Lithium capacity tester

[Burgerman]

Capacity wiill improve some if cycled half a dozen times after being stored. That extra little connector Allows an external power Supply like a RC Battery pack to power the watt meter in the event that your power supply or cell is below 4.8V.

[expresso]

oh the 3 pin connector -

i am just about done recharging it up - it looks like 90ah put back in - i will start another discharge after its done - and go to sleep

its taking a while to finish up - i know when in use daily - its balances fast - 15 mins maybe at most - now its taking a long time compared to when in daily use

i expected that - its common on my other chairs also - over the winter time - and now having all my outdoor chairs lithium - i cant use them all every day

[expresso]

i did it twice Capacity checked - full charge and full discharge - nothing really changed much - i am not doing it a 3rd time -

i would have a 90ah pack if Cell group 3 and 5 didnt drop faster than the rest - because they do - i am at 85ah - its fine for me for how i will use this chair for now anyway

now the question that came to mind is this

What if i am out riding and go more than it can do - meaning what if Cell Group 3 and 5 drop too low when i am out riding but the rest are still at 3.1 V or 3V


does the chair stop working - can it run off the rest of the pack if Cell 3 and 5 - drop below 2.5V or 2V - - i know if that happened most likely killed them and cant recharge them from being too low -

my concern is only - will the chair keep going - and what would it take for it to stop - do all cells have to reach below 2.5V ? or what if most cell groups reached very very low - but a few are still at 2.9V lets say -

is it like running off 4 cylinders as oppose to 8 - an example - -

if i run this pack for 30 miles - i would be at full discharge on this pack - Cell 3 and 5 would be fully down at 85ah - so what would happen - if i did 30 miles - i say this is good for 25 miles at this point with 85ah pack -

i know i always got around 30 miles and used 90ah - i think i pushed it the first year - doing 40 miles on the 105ah - i realized it after i had to change one cell - and added the 45ah extra for that reason after the first summer -

i crashed also that first summer after i added the pack

[Burgerman]

The chir stop based on the total voltage. So it depends on the adde voltage of all the cells. And I mean voltage whn under load. It my drop more under load when one cell voltage drops to zero or gets reversed when its totally dead. So its hard to guess.

[expresso]

its the total voltage i set in the settings ? Rnet - i adjusted the end voltage - have to see where it is actually dont remember

if it hits that voltage it stops ? but what if the total voltage dosnt hit that voltage - but some cell groups are low - or dead lets say -

as long as the pack volt is above what i set - it will just run till its below no matter if some cell groups are dead ?

this pack is 80ah now if stopped at 2.9V - so in use - its not a chair for long distance at all now - 25 mile range i say to be safe - which is still better than lead alone - but not by much now

this is why a small pack is never good for us - if this was a 200ah pack and i lost 25ah of the Capacity - it would still be 175ah after - still more than enough

since this started off as 105ah - which wasnt enough either from the start -

this was a pack that when used summer time really only - it was used mostly all the way down and up each time - i was still expecting more life out of it - but not complaining for what it did for me - freedom to just go and not worry -

now it will just sit and be a back up worse case use chair - just local

[steves1977uk]

I can get 30+ miles from a 75Ah pack due to my old modded chair being much lighter than today's powerchairs. I prefer to use this one over my new Dietz chair due to it being nearly half the weight. Weight is what murders batteries fast, especially Lead bricks.

Steve

[expresso]

thats great - not with my chairs - remember i have full tilt lift high speed motors

this pack is now 80ah - which is a bit more than your pack when new - after 6 years - so cant complain - yours would last much longer also - i used mines harder each time i used it - i always went down low -

and its still 2x better than lead even now -

[Burgerman]

its the total voltage i set in the settings ? Rnet - i adjusted the end voltage - have to see where it is actually dont remember

if it hits that voltage it stops ? but what if the total voltage dosnt hit that voltage - but some cell groups are low - or dead lets say -
as long as the pack volt is above what i set - it will just run tillits below no matter if some cell groups are dead ?

