60ah ADD ON build with Pictures

[expresso]

yep

[expresso]

Ok all done full discharge

the graphs show much better now - Cell 3 is just the weaker one and dont think that will change - i am not going to touch it anymore and will recharge it now and attach it to the chair tomorrow

looks like the End volt is 24.3V - yesterday it was 24.1V - not much difference - - not sure what i can get out of this pack in use - i hope to find out this week -

do you think i can pull of 28 to 30 miles ?

would this be considered a true 50ah usable at least ?

[Burgerman]

You got almost 55.4 Ah out that time. So 10Ah better.
I told you that it may improve a little with a few cycles. They may have been stored a while, and a few cycles of exersize restores them.

So you can safely take 50Ah and leave 5Ah in reserve. Had you taken them to 2.5V you would have seen another 3Ah ? So now they are 58.4Ah... Keep the figures so you can retest in a year.

So yes as long as your lead is still healthy, you will at least double its range. Normally you will get 40Ah to 45Ah from a good set of GRP 24 batts in use. And return around 50 to 55Ah to them.

Dont ever go lower than 24V. (Better at 24.4V really). So there will be some lead left over.
Thats what the simple silicone diode is for. Then you could go .65V to .70V lower.
So you could keep going safely to 23.3V which means your battery meter will work, and the lithium is safe and you use more lead so btter range. And all the regenerated power goes to the lead.

[expresso]

the charging graph shows about the same curve as before - more or less - maybe a touch better - still going - the lead in this chair where new to the best of my knowledge - and were never used with out a ADD ON pack -

based on the 30ah add on - i used about 30 or 35ah of the lead before its done - i base this on the Cap in when i recharge - getting 60ah Cap back in when down to 3V on the ADD ON - so i figure i used 95% of the ADD ON and the rest was lead -

i hope to get this a try out tomorrow - i want to push it to find my max range - but may do it slowly after a few trips - so i have an idea how far i can go before turning back -

simple silicone diode-- sounds simple enough but then last i remember - it was a large item i have to solder in line on the lead battery ? needed Air etc, to breath - sounds more involved than it seems to me

that way i may get an extra 10ah of lead out of it - or 15ah at most - but means i am going down to about 80 DOD on the lead - so they wont last as long - ?

i want to preserve the lead this time around - i wont be getting any more new Lead for this chair or any other chair now - since they are off service soon meaning insurance wont cover them once i get my new chair in sept. -

if i have to buy my own Lead - i rather just make a 90ah lithium pack for that chair - and be done with it - but i want to make the lead last as long as i can with this half ass 60ah ADD ON - -

[Burgerman]

Diode goes in the cable between addon and lead.

[shirley_hkg]

Diode goes in the cable between addon and lead.

On second thought , his lead bricks will receive 0.65V lower too during recharge that seems undesirable .

[expresso]

Diode goes in the cable between addon and lead.

i guess its good to know how to add it - if someone is doing this and wants to get the most out of the whole pack - i am not going to do it - this will most likely be the last Lead chair i will use - after this lead dies out - unless i get it for free - i would just use it as is - in a few years this chair will most likely end up being my indoor chair by then - in that case - even if i just used this 60ah pack to power the whole chair - would be just as good as having Lead alone -

who knows things change fast with these chairs - so far my indoor chair is close to 15 years old - and i have no plans on getting rid of it as long as it works for me - but at some point - it may have to be replaced and this combo lead add on will be the replacement if it holds up -

or if i get the itch - when lead is dead - replace it with lithium also - i keep going back and forth with that idea - not sure its worth it if its only used indoors - thats better even if i stick this 60ah inside the chair - would still work me indoors

[Burgerman]

Is it?

28.80V is 3.6V per cell. OK for the addon.
Diode reduces that to the perfect 28.15 for MK in summer...

Set charge 8S, 3.600V with 500thC or 4 hour max termination. So set to 70Ah+60Ah = 260mA.

[expresso]

maybe you can do a short section with pictures on how to add one to the line and where to add it etc, - step by step type of instructions would be great

maybe others who are using or going to use an ADD ON with lead may like that idea - the whole point though was to have the lithium do most of the work so the lead can last many many years - i though that was great - not have to worry about changing out the lead every year etc, -

how much do you really lose from the lead you dont get to use approx. ? 15ah of lead unused maybe - better off leaving it alone and have them last - you wont get much more range i wouldnt think anyway -

[Burgerman]

Then you can use a lower voltage drop shottky diode. Instead. Lose .3 of a volt. Then you use a bit more lead, but battery meter will make more sense, and range increases some. Lithium safer at the end of a trip.

