TwoWayStreet
10 mW
- Joined
- Sep 13, 2013
- Messages
- 34
But it does not turn itself off and continues to bleed until the cell dies. Do you always tell lies, or just half truths?dnmun said:
48 v 35.2ah li-ion battery pack
- Thread starter Humberto
- Start date
TwoWayStreet
10 mW
- Joined
- Sep 13, 2013
- Messages
- 34
A little knowledge is a very dangerous thing to have.agniusm said:
Do not compare the battery management systems in laptops batteries with the junks you and that delusional HP retired scientist are promoting. Laptop BMSes are designed by real engineers, are tested and proven. The stuff you two are promoting are "designed" and built by idiots.
The following has been said by many people before, you two are just too thick to understand: A WORKING BMS is A REQUIREMENT for all lithium battery. The problem is NONE of the BMSes for ebikes works, therefore they should not be used.
agniusm
1 MW
Don't know how mine survived for two years. Calling people names over and over again does not help. Who are you anyway to make such statements? You have few posts, and make bold statements without any backing. Many top members with quiet few builds are using these same "idiot engineers" BMS'es, some work, some does not, you get what you pay for as mentioned before! Here is the list of some: http://liionbms.com/php/bms-selector.php, i am sure it could be used on a bike.TwoWayStreet said:
[youtube]nuCDUj2L7Wc[/youtube]
dogman dan
1 PW
:| I just wish I had a dollar for every thread that turns into a bms or balancing strategy fight.
dnmun
1 PW
i just wish one of them would learn how a BMS works instead of wasting their time going through my biography.
it is nice to think people care enuff to read what i did when i still was working, but you missed the stuff in my life before i joined the dawn project development group that created the nmos3 process in 1981. before that in 1976 there is the discovery of the regulation of hexose metabolism in spermatozoa by c-AMP during maturation as it moved along the epididymus.
the development of a photo depositon process for depositing silicon dioxide on planar surfaces at CSU in 1980. my master's thesis was on using Mossbauer spectroscopy to determine the force constants in rhodium and iridium using a third order Debye model from data collected using one of the earliest DEC11-20 computers when they were first invented in the early 70s.
but nice to know they care, even if he is still ignorant of how a BMS works
it is nice to think people care enuff to read what i did when i still was working, but you missed the stuff in my life before i joined the dawn project development group that created the nmos3 process in 1981. before that in 1976 there is the discovery of the regulation of hexose metabolism in spermatozoa by c-AMP during maturation as it moved along the epididymus.
the development of a photo depositon process for depositing silicon dioxide on planar surfaces at CSU in 1980. my master's thesis was on using Mossbauer spectroscopy to determine the force constants in rhodium and iridium using a third order Debye model from data collected using one of the earliest DEC11-20 computers when they were first invented in the early 70s.
but nice to know they care, even if he is still ignorant of how a BMS works
TwoWayStreet
10 mW
- Joined
- Sep 13, 2013
- Messages
- 34
Thank god I did miss that stuff. I think I would puke if I was forced to know about it. Especially if it has the same level of ignorance you've shown in your understanding of junky BMSes. Especially if it is as pretentious as your knowledge about laptop battery management systems.dnmun said:
I didn't have to go through your imaginary biography. I was forced to listen to your childish bragging about your make believe accomplishment. The technicians who work for me know a lot more than you and they don't brag. So tell me, were you really a scientist or an assembly line worker?
Humberto
10 mW
The top and bottom balance video that was posted was such a headache to digest that I don't want to ever think about battery maintainance to that extent. I just want my bike to get me to my fishing spot, and I don't want to sleep with a fire extinghisher every night that I recharge my pack. The above video has caused me to lean towards a factory made battery pack instead of worrying about a fire hazard. I'm now faced with the option of recharging my battery pack out doors on the terrace in order to address the fire hazard. Thanks for raining on my parade.
agniusm
1 MW
Thats why you use BMS. I dont think you will find a battery you need off the shelf. That video an few other were made for people to understand that battery management is a must. Safest option will be going cylindrical lifepo4. There are few steps you could do. First install series fuses, thermo switch. Get the cells you choose and get someone who works with batteries to spot weld and build up the pack. Look into Easons @ FoundingPower BMS.
