Powerstroll Wheelchair Adapters

[snoko]

I correcxted the above. Re read!

Those batteries are crappy so no big loss but you could try it.

the $$$ is a loss ... it would still be be good for my scooter though compared to that sealed leaded junk I had.

m

[Burgerman]

If the scooter is 12v. It will give a small 20Ah battery. If its 24v it will give an even smaller 10Ah 24v battery.

[snoko]

If the scooter is 12v. It will give a small 20Ah battery. If its 24v it will give an even smaller 10Ah 24v battery.

its 24volt scooter with 2 x 14 amp or optional 2 x 24 - which they never offered until I noticed it also worked on liteway 3 ( didnt want me getting more bang for my buck of course )

heres the beast itself ( except mine is the old version ) i got it 3 months old off ebay.. for under £400

snok

[snoko]

As mid sized scooters go - its almost radical compared to those ghastly red bricked basket cases ..

Who the hell goes around with a basket in this day and age ?

m

[Burgerman]

So you SHOULD be fitting 40 or 45Ah of lithium in the same space. This is the entyre point of lithium. Its about twice as energy dense.

Fitting the same Ah or less than you had before, is just an expensive way to achieve very little. And the more Ah you fit, the lower the C rate of cell is needed and the easier time they get too. So it makes them last longer, have a lower average discharge rate, which also makes them last longer. Or charge just a couple of times a week, so 2k cycles means 20 year battery life...

[snoko]

So you SHOULD be fitting 40 or 45Ah of lithium in the same space. This is the entyre point of lithium. Its about twice as energy dense.

Fitting the same Ah or less than you had before, is just an expensive way to achieve very little. And the more Ah you fit, the lower the C rate of cell is needed and the easier time they get too. So it makes them last longer, have a lower average discharge rate, which also makes them last longer. Or charge just a couple of times a week, so 2k cycles means 20 year battery life...

if I was using my scooter regularly that would makes sense , but if I can improve i am hoping to make this kw setup my regular ride ( esp if I plan to travel ) extra batterys would be good , but I wanted to use the cash on the charger for now until i get more confidence.

I wanted to test pings using the powerstroller , but how easy are they to open or safe ?

Why the hell are there so many people saying Ping are great ??????

To the best of my knowledge, Li Ping has never revealed the source of the LiFePO4 cells used in his arrays. Li Ping has always maintained there isn't a LiFePO4 cell made anywhere in China that he is not aware of, or has not tested for suitabilty. Given this, I think it's unlikely that better cells than his are available.

It has always been believed, the reason his batteries are so reliable, is his deep understanding of how the cells perform, and this is why he designs his own BMS. In fact, I would think the reason his batteries are so successful is due mainly to his management system.

m

[Burgerman]

Because people are ignorant.

It isnt possible to design a BMS that works CORRECTLY for:

a) ANY 2 different applications. For a list of reasons there isnt room for. + A BMS is only needed if you are ignorant of batteries and to save you from damaging them through this ignorance, due to lack of C rate for the applcation, or through early/late low volt cut off since they dont know the load.And:

b) to balance cells to a high degree of accuracy during the last part of charge. LiFe cells really dont like over voltage. To do that Accurately needs an integrated charger/balancer. Not a BMS and a dumb charger. It absolutely must be logic controlled, and never allow a cell to go higher than thour charge voltage. ALL passive non integrated BMS balancers allow cells to exceed this when charging as the balancer cannot slow down the charger and cannot sink enough current. Typically just .1 to .3 of an amp... While the charger is piling on real amps. Many allow 3.9 volts. plus or minus a huge amount! Equals very short cell life in many applications. Like tens of cycles instead of thousands.

[Burgerman]

I wanted to test pings using the powerstroller , but how easy are they to open or safe ?

If you have to ask this question then I suggest you do a lot of reading and hands on electrical/battey experience.

Its PERFECTLY safe if you know what you are doing. Like everything in life. Knowledge is power. To a bomb disposal guy, fireworks or even bombs are perfectly safe. To someone that knows about a car brakes, repairing your own or designing your own is perfectly safe. Its absolutely NOT SAFE if you have little understanding about any of this.

If you (not you personally!) have little understanding about most things in life, from housing, repairs, money, cars, you just get get ripped off at every turn, by those, that are making a living out of your ignorance. Basic universal BMS systems fall into this category. They keep a lithium battery working (all being well) for long enough to escape replacement...But often not successfully. .

