PINNED - Lithium battery conversion/info

[expresso]

The pack is ready for the first ride test.

2017-10-27_1003.jpg

you did good - chair frame looks very silimar to quickie sunrise 636 models 646 chairs at least from the rear - i see you have the charge cable inside - are you going to open the rear battery unit to charge it each time or mount the cable outside on the frame - once your satisfied with the performance

[Gnomatic]

Looks good snaker. Looking forward to reading about your first impressions.

[snaker]

Ride test #1 PASSED

I ran around my small city. Total range is 25.6km, the pack worked fine. After the trip, its voltage was 26.5V as expected. The electrics are actually cut off this morning, I have not charged it yet. I will charge it in the afternoon and post its charging graphs.

Here is my first impression. Comparing to my old 50Ah plug-and-play pack, this 150Ah pack appears a little stronger in voltage. It makes the chair a little more jerky and aggressive. It needs to be reprogrammed a little. I also felt the chair was faster. I will measure its accurate speed later in next ride tests to check out how faster it is.

The border to Laos (a neighbor country) is only 70km from my house. My chair consumes about 1Ah/1km. So in theory, a 150Ah pack could take me to Laos and back home. I did not ever think to bring belong a toilet roll before but now I seriously consider it as a MUST. BM appears having many experience for long rides

[snaker]

you did good - chair frame looks very silimar to quickie sunrise 636 models 646 chairs at least from the rear - i see you have the charge cable inside - are you going to open the rear battery unit to charge it each time or mount the cable outside on the frame - once your satisfied with the performance

The charge cable with a female DSub is stuck and fixed on the battery box. When charging, my dad just plugs another one with a male DSub. My chair is a cheap Chinese. It's far to meet the quality of Quickie or Invacare. Its only good thing is the speed 12.75km (measured).

[snaker]

I bought these silicagel balls. They are cheap, a 100g bag costs only $0.5. I will throw 2 bags into the battery box to prevent humidity. Have anybody here used them? How good/bad are they?

[shirley_hkg]

Average speed @12.02 is very good . I usually couldn't reach that , thought chair hits 16kph on straight course .

[snaker]

Average speed @12.02 is very good . I usually couldn't reach that , thought chair hits 16kph on straight course .

HK streets are always busy. If running too fast, you can hit an ... airplane

Sometimes I drove like mad in empty roads in countryside. Avg speed of whole trip reached 12.7Xkph.

[Burgerman]

Dont charge yet. Go out again...

And silica gel is only a sponge. It absorbs water from the air, and stores it. After a day or so its fully saturated. So will then do nothing. So you will need to remove it every 2 days, and dry at 80 or 90 degrees C in the oven for an hour. So basically its pointless.

[Burgerman]

1Ah/1km

Sounds very low? You must be light?

[snaker]

I charged the pack. 29.5Ah was returned. Graph seems fine (expert cell 6 ).

[Burgerman]

When you discharged it, you got 135Ah?
So to be safe call that 125Ah. Then you will never discharge too deeply, no worries about cell 6...

So you went 25km on 30Ah returned. Thats about 28Ah actually used, since you always put more back that taken out. (battery not 100% efficient).
So you actually get 25km per 28Ah. You have 125Ah safe usable, so you went 1.12km per Ah. (thats very efficient compared to most chairs)


You can go 1.12 x 125Ah = 140km. Or 86 miles safe range Expresso will be jealous.
(With a 20Ah addon, you will have another 22+ miles, so 107 miles or 172km range.)

(With 11 miles safety reserve till dead... IF your figures are accurate).

[LROBBINS]

But do remember that maneuvering around indoors or on difficult terrain will drain it faster, but it does seem that you have tremendous range even leaving an extra-safe margin.

[Burgerman]

0.6959357 mile per Ah.
Or...
.7 mile... Approx.

So 100Ah is 70 miles. You must be very light.
I get about 2.18Ah used per mile. But 21 stone. (130kg) or 46 miles to 100Ah.

You are getting 40% better range per Ah.

[expresso]

thats great if you can get 86 Miles out of the chair - you would need about 12 hours nonstop riding to do that - means you never reach the bottom of that pack in a days use - or maybe you can do it - either way its a great feeling to know you have the range now -

speed your doing about 8 mph - up to 10 mph - speed isnt bad - thats good speed - most chairs here dont go that speed -

for an indoor chair only - like one i am using - even a 75ah pack with these cells - means i need only 8 Cells - would be a great upgrade and easy to do - maybe its something i can consider one day down the line - instead of buying new lead for the chair - even cheap lead would cost more than 8 of those cells -

its the shipping thats the downside -

[Gnomatic]

for an indoor chair only - like one i am using - even a 75ah pack with these cells - means i need only 8 Cells - would be a great upgrade and easy to do - maybe its something i can consider one day down the line - instead of buying new lead for the chair - even cheap lead would cost more than 8 of those cells -

Probably not a good idea. Indoor only chair, meany high amps only on the battery. These cells, low C rate. Won't last long like that. Not as big of a deal if the pack is 150Ah.