Humberto
10 mW
Thank you Dogman, my bike photo is posted in part 3 under your photos.
dogman dan
1 PW
Re the range question for two hours of riding.
Is that an aotema brushless kit? Looks a bit like one. Or is this the brushed motor that looked identical?
Range and riding time depends on many factors. For speeds of 20-25 mph, 1 ah of 36v battery per mile works well as a rule of thumb. This rule includes a reserve for the windy day that takes more. But you can double that distance by slowing down to below 15 mph.
Two hours is a long time to ride. Typically an hour of riding 20-25 mph takes a pack of about 700 watt hours. Carrying more than 700 wh on that bike will be difficult. I rarely recommend using a knapsack, but that might be the best approach for you. Put some of the battery on the bike, then carry the rest in a pack.
Is that an aotema brushless kit? Looks a bit like one. Or is this the brushed motor that looked identical?
Range and riding time depends on many factors. For speeds of 20-25 mph, 1 ah of 36v battery per mile works well as a rule of thumb. This rule includes a reserve for the windy day that takes more. But you can double that distance by slowing down to below 15 mph.
Two hours is a long time to ride. Typically an hour of riding 20-25 mph takes a pack of about 700 watt hours. Carrying more than 700 wh on that bike will be difficult. I rarely recommend using a knapsack, but that might be the best approach for you. Put some of the battery on the bike, then carry the rest in a pack.
Humberto
10 mW
Dogman, I can't answer your question. I bought my front wheel kit on EBay and everything on the wheel is in Chinese. One of the online merchants led me to believe that 48 v. would push a 20" bike to 30 MPH. That was the only reason I bought a 48 v system.
dogman dan
1 PW
If it has three or more wires coming out of the hub, it's a brushless motor.
Only two large wires from the hub, would be a brushed motor. Brushed motors use about 20% more power per mile.
If it's what I think it is, it will have three large wires coming out of the hub, and the side will say AOTEMA on it. If so, that motor would go 30 mph on 48v with a 26" wheel. I'm not sure how fast on 20" wheel, but slightly slower for sure.
Only two large wires from the hub, would be a brushed motor. Brushed motors use about 20% more power per mile.
If it's what I think it is, it will have three large wires coming out of the hub, and the side will say AOTEMA on it. If so, that motor would go 30 mph on 48v with a 26" wheel. I'm not sure how fast on 20" wheel, but slightly slower for sure.
Humberto
10 mW
Dogman you are right. Under the Chinese writing is the name Aotema . However, I can't really count what looks like 2 wires without removing the cable housing and black tape. Take a good look at the included 3 prong connector that came with my charger. Which prong is for the red or black wire and what is the 3rd one for?. ....
Attachments
dnmun
1 PW
you got the wrong charger. that is for 240V in australia and europe, not the US. you can check polarity of the output with a voltmeter if you ever find a way to power it up with 240V and the euro plug.
Humberto
10 mW
Dnmun, you failed to read the charger specs on a previous post, read before you write. My question was directed to Dogman, whose advice I trust.
skeetab5780
1 MW
just lop the cord off and wire it to 240v it'll work, and if it has a 120/240v switch on the input side you can just switch the cord to a standard nema 5-15 male plug
Humberto
10 mW
Do you think that people in NYC are so dumb that they don't know how to buy a simple adapter for the wall socket. Go to hell and read the charger specs in part 3 and then open your mouth with some accurate information.
dogman dan
1 PW
I'm no genius, Dnmun is far more knowlegable about chargers and batteries than I am. But if you insult him, he won't help you.
I'm not so sure an adapter will make your 220v input charger run on 110. But if you have a 220 plug, like a stove or dryer plug then you can use that with an adapter.