2 small ring terminals, in the positive wire to the chair. https://uk.rs-online.com/web/p/rectifie ... s/8184553/ And a bit of heatshrink. This will probably be fine without a heatsink as it will just warm up the wires. Its designed to be OK up to 175C so no worries. Its low drop at high current. And about .3v at zero/low currents.

[expresso]

would have been good from the start - i am done with working on it now - i need to start using this tomorrow - this is my only chair now -

looking at my pack - i really cant redo the wiring just to add this thing - but maybe if i feel up to trying it - i can make a xt90 connector with this in the middle and add it between the line going to the ADD On Cable to the chair

now i had a cable made already first one - with both SB50 ends - my pack i made it with a xt90 end - so i made an xt90 to SB50 short adapter already - not to remake the whole cable -

i would have to add this between also then - would be easy to add once made -

i would buy that item - ring terminals on Pos. wire - heat shrink it - and make xt90 end to connect -

is that the best one to get in terms of size etc, -

is this correct how i am thinking of doing it ?

[expresso]

do you have a link to what i need to get from the US ? searching that only shows up from UK - even on ebay -

[Burgerman]

Any 50 to 100A schottky diode.

https://www.ebay.com/itm/Vishay-VS-100B ... m570.l1313

Free shipping from UK?

[expresso]

Any 50 to 100A schottky diode.

https://www.ebay.com/itm/Vishay-VS-100B ... m570.l1313

Free shipping from UK?

ok i put it in my cart - do you know what size bolt screw nut i would need or should i wait to get it and then bring it to hardware store ?

or i can solder it ? tin the wire end and solder it - that will go on the Pos. like an inline fuse would ?

[expresso]

Ok all done - this is most likely the best it will ever be -

will cover the pack - tape it a bit - stick in my bag and connect it for the first ride tomorrow - if it dosnt rain hopefully -

will bring volt meter with me and check it - 24.5V is safe - tricky part is i need to be home once it reads that - i will try to do 26 miles - total

13 miles one way and return just to be safe - then i can see on the recharge if i had more left safely - slowly inch my way up to 30 miles if its doable

[expresso]

this pack gives me more AH than my chair did before with lead and 30ah ADD ON combined - so it has to give me a decent amount of extra range


i think 80ah to 85ah when its combined with the lead before its done -

[Burgerman]

That addon alone is basically about 10 or 14Ah better than a set of grp24 batteries.

If it was me, I might order 1 cell. And just fit that in position 3.

[expresso]

That addon alone is basically about 10 or 14Ah better than a set of grp24 batteries.

If it was me, I might order 1 cell. And just fit that in position 3.

too much work now - i need this to use on my only chair i have outdoor use right now - its all done and will be using it today first time -

cant trust buying another one anyway - may get one the same or worse who knows - would be a long winter project if i wanted to take that thing apart to replace one cell - with no guarantee it will even work out -

i have 8 more headways on the way - will add those to the 30ah this replaced to have 45ah with headways which i know are brand new high C cells for sure

first ride today with it - - we see

[expresso]

by the way - this charge cable i made this time - was best i done - came out perfect -

the trick is - do it in two days - first day - prep everything - tin wires - cut to size - get every ready in order -

next day - - do it - i work better on my computer desk to solder this - than i do on my kitchen table where i do other stuff - so now i know

[Burgerman]

Big ball of blutac is my saviour! Its the same as many hands!

[expresso]

Ok first Run - i ran it down to the end - not too bad - got me thinking now about replacing Cell 3 - in the winter of course - this just saved my summer

i can deal with 30 miles on one charge - thats what i got today - Cell 3 lowest at 3.0xx volts - the rest where 3.1xxx volts - total pack volt 24.83 V - not too bad -

too bad i got that one weak Cell - - next ADD ON i may go for the 75ah Cells - i was debating them - and decided on these for a few reasons - one being they where shorter height - but the 75ah Cells were thinner and would have fitted in my box with out having to extend it cut it etc, - just the top wouldnt lock close - i would have - or could have dealt with that - could have worked - all well -

this was intended to be a winter project - till my Main chair motors are dead - so i was rushing to get something fast - and went with these -
but its amazing how much better the range is now -

i now feel at least do 60ah ADD ON - or 45ah ADD ON if using Headways - - i wouldnt do anything less -

[Burgerman]

Your lead batteries are still about 1/3rd or more full. So a diode would let you go another 5 miles. But 30 real world miles rather than the 20 ISO test bullshit miles is still pretty good.

