Burgerman wrote:Timm should read this thread.
He still seems to think its all impossible for him. Thinks powerchairs run on some kind of "new" marketing magic!
Your virgin mum did a marvelous neat job. The underside of those cells have electrical insulation too right?
steves1977uk wrote:Nice build FJ! Anybody can do this if they're willing to learn and take time understanding everything. Nothing is impossible. Those sticking with Lead bricks are going to be left behind.
Steve
expresso wrote:very nice -great job - will be great inside the bounder box - i was almost going down this road till i got the lithium covered with the bounder -
too bad only 100ah inside - not enough - 200ah will be great inside and if you need more range - 100ah outside you have 300ah bounder
first of its kind - i did 68 miles on my bounder just once to see - using a 180ah total pack - i never done that much since -
you will have fun this summer
Burgerman wrote:Thats what I keep telling everyone.
Burgerman wrote:But now you have real freedom with no range anxiety. You realistically have 5x the range. And thats going to take a while to get used to.
Why 5x the range? Because realistically your chairs old lead bricks run out and you stop after around 12 miles. So set off, drive full speed along the footpath for 2 hours at 6mph. Thats it. 6 mph for 2 hours is 12 miles... Maybe a fraction more if you slow down a few times to rest the batteries. At this point your red light is on or will be very soon, and if you recharge the battery you see that only 35 to 40Ah is returned. This is because of peukert. At this 2 hour rate thats all the lead can give you.
But now you have 5x this 40Ah available. So you can go at max speed, for 10 hours solid without a break! If you have the backside for it... Because theres no peukert decrease on lithium.
You are used to looking to see if you "lost a light" or two and turn home. Or you dont attempt to go out in the evening into town because you aleady had a busy day. It takes a long while to lose this feeling. Its subconsous. It limits what you attempt. And you dont know you are doing it.
Forgot to charge last night? Had planned to go to a big day out like an airshow? No problem... And then go out again to another town in the evening. Incidentally how old are you? Are pubs / clubs and loose women your thing? I am getting older. I seldom need that much range. But its nice to never have to think about it.
AgGuy wrote:I appreciate all your posts on this build.
When switching to lithium, is any controller programming required to make it work properly?
im still trying to wrap my head around all the range
Burgerman wrote:What connector now?
The one I used?im still trying to wrap my head around all the range
Its better than you think. Because the fear of running out of juice means you always tend to get back home with a fair bit still remaining. Its a subconsious thing. It garantees you never get caught out. But it means you only really use about half to 2/3rds of that lead bricks 40Ah usable power. So that 5x 40Ah is really 6.6x 30Ah... So you will go for what feels like 5x further, and still have about the same as a set of lead bricks could give you remaining. And a half...
Just be sure to never let any cell go below 3V ever and you wont go far wrong.
Burgerman wrote:When they do it will be with a limited capacity bms controlled lead brick replacement. Or a pack again limited in capacity, like the BMS controlled bounder pack.
All of which entirely misses the point! Which is to say they will throw away the main advantages that this chemistry offers. Such as huge 500% range gains, fast charge capability, battery extended service life due in part to no BMS issues and low loading on a huge pack. But they dont care, think of the marketing bullshit!
Permobil are already well into that with some common lead bricks. Labled as "special" permobil branded ones.. Which they are not (special I mean!). And a "matched" special permobil charger (again its a generic 10A AGM/Gel one size fits all so nothing special at all). But they already have Timm convinced that its something new/special!
I
Many manufacturers like sunrise already INSIST on 10A chargers with heavy or faster chairs. Because otherwise battery issues and warranty problems arise... However 10A is only a fraction better than the usual 8A. What is really needed is an aprox 25A charger. According to most battery manufacturers. So that the bulk of the charge gets put back fast. Meaning theres almost long enough overnight to get a long enough CV stage. But if they can turn this into some "new" "modern" marketing bullshit then they will...
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