On the discharge end, use a voltmeter to determine which of the two prongs is +. If you have the + voltmeter probe on the + wire from the charger it will read a positive number. A negative before the number means you have the probe on the - wire. Make sure you have the red wire in the right hole on the voltmeter.
The middle prong you can just ignore. It's just there because the manufacturer is misusing an AC computer plug to save money.
Back to the motor, it should be fairly obvious if you untape the plug, whether you have a brushed 2 wire plug, or the brushless 3 wire plug.
I'm not so sure an adapter will make your 220v input charger run on 110. But if you have a 220 plug, like a stove or dryer plug then you can use that with an adapter.
On the discharge end, use a voltmeter to determine which of the two prongs is +. If you have the + voltmeter probe on the + wire from the charger it will read a positive number. A negative before the number means you have the probe on the - wire. Make sure you have the red wire in the right hole on the voltmeter.
The middle prong you can just ignore. It's just there because the manufacturer is misusing an AC computer plug to save money.
Back to the motor, it should be fairly obvious if you untape the plug, whether you have a brushed 2 wire plug, or the brushless 3 wire plug.
major
10 kW
dogman said:
If I understand this, an IEC plug is intended to be used for the DC charger connection to the battery. That would be grossly irresponsible for a recommendation and invite the mistake of connecting the AC mains directly to the battery. Besides damage to the equipment, that could be hazardous to people and property. You should not re-purpose AC plugs to the DC circuit.
dnmun
1 PW
i think what he meant is that the charger guys decided to use the IEC plug because they are so cheap because they are so massively manufactured. and they maintain polarity also.
there are actually differences in the types of IEC plugs too. but the ones used for the AC plug are standardized.
there are actually differences in the types of IEC plugs too. but the ones used for the AC plug are standardized.
major
10 kW
dnmun said:
Right. So anybody can take a common computer power cord and hook AC directly to the battery. That sounds like fire, injury or fatality waiting to happen.
dnmun
1 PW
i don't this guy will do that. but give him a chance.
when you examine the failure mechanism if someone did apply the AC plug to the battery i doubt if those three results are the consequence.
the AC would immediately break the mosfets in the BMS and blow them open circuit so there would be no current flow into the battery or out of the battery.
the advantage of the IEC plug is that the leads inside the plug are separated by a thick layer of insulation, which is not the case in the XLR type plugs which regularly short out inside the plug when the lead is broken inside the plug and flops over against the other pin.
when you examine the failure mechanism if someone did apply the AC plug to the battery i doubt if those three results are the consequence.
the AC would immediately break the mosfets in the BMS and blow them open circuit so there would be no current flow into the battery or out of the battery.
the advantage of the IEC plug is that the leads inside the plug are separated by a thick layer of insulation, which is not the case in the XLR type plugs which regularly short out inside the plug when the lead is broken inside the plug and flops over against the other pin.
dogman dan
1 PW
True enough, plug problems are very common. If the charger plug has some kind of notch or whatever that makes it impossible to use a common AC computer plug instead, then I take back what I said.
I thought they were identical, allowing the possibility of easily plugging AC current into the battery. I have no problem with the plug on the AC input of the charger.
I thought they were identical, allowing the possibility of easily plugging AC current into the battery. I have no problem with the plug on the AC input of the charger.
dnmun
1 PW
they are the same. i just observed that if someone is silly enuff to plug the AC into the battery the results are not as bad as he implied. but there are different IEC plugs. on some of them the spades are narrower and fatter, but they seem restricted to 220V AC uses.
major
10 kW
dnmun said:
Not all batteries have a BMS, and fets do fail shorted. Also, a failed unit with high voltage AC applied could leak to the enclosure imparting shock to the person touching it. The BMS and battery were not designed and built to withstand 110 or 220VAC. You can't predict the failure mode will always be benign. Like I said, I think it is irresponsible to use an AC plug or socket on a battery. Even dogman called it a misuse.
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