S646se - Full LITHIUM Pack Project - First Attempt

[expresso]

They may benefit from a few cycles exercise though esp if been stored for months. Regular daily use will likely sort them out though.

i keep the ride shorter then - just to get a feel - for a while longer till it warms up more - suppose to be nice here - but what others think is nice - i may still feel cold moving - alot of AB dont get it -

everyone is different also -

[Burgerman]

No just use normally. But be aware. Cold? We were up to 18 degrees, now suddenly iys 6 again! centigrade obviously.

[expresso]

i am done making my last two cables for the pack - the charging cable and the ADD ON Cable - very hard time making the charge cable again - - could have been me - not in the best of moods and decided to do it - i should have waited till a better day -

but its done - if it works - will be starting to test the Pack in a day or two - will use your Full Pack preset and charge first fully -

then discharge how much 30ah ? for the first time - then recharge again - and discharge 60ah ? recharge again - discharge 80ah - and recharge final time ?

sound about right ?

[Burgerman]

No need to do 80A.

[expresso]

ok i do 20 and then 50ah and see how it does -

[expresso]

1st charge -- discharging now

[Burgerman]

What is the termination set to? It looks OK but I dont remember...

I remember 133rd C so, about .780A or 780mA?

May be better at half that. As long as it doesent sit for hours at the top voltage. Try it after a discharge/top up at 500mA. If that ends fast, 400mA etc.

This will get closer together after 3 or four cycles. download/file.php?id=4951&mode=view
Until its one line almost.

[expresso]

its set to 700 termination - when this discharge is done - i will stop it around 4pm - should be about 20ah discharged by then - will change it to 500 Term. and charge -

then disharge it again tomorrow morn. - and recharge again - resetting the term. if needed to 400

glad its working - now i have to get my chair ready - hopefully over the weekend - and then wait for someone to put it in there

[Burgerman]

Then you can to that bridge and back, and go again for another go...

[expresso]

yes i agree - it can be done - now the big thing is this - Now that i know it can be done - and i done it - almost 90% - it was a Really Long trip - i did get tired - depends on my mood that day - i will do it - but may just take the bus one way there

take me close to 177 st.. on the east side - then i just cross over to the west - do the bridge and back - and come back on the west side along the river - that can be done now with the ADD ON chair - being that i almost did it with out the bus -

i know i can just ramble around the city now - where ever i like and not worry about battery life - i never am going to get down that low - with the full pack - i mean 35 to 40 miles - thats maybe 8 hours of non stop full speed riding

whos going to do that - - i can make it to the bronx and back to my older area - battery will make it - if i make it is another story now - not great scenary going there so not worth it really - too long - and have to dodge some bullets - who knows haha

i just seen the news here - they made a huge drug bust on the very same block i was on the other day in the city - 102 street and 2nd ave. - day time its not as bad - i woulnt be there in the night time

[Burgerman]

Well that was the goal. To go wherever you want, never even look at or need a battery meter.

Because almost every truly ACTIVE user has one eye on it, and subconciously learns to limit his activities or days out and so lower expectations over time. So you end up thinking range is adequate, when in fact, you have learned to comply.

So even many of those that will tell you that lead has enough range for them and they always get home actually are still restricted. They just learned what to expect and plan days accordingly. Last year it took me a year to throw off this worry! Only going on a couple of stupidly long days out and not seeing that battery gauge move one bit, can get this out of your head.

After that you just feel free. Liike the chains are gone! No more worry. If YOU can do it, the chair just does!

One warning. When you start to lose greens, and see orange, and start losing these too, you better stop. And this will happen fast right at the end with little warning. Compared to lead. Dont drive it till it stops and even if you try it will be about a mile further. When you start losing lights fast its over.

[expresso]

the way i seen the ADD ON working so far - i didnt loose a green till about 20 miles - i dont think i ever see a green lost with the Full pack - unless i dont charge for a week and use the chair normally each day - then i will -

or else - its a thing of the past - and thats what happens - you get trained to accept what lead gives you and thats it - you may think you dont need more range - but you know from the start of your day - what you can do or not do with lead - so you plan your day around that - with out noticing it - and maybe even carry a charger - which is useless unless its at least 20A model - to get some juice back in a short time -

i am used to Lithium already - i notice the change when it goes into the lead after a good 15 miles or so - the feeling changes up hills - not as snappy etc, - its ok - just like before - just now i know how much better it can be - should be -

[expresso]

first discharge 20a - changed to 500 term. and will restart charge

tomorrow will discharge once more to 40ah - and recharge again - that should be good - get the chair ready - wait for help to install it - done

[Burgerman]

YEP... 20Ah is enough. 40 achieves nothing extra (unless to store the battery in a healthy state).

You see how flat that 20Ah out is? Once the first few Ah are used. From 2.7 hours onwards? That cell line(s) as you are discharging? download/file.php?id=4953&mode=view

Thats why you cant use volts to tell you the state of charge. And that will continue to at least 40Ah at that level voltage. Its also why battery meters and the "fuel tables" in that charger cant work on lifepo4.

And you removed 20.87Ah. When you recharge you will put only a tiny bit extra back. Because lithium is far more efficient than lead. Maybe an extra Ah? We will see. If it was lead you would put back much more extra.