[expresso]

thats pretty good - but its ok with the lead - this way i wont work them hard and they last since i wont be getting new ones for this chair - this way - this can last many many years - and i wont have to worry about them - replacing lead in this chair means it has to come apart - top off the base etc, - its a bit of a pain but mostly not looking to pay for lead ever again this 60ah pack - cost about the same -

so if you compare them - lead would be dead in a year or so - easy - 60ah pack would keep going for many many more years - cost the same - so isnt worth paying for lead - if i got them free - i change them out - but i wont anymore -

i feel much better now - Cell 3 - what can i do - - not too bad if you think about it if it stays this way - once i get my main chairs back in working order
this one wont get used hard and will sit as my back up back up chair

[expresso]

Your lead batteries are still about 1/3rd or more full. So a diode would let you go another 5 miles. But 30 real world miles rather than the 20 ISO test bullshit miles is still pretty good.

if i did add that - and get 5 more miles - it would drain the lead deeper each time - but also what if it fails - then the ADD On wouldnt work - ?

lets say i am 15 miles away when it fails - i have to get back on lead which wont make it from that distance -

like the first time when i had a 30A fuse on the ADD ON line - one day it did blow - i noticed it right away on my JS - lights were going out way too early and i knew something was wrong - fuse was blown and i was on lead alone - i wasnt too far then and was fine getting back

remove it and left it - all good since

[expresso]

i reached the point where if i had to use a Chair with just lead in it - wont be worth it to me to even get up dressed etc, all that work to go out with lead chair and not go far anymore - 2 hours or 3 at most and have to be home - i wouldnt even bother going out -

thats how i got so accustomed to lithium now that at the very least - have to use an ADD ON - and now at least 60ah ADD ON - if not more 75ah is more like it -

for my next one i will consider 75ah cells - if i can find new ones - a bit wary now - after this purchase - - i would have to take more time in deciding which i didnt have time now if i wanted to savage my summer

[Burgerman]

if i did add that - and get 5 more miles - it would drain the lead deeper each time - but also what if it fails - then the ADD On wouldnt work - ?

lets say i am 15 miles away when it fails - i have to get back on lead which wont make it from that distance -

Not sure what you mean by fail. At the moment as you drive, you use lithium for the first 1/3rd the trip. Then lead AND lithium for the next 1/3rd, and then you are home. Down to your 3V. Leaving much of the lead (the last 1/3rd) unused.

If you fit a diode, then as you set off, you will use both, together, (but still more lithium, in a more matched way. So at the half way point you will have used about the same of each. So you will have less lead, but more lithium left to get home than before.

[expresso]

i mean if that thing i add in the line to even out the discharge - - can that fail like a fuse ? if that failed - then the lithium would stop there - and only running on lead from that point on -

[Burgerman]

Anything is possible. Your whole chair depends on mosfets,diodes, resistors, etc. If it fails, you could just remove it and join the wires.

[expresso]

its a good idea - Can i just solder that item to the wire if i did it and heat shrink over it ?

i may not do it or i may make another adapter with one in line and just swap it out - - chair is still charging up - looks like it may end with about 80ah Cap In when done

if the 60ah pack is really giving me about 50ah of use at least and the gel is about 30ah make it about right at 80ah - if this pack gave me the full 60ah - then i would have a 90ah pack

before i was getting about 60ah cap in - with the 30ah headways - so i figure the lead is giving me 30ah of them - if i added the thing in line - i can get another 10ah to 15ah out of the lead -

90ah to 95ah pack but lead would get discharged alot deeper all the time -

i am thinking about what you said - about replacing Cell 3 only - its an idea -

[expresso]

First Full Trip with 60ah ADD ON - getting 50ah at least out of it -

this is the recharge - and when i got home - monitor before i recharged - at 30 miles - the weakest Cell 3 - 3V -

So there you have it - anyone can do this - just have to be careful finding the right Cell - trying to find good new cells is hard the way i did it - so be prepared for NOS Cell and even used but sold as new - who knows - its the wild west in China anything goes

i would shoot for 75ah Cells for ADD ON if it can fit - then you may get lucky or if not maybe a good 60ah to 65ah out of it instead -