If you know little about most things in life, everything "fails" or "goes wrong",and its someone elses problem. EG the countless "experts" that still advise ignorant punters to run their wheelchair/scooter batteries dead flat before charging! Because of some mythical "memory" that the totally different NiCAD batteries in question, NEVER HAD anyway! Then they sell them some CHEAP short lived batteries to replace the failed good ones... These sort of people pay through the nose for every thing to be replaced or repaired, and usually blame others for everything that goes wrong or just claim x batteries are crap... They do this with everything in life and then wonder why they are poor and nothing works.

Ignorance of physics, mechanical things (which is most of life), batteries, cars, houses, finance, business etc etc, means you live a life with little control over what is happening or knowing why and have no understanding of why things are not working out well and why you are poor (or immobile) with huge debt and no real hope.

On the other hand, some do just the opposite. And study and learn and understand the world, and make life and everything in it, work well for them both mechanically, financially and in our case mobility wise. But most people, the great majority, do not. They just make endless bad (stupid?) choices. Most people however are somewhere in the middle. With enough knowledge to stay afloat and keep out of trouble just about and no will to learn!

The people using ping batteries fall into this middle group. There is a cross section obviously. But those that know about lithiums, and BMS systems, wouldnt bother with them. Because they can see the issues of dumb chargers and universal one size fits all badly designed systems with cheap BMS. So those people, like me, are not a part of the discussions saying how good ping is. They (I) moved beyond that already so never went there.

Its kind of like having a 14 year old baby sitter, or a fresh 16 year old apprentice mechanic looking after your car. You might get lucky. Or more likely you might not. Better to learn, and do it properly yourself.

[snoko]

Because people are ignorant.

It isnt possible to design a BMS that works CORRECTLY for:

a) ANY 2 different applications. For a list of reasons there isnt room for. + A BMS is only needed if you are ignorant of batteries and to save you from damaging them through this ignorance, due to lack of C rate for the applcation, or through early/late low volt cut off since they dont know the load.And:

b) to balance cells to a high degree of accuracy during the last part of charge. LiFe cells really dont like over voltage. To do that Accurately needs an integrated charger/balancer. Not a BMS and a dumb charger. It absolutely must be logic controlled, and never allow a cell to go higher than thour charge voltage. ALL passive non integrated BMS balancers allow cells to exceed this when charging as the balancer cannot slow down the charger and cannot sink enough current. Typically just .1 to .3 of an amp... While the charger is piling on real amps. Many allow 3.9 volts. plus or minus a huge amount! Equals very short cell life in many applications. Like tens of cycles instead of thousands.

Perhaps then its just a case of choosing the best from whats on offer when they rave about Ping - like best rated B movie ?

Endless Sphere has lot of mechanics , engineers -even astrophysicists and lord knows who else who dont come across as being ignorant or naive, and yet ive never heard anyone say Ping or his system were as bad as you say or bad mouth it , so it really caught me off guard . ( i am not disagreeing with you just making an observation from my time there 2 yrs ago )

I noticed you also purchased it from it too - so I assume you must of thought so too ?

snok

[snoko]

I wanted to test pings using the powerstroller , but how easy are they to open or safe ?

If you have to ask this question then I suggest you do a lot of reading and hands on electrical/battey experience.

http://www.motoredbikes.com/showthread.php?35737-Help-with-dead-cell-in-Ping-battery

Or I could gaze into my youtube ball..

snok

[snoko]

What do you think about just using a cell phone charger to speed up ballancing by charging each cell group directly ?

Seems like an ideal poormans solution to if you had something like a weak charger...

The ping reassembling doesnt sound too hard Id just be removing those tabs with my dremel . splitting the pack in half , retaping and soldering balance / power wires , connectors.

snok

[Burgerman]

a) they all maybe use a common "ground" and if so there will be smoke.
b) a cell phome charger charges at around .3 to .5 of an amp, so would take 60 hours minumum to charge just a 20 Ah battery and it would likely never end since self discharge rate at the full charge voltage is too high.
c) a cell phone charger is typically 4.2 volts, for lithium ion cells, as is my camera, laptop cells etc. We need 3.6.

You could use some bigger single cell hobby chargers, as long as they had a FLOATING OUTPUT and were not tied internally in any way. But then you have just as many wires, and 4 chargers. How is this better than one charger with balance connector?

