride the CCS. I would typically start my rides with 50.7 volts and finish my ride with 44 volts.
Mark, is the below chart correct from your perspective?
Mark, is the below chart correct from your perspective?