Obviously. It doesent know the individual cell voltages.

this pack is 80ah now if stopped at 2.9V - so in use - its not a chair for long distance at all now - 25 mile range i say to be safe - which is still better than lead alone - but not by much now

By DOUBLE.

this is why a small pack is never good for us - if this was a 200ah pack and i lost 25ah of the Capacity - it would still be 175ah after - still more than enough

since this started off as 105ah - which wasnt enough either from the start -

The bigger the better. For MANY reasons. And another reason those drop in lead brick replacements are a waste of time and money.

[expresso]

remember when i did this pack - back then - headway cells were the ones to use -only ones to use for us - this was the best Capacity to fit at that time -

now 200ah is the Norm. those 230ah and 240ah cells they are selling - with all the same physical size of the 200ah - i dont believe those numbers - if anyone purchased 230ah and 240ah and tested them - would be good to know what they really are -

by saying its 230ah and 240ah - can charge a bit more - when in fact they may only be 200ah -


or the other way around - maybe those 200ah cells were really 230ah and 240ah when new and are now only 200ah - and sold as 200ah -

how much can fit in the same physical size shell ?

[expresso]

i have to check the chair one day - but i think its set to 18V cut off - my pack would be dead if it ever reached that far - discharged down to 2.9V showed a 24.7V

at least i wont stop till the whole pack is dead

actually i raised that to 22V cutoff - i think it was the most i can use - if it reached 22V for use - the whole pack would be 2.75V each cell - and the low cell group 3 and 5 - 5 being the lowest one - would get to 2.5 and even 2V - most likely dead

i dont plan to get that low - but 22V i think the is highest that can be set- because its set for Lead -

[Burgerman]

Its not as simple as that.
Remember ohms law that you refuse to understand?
Voltage drops under load. So even if an unloaded pack reads 24v it might be 20v or less depending on resistance and current at high load. And on peukert in lead batteries. And on HOW LONG it waits at this low peak before cutting power depends on its programming.

how much can fit in the same physical size shell ?

That depends on internal resistance and C rate capability. Determined by the thickness of the electrodes.

[expresso]

yes i know - under load it can drop alot when its near its end stage -

2.9V can drop who knows what to 2.2V or 2V if going up a steep hill and for some time etc,

was just a ball park figure i am figuring - either way i now know its limits and respect them if i ever use that chair outdoors - i will use it in the summer just to cycle it a bit - staying local not too far - i can do what i used to do when i had Lead - back then that was my longest ride - now its the shortest even with a 6 year old pack i can do the longest ride i used to do with lead and have left over for sure

[Burgerman]

What would you do with a brand new lead chair that 99% of people have? Thats got half the range of your retired chair.

[expresso]

nothing - its useless unless you never leave your house - i would put 200ah in anything new first thing - - batteries and tires -

i wont even rule out completely to doing it even to this retired chair - i want too see how the summer goes - in the very worse case - i can put the ADD on Back on this chair to extend my range without doing nothing else to it

but i rather not - i moved the seat back some - feels fine - but if i add to the rear - would make it too tippy - and i dont like it anymore the ADD ON - on this chair -

its an option if i have no choice - i do it - i would hate to put 200ah in there now and then it sits around - but i guess thats what a back up is for - to be ready and waiting - i wouldnt know what to do with the 105ah i take out after if i did that -

its not garbage really - its has life left -

[Burgerman]

Considering the distance you go and demand, I am very suprised that your motors run as long as they do.

[expresso]

Considering the distance you go and demand, I am very suprised that your motors run as long as they do.

thats another concern of mines and since its not covered - i dont want to use it much - i have changed them out once before - on that chair - and once before on my P222se chair - which i dont use - only indoors and for the dentist or doc. which are blocks away

i have a spare set of motors for that chair - rebuilt - never used them yet - since i adjusted the steer correct in the program settings -

it worked nice - simple fix - i know its not actually fixed - but runs as new as if it was - if i didnt know better - and a tech did that - i would have to just considered that fixed -

i want to use my new chair only now - so if it needs any repairs - or motors down the line - i should be able to get them - i hope since they dont make this model any longer -

i wonder if the new 500H they made - uses the same motor mounting holes etc, its look the same - 8mph rated - and may use the 3 stud hub - instead of 4

but as long as the actual motor is the same - same mounting holes etc, i hope that works - makes me wonder - i should get another set for a spare in a few years -

that would really suck to have two good chairs and cant get motors for them -