[snoko]

a) they all maybe use a common "ground" and if so there will be smoke.
b) a cell phome charger charges at around .3 to .5 of an amp, so would take 60 hours minumum to charge just a 20 Ah battery and it would likely never end since self discharge rate at the full charge voltage is too high.
c) a cell phone charger is typically 4.2 volts, for lithium ion cells, as is my camera, laptop cells etc. We need 3.6.

You could use some bigger single cell hobby chargers, as long as they had a FLOATING OUTPUT and were not tied internally in any way. But then you have just as many wires, and 4 chargers. How is this better than one charger with balance connector?

Maybe im wrong here ( but from what the way i interpreted it ) that guy Ypedal was talking about it using it to " top them off " not as replacement for balancer / charger - but in addition to it.

I noticed he said he hadone of these, so it I assume thats what he meant otherwise - as you say - it would make no sense at all.

The BMS has resistors that drain power from the fully charged cell groups while the low one's catchup, the problem is that this happens in milliamps ( ie: SLOW.... )

Using a cell phone charger can speed up ballancing drastically, by charging each cell group directly via the ballance leads or the cell terminals directly you can get the job done way faster.

WARNING : most cell phone chargers will want to charge to 4.20v, your ping pack has lifepo4 cells that will be fully charged at 3.65v .... so using a regular cell phone charger you need to keep an eye on things and pull the plug at 3.6v.. it's ok if it goes up to 3.9v.. and not a huge deal even if it does hit 4.2 but try to prevent it.

snok

[Burgerman]

The BMS has resistors that drain power from the fully charged cell groups while the low one's catchup, the problem is that this happens in milliamps ( ie: SLOW.... ).

Yes the BMS systems are crap. However the HYPERION drains the cells during balance at a third of an amp. So as long as they are reasonably well balanced to begin with (after the first charge which may take days) then all subsequent charges should end in just a few minutes without ever sending a cell over 3.600v. The BMS cant do this and allows the charger to push the cells over the safe voltage. It cannot slow the charge rate.

Using a cell phone charger can speed up ballancing drastically, by charging each cell group directly via the ballance leads or the cell terminals directly you can get the job done way faster..

He means to add some power, temporarily, to each LOW cell, to bring it up to mactch the others. This needs skill and an accurate volt meter. I f he used decent cells, anbd a hyperion, then it does all that for him...

WARNING : most cell phone chargers will want to charge to 4.20v, your ping pack has lifepo4 cells that will be fully charged at 3.65v .... .

LiFe cells, like headway or ping or A123 etc live longest and suffer least damage if kept between 2.7 volts and 3.5 volts. The makers say 3.6 volts, or 3.65 volts because this is ABOVE the full charged point, and so affords faster charging and some measure of "natural" cell balancing. In other words its too high, so all cells get overcharged a bit. This means all are full and its faster. However this shortens service life as one of the plates gradually gets coated with lithium metal. So if you use a GOOD charger, that can HOLD the cells at say 3.45v to 3.5v for an hour at the end of charge, then it assures a full charge without going over 3.5v. Crappy BMS and dumb chargers just charge till you "see" 3.65v and then stop. In the process some cells may be over 3.7 or so volts! Not pretty.

so using a regular cell phone charger you need to keep an eye on things and pull the plug at 3.6v.. it's ok if it goes up to 3.9v.. and not a huge deal even if it does hit 4.2 but try to prevent it.

Totally wrong. Service life and cell health depends on terminal voltage to a large degree. These types of chargers, and cheap BMS systemss that allow cells to exceed 3.6v are the reason we hear so many horror stories about failed lithium cells.

[snoko]

i can imagine the look on some of their faces if you went there and handed his ass to him a plate like that ( hes a mod on ES too - and HIGHLY respected !! )

I think they did do have pretty big thread on your Hyperion over there actually , and more than few of them mention using 2 or more of these switching psus called meanwells these things as power supplies.

Ive heard theirs a lot more risk of damage using these ( in addition to the noise ) , but unless Im using 2 or something would that really be a problem given how much the Hyperion can handle ?

snok

[snoko]

To Goose ( a small update )

I couldnt get the 12mm rose joint to fit and the 13.7mm is a 1mm or so lose perhaps - not a big deal if it tightens up well ( they never sent me the screws ) but the weld joints means bit less room than i thought. ( 11mm if you)) add the other joint )

the only rod end I can find that is small enough is 12.7mm bore size and 11.5 ( unless theres smaller ) and is also going to require me to use washers that have a very small radius ( if they even exist ) in order to make the space available -perhaps an m8 bore with 3 mm radius to make up the 12mm diameter of the bar..

snok

[Burgerman]

http://batteryuniversity.com/learn/arti ... _batteries

This relates to lithium ion cobalt rather than lithium ion phosphate or lithium ion polymer. So not 3.6 but 4.2v cells. But the exact same thing applies to LiFePO4 cells although that site is a bit out of date.