[expresso]

for an indoor chair only - like one i am using - even a 75ah pack with these cells - means i need only 8 Cells - would be a great upgrade and easy to do - maybe its something i can consider one day down the line - instead of buying new lead for the chair - even cheap lead would cost more than 8 of those cells -

Probably not a good idea. Indoor only chair, meany high amps only on the battery. These cells, low C rate. Won't last long like that. Not as big of a deal if the pack is 150Ah.

oh ok didnt know - i figure it would last for ever - i mean when i say indoor - its only indoor for real - and not always in it - ususally on my computer - not in the chair - or recliner - even if i added a Small ADD ON to the lead - it should last many years that way even with crap lead or used lead - ?

things change - i may at some point have to get rid of one chair - what sucks is - i feel best indoors with the indoor chair only - the others its not the same -

[Gnomatic]

I gotcha. At this price, tempting to take a flyer on a set.

[expresso]

I gotcha. At this price, tempting to take a flyer on a set.

i am just thinking about my options later on with this Indoor chair i use - i will have to change the lead at some point and may have to buy them this time around

i dont really care to fill the chair fully - its never going to be used for outdoor usage or riding etc, - i bet i could even make a 45ah pack and stick that in the chair and i bet thats even fine - for the light usage it sees - i could charge that once i week i bet - but not sure its even worth it in the end - may not even keep the chair at some point - i plan to keep it as long as i can since i feel best in this 15 year old chair indoors -

for the cost and if shipping wasnt so high - it would or may be worth it - or else cheap lead and use it as is - i actually still have a set of PC 1500 lead here -
they didnt fit as good - had to be forced in i recall - i used them for one summer before removing them for MK gel and the 36ah ADD ON -

i keep them charged once a month - i saved them in case of black out - another set of MK also i have sitting for that purpose - i check and charge once a month - maybe at some point i can just use those MK instead - and keep going with the Lead in this chair only -

[Dogsbody]

Hi again,

Just wondering what the current situation is for shipping lithium cells from Hong Kong to the rest of the world if anyone knows?

Hoping to get some from taobao..

Cheers,

Dog

[Burgerman]

Dependswho is shipping. Evassemble, no problem.

[snaker]

Test #2 PASSED

It was 59km/12.68kph/64Ah. The app "My Tracks" deleted all data after upgrading its new version so I cannot up the statistics sheet.
https://drive.google.com/open?id=17oNq- ... sp=sharing

I am looking for a 100km route for the test #3.

[expresso]

nice - how long did it take - how many hours ?

[snaker]

I actually weigh about 50-55kg. Before being disabled, I was still considered as a grand guy, bigger than other guys around

Yes, this chair is a surprise about its efficiency. It's 40% more efficient than my old 8kph chair too. I used to run up to 51km (measured) with my old 50Ah (only real 45Ah) pack.

I am still confused about the C discharging rate? Does it apply to the whole pack capacity or only the remain capacity? E.g a pack has a real 100Ah and 2C discharging rate. If it is full, it can be safely discharged at 2x100 = 200A. But in case it's not full (say 10Ah left), can it be still safely discharged at 200A or only 2x10 = 20A?

[snaker]

nice - how long did it take - how many hours ?

Yesterday I ran continuously in 04:45.

I expect that my next trips would be always 70km or more. That means around 6-7hrs on roads. The urine bag would become a big problem. It could explode after that time

[expresso]

now that you have all the range you can use in a day - creates other problems

you do have good milage - if i do 40 Miles - i return about 85Ah to 90Ah back when recharging -

you returned 65Ah and did 36 Miles - you shouldnt get low enough to worry about Cell 6 - i dont think - now next thing you need to do is get a camera to video the ride -

[Burgerman]

E.g a pack has a real 100Ah and 2C discharging rate. If it is full, it can be safely discharged at 2x100 = 200A

Without rapidly killing it yes, its a max possible number, but it will still be unkind to the battery and severely shorten service life.

So at 2C you my get 100 to 200 cycles.
Same pack at 1C andyou should get 1000?
Same pack at half of 1C and maybe 2000...

And remember that ramps or curbs, steep hills, and turn in place, may take 60 to 100A per motor intermittently.

[shirley_hkg]

[Dogsbody]

Shirley,

I call you out to accuse you of battery pron.

Jealous... (very)

Looks like great work..


Dog

[expresso]

drunk2

Nice - you tested the packs - how good are they ? where are you using these on - another chair ?

what size are those packs each ? 24V 90ah ?

[Dogsbody]

Looks like an 8s9p, for a 135ah 24v pack in 2 12v blocks...