[expresso]

yes i see how it works now - its perfect in terms of discharging rate - etc, this is due to the fact that the Cells were grouped correct- thanks to Scollard - getting them as perfect as they can be -

so when i use the chair - no matter how much i drain - i will charge up fast and balance in the end fast and full - at 35A charging- even a deep drain would bring it back to full in short time -

i most likely be done charging before i go to sleep - which is great - unless i use it at night also - in which case - would leave overnight - or i may just swap chairs while one is charging - either way - one will have to charge overnight if thats the case - in the summer - i dont mind going out at night etc, - its nice -

all depends how i feel - if i get exhasted in the day - i like to eat - drink and rest with music after -

[expresso]

YEP... 20Ah is enough. 40 achieves nothing extra (unless to store the battery in a healthy state).

You see how flat that 20Ah out is? Once the first few Ah are used. From 2.7 hours onwards? That cell line(s) as you are discharging? download/file.php?id=4953&mode=view

Thats why you cant use volts to tell you the state of charge. And that will continue to at least 40Ah at that level voltage. Its also why battery meters and the "fuel tables" in that charger cant work on lifepo4.

And you removed 20.87Ah. When you recharge you will put only a tiny bit extra back. Because lithium is far more efficient than lead. Maybe an extra Ah? We will see. If it was lead you would put back much more extra.

so i dont need to discharge again just to test it - one more time ?

BM did you get the email i sent you - the response i got from PG - about battery settings etc, on the Rnet - ? just curious you didnt mentioned it - wonder if i sent it to the correct email

[Burgerman]

i most likely be done charging before i go to sleep - which is great - unless i use it at night also - in which case - would leave overnight - or i may just swap chairs while one is charging - either way - one will have to charge overnight if thats the case - in the summer - i dont mind going out at night etc, - its nice -

With lithium, and the huge range and powerful charger you dont need to charge at night. I do it next to my PC while checking mail etc.

Most days you will use about 1/3rd the charge. So you can put ALL of it back in an hour as you surf. Or just part of it and leave it a couple of days. Or not bother at all for a couple ofdays and charge it full as you watch a movie...

The point is that even if its half empty it will still take you 20+ miles... And you can put it back at the rate of 15 miles ( A typical day hard use) per every 1 hours charge!

Its even advatagous to do this, lithiums prefer not to be full, or empty. And last forever if you keep them in the "middle". You only need do a full charge to accurately balance maybe weekly.

Its all up to you.

[Burgerman]

so i dont need to discharge again just to test it - one more time ?

Yes take 30Ah out. If it all looks OK, when charged back up, then take 30 out again and leave it. Its best not to leave it full if you wont be using it within a couple of days.

My email isnt web mail. And its on my desktop PC and thats off. I am on a bed. No email!

[expresso]

ok - i will do that then - since it wont be a few days till i get it in the chair for real - have to get it ready - and figure how to attach the charge cables to the chair so it wont move -

oh ok - the email i got back - was from the engineer - he was very helpful in explaining everything - if i only knew what it all means - thats another story - but you may understand it -

i will copy past it to you in PM -

[expresso]

i lowered it down to 400 term. for the next recharge -

discharging now - till i go to sleep - will continue to discharge a bit more tomorrow till i get 30ah to 40ah out - and recharge again to see how good that 400 mark is

[Burgerman]

Well its all balanced, and 99.5 charged. I would try 250mA and then if it ends correctly leave it that way.

[expresso]

ok - will change it before i recharge it tomorrow -

[Burgerman]

As you can see, even charging at 20A it charges at full power right up to the last couple of minutes. Unlike lead, which starts to drop away, then takes 4 or 5 hours.

This is why you can charge these fast. You dont need to change it to 250mA, if you dont want, its actually done ALMOST 100% now. Unlike lead it doesent benefit from being held at 3.600v for a long time other than it gives a chance for really fine cell balancing. Which isnt that critical. And they are spot on anyway at the moment.

[expresso]

i will change it to see - and its charging at 35A on the full pack preset

[Burgerman]

download/file.php?id=4955&mode=view

Not according to the graph. Its SET to 35A but charging at 20 ish Amps. So you must have it set to less than max Amps on the SUPPLY tab. It is set to protect a smaller supply possibly. And set the volts to 10V minimum. (lower limit). So it can run from a car, or powerchair or power supply as needed.

My other guess was about right. You put 1Ah extra back. That would have been 4 or 5Ah extra if lead!

[expresso]

oh yes your right - its set at 25A max in the supply - for the Lead -- i have to change that - so it can do the max if i choose -

you want me to set it down to 10V ?

i will make the changes before i recharge

[Burgerman]

Yes. Or if you ever connect to say a battery in a car to top up your chair to get home, or whatever it will not allow it...

If you set the min voltage to 10 it will work from 10v to 32 volts.

If you set max Amps, to say 10, it will never try and take more than that. So you can use a small power supply that is easy to carry on hols or whatever. Or a cigar lighter socket in a car.

[Burgerman]

Read the manual!

[expresso]

Read the manual!

yes i get it - i have read it briefly at first - the basics -

needed to charge from a Car - thats nothing i will ever need - at least that i can see for now -

one thing - lets say - i needed to charge and i am not home to use the Pl8 - if someone had a dumb charger 28.8V and use in the joystick -

that would work - but just wont balance anything - etc, - this is what if - i dont think i ever run out of battery now just curious if thats fine to do till you get home and use the PL 8 - to recharge the right way -

its alot easier to carry a small dumb charger than the PL 8 and PSU etc, less to worry about etc, -

[Burgerman]

You can charge as a dumb lead battery as long as its only up to about 3/4 full...