Note on graph what going over the cells voltage does to cycle life
This is why the hobby industry use balance chargers and exact accurate cell voltage control.

What kills lithiums?
Over discharge.
Too high C rate discharge.
Too high C rate charge.
Heat. Cooler is better.
and the biggest one? OVER VOLTAGE...

These are 3.7v lithium ion cells. So should be charged at 4.2v. LOOK what happens when they go over by just a tenth of a volt!!! Now you see why I charge my LiFePO4 cells to 3.450v EXACTLY? Because 3.600 volt adds under a quarter of 1 Ah. And means a shorter life. Lithiums live forever if kept cool and away from full or empty. Over 3.600 volt is damaging for LiFePO4.

[snoko]

http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

This relates to lithium ion cobalt rather than lithium ion phosphate or lithium ion polymer. So not 3.6 but 4.2v cells. But the exact same thing applies to LiFePO4 cells although that site is a bit out of date.

Note on graph what going over the cells voltage does to cycle life
This is why the hobby industry use balance chargers and exact accurate cell voltage control.

What kills lithiums?
Over discharge.
Too high C rate discharge.
Too high C rate charge.
Heat. Cooler is better.
and the biggest one? OVER VOLTAGE...

These are 3.7v lithium ion cells. So should be charged at 4.2v. LOOK what happens when they go over by just a tenth of a volt!!! Now you see why I charge my LiFePO4 cells to 3.450v EXACTLY? Because 3.600 volt adds under a quarter of 1 Ah. And means a shorter life. Lithiums live forever if kept cool and away from full or empty. Over 3.600 volt is damaging for LiFePO4.

I never realised how little margin for error there was till I saw that , they literally divebomb ! -thanks

Makes me wonder how the hell Ypedal guy became a mod - he must have some good connections over there and few gallons of koolaid .

So whats your opinion on that 400w meanwell I linked too ?

snok

[Burgerman]

Their error / confusion is because...

Yes. A few tenths too high on one cell, and it ruins it. Treated properly a lithium Phosphate should last thousands of cycles. Treated badly maybe 20 times less. Hence my dislike for built in or universal BMSboards...

Take a seat.

They use dumb chargers. They charge at X amps, until they see their 3.65 volts (or 4v or whatever they think is working best, at X amps for say 4 or 8 cells. Then the dumb charger stops at when it drops to say 1 amp. Or when it sees 3.8v per cell. The cells may well be out of balance with some at 3.7 or 3.9v and others 3.4... Then because the cells and wiring all have resistance, the ACTUAL cell voltage drops fast to what it REALLY is. 3.35 to 3.6 etc. They THINK its charged and balanced, and its not - but it has spiked to a higher than manufacturer specified figure at least on some cells.

The hyperion charges each cell to EXACTLY what you choose, say 3.650 as Headway suggest, or if you have more sense a little less like 3.450v. It FULLY charges the cells to exactly this voltage and never goes higher. And soaks them at this voltage until no more current flows in at all. This may take an extra hour or 3 in some cases. So at 3.450v you get a PROPERLY full charged cell, has never seen the higher voltage spikes, and ends up actually more charged. And EVERY cell ends up identicaly charged to within 3/1000ths of a volt.

They dont understand what is actually going on and are all advising each other. Remember that half the population are below average intelligence by definition. And that 90 percent are in the "normal" range, meaning they understand almost nothing. But they all advise!

[Burgerman]

The link goes to a cheap and nasty 10 cell charger?

I have spent 3 years and endless firmwares testing and developing and helping/advising to get the hyperion charger as good as it is. So wouldnt and couldnt recommend anything else. Because I know how crappy most are!

[snoko]

The link goes to a cheap and nasty 10 cell charger?

I have spent 3 years and endless firmwares testing and developing and helping/advising to get the hyperion charger as good as it is. So wouldnt and couldnt recommend anything else. Because I know how crappy most are!

Well, I wasnt planning to use it as a charger if you mean this one

Just purely as a psu.

snok

[Burgerman]

They make a 24v 480 watt version. I have one. It allows you to use about 70 percent of a 1420 hyperions capability.

1420 Hyperion operates from 9v to 29 volt. It operates at maximum power (550 watts output, 650 watts input depending on output voltage) on 24 to 29 volts. With a 12v supply it can only give about 2/3rds power.

So best to get a 480 watt 24v version, and adjust its "voltage screw" to maximum. Which is about 27.2 volts. Looks exactly the same. That way you can charge your 12v pack at 20 amps.

[Burgerman]

http://www.ebay.co.uk/itm/MEAN-WELL-PSP ... 2c699e33e6

http://www.ebay.co.uk/itm/MEAN-WELL-HRP ... 4d06b3a826

[Burgerman]

http://www.ebay.co.uk/itm/MEAN-WELL-HRP ... 4d06b3a826

24v 47 amps. Perfect for any future project.

Or 480 watts as I have here http://www.ebay.co.uk/itm/MEAN-WELL-SP- ... 3cc8b085d5

[Burgerman]

http://www.powerstream.com/lithuim-ion- ... oltage.htm

Heres another test. Cycle life ABSOLUTELY depends on charge voltage. This test relates to Lithium cobalt, lithium polymer (shown results) and lithium phosphate.

The Polymer cell tested is "full" at 4.2v The Cobalt cells are "full at 4.1v. The Phosphate cells are "full" at 3.6v. Actually they are 99.5 full at 3.450v tested on my bench for capacity.

Look at the effect of cycle life in the chart of charging to a lower voltage. And read the part about lithium plating at the top...

Now tell me the expert on that other forum has any clue?

http://www.powerstream.com/lithuim-ion- ... oltage.htm

[Burgerman]

Note all lithiums behave in similar fashion. This test was on a lithium polymer hence the 4.2v correct charge voltage. Instead of 3.6 volts.

But the same thing happens on LiFe cells too. So best to undercharge a little, for extreme battery life than to overcharge. You lose a tiny bit of capacity, but its under 1 percent on LiFe cells. Cheap built in BMS systems like the one in monoblock batteries or ping, allow overcharge to about 4 volts or more if used on a dumb charger...

[snoko]

They make a 24v 480 watt version. I have one. It allows you to use about 70 percent of a 1420 hyperions capability.

1420 Hyperion operates from 9v to 29 volt. It operates at maximum power (550 watts output, 650 watts input depending on output voltage) on 24 to 29 volts. With a 12v supply it can only give about 2/3rds power.

So best to get a 480 watt 24v version, and adjust its "voltage screw" to maximum. Which is about 27.2 volts. Looks exactly the same. That way you can charge your 12v pack at 20 amps.

I just saw 2 x 24V DC 14.6A for £60.00 (including delivery ) earlier on which seems a good deal - just more hassle in terms of wiring them together perhaps

That would give me 700 w ( 150 - 50 watts more than i need ) but is that going to be a problem in terms of overheating ?

snok

[Burgerman]

How are you going to connect two 24 volt power supplies? Unless set to the EXACT same voltage only 1 will provide all the power, the other will be idle. If you are going to mess about joining two together (and I wouldnt) I would use two 12v ones in series. But then there are isolation issues...

Better to get one that is adequate.

[snoko]

They mention using 2 of these in parallel here (if your interested )

Having to use separate supplies, to power each charger, is a non-issue, in my case, because in order to get the full 550W out of the 1420i units, you need a supply that can put out 650-700W, and they need to be about 26-28V. By far the cheapest/most readily available MW options are the SP-320-24 and S-350-24 models. For bulk charging my 24s3p setup I've been using four S-350-24s, wired in series. Now, with the Hyperion chargers, I just split the four into two pairs, and wired them in parallel so that I have two setups that can each put out about 26A at 27V. Each of these are then used to drive a 1420i.

This is where I saw them cheap

snok

[snoko]

How are you going to connect two 24 volt power supplies? Unless set to the EXACT same voltage only 1 will provide all the power, the other will be idle. If you are going to mess about joining two together (and I wouldnt) I would use two 12v ones in series. But then there are isolation issues...

Better to get one that is adequate.

I dont know , but according to that guy on there ( gary ) he says he has ,so I assumed it was - or at least might be, why else would he say otherwise ?

snok