PINNED - Lithium battery conversion/info

[Burgerman]

Its easy viewtopic.php?f=2&t=1813&start=620

One simple connector, then sleep. The charger does a perfect job fully controlled and proportionally, with 1A balance circuits. Up to 40A charge. Way better than any crappy BMS. Accuracy to better than 0.003V per cell as I sleep. With you free to choose and save all the voltages charge amps, parameters, etc as you want... Or read off the data, Ah returned, and more from a PC.

The loom is self explanatory. No need for diagram.

I have ONE single connector on my lithium battery pack, fixed to my chair.
I plug the charger cable into that, press GO!

(Or I do it from my laptop, and watch the display, voltages, graphs on screen) One next to my bed.
These two below are next to my PC. Because it as easy to charge there as it does it so fast!


I literally connect this one connector shown here: Press go!

The other half of the cable that is on the chair, looks very similar, (the female half). But just ends in 9 small ring terminals instead, that bolt on to the battery. Once...
Remember that this charger will also work from another chair, or your car (or someone elses) should you need that. This is much better, more accurate, and more reliable, and simpler than a BMS. Read here! http://www.electric-cars-are-for-girls. ... stems.html

[expresso]

Its easy viewtopic.php?f=2&t=1813&start=620

One simple connector, then sleep. The charger does a perfect job fully controlled and proportionally, with 1A balance circuits. Up to 40A charge. Way better than any crappy BMS. Accuracy to better than 0.003V per cell as I sleep. With you free to choose and save all the voltages charge amps, parameters, etc as you want... Or read off the data, Ah returned, and more from a PC.

The loom is self explanatory. No need for diagram.

I have ONE single connector on my lithium battery pack, fixed to my chair.
I plug the charger cable into that, press GO!

(Or I do it from my laptop, and watch the display, voltages, graphs on screen) One next to my bed.
These two below are next to my PC. Because it as easy to charge there as it does it so fast!


I literally connect this one connector shown here: Press go!

810_1084.JPG

The other half of the cable that is on the chair, looks very similar, (the female half). But just ends in 9 small ring terminals instead that bolt on to the battery. Once...
Remember that this charger will also work from another chair, or your car (or someone elses) should you need that. This is much better, more accurate, and more reliable, and simpler than a BMS. Read here! http://www.electric-cars-are-for-girls. ... stems.html

This is what i like - i like this idea - once all done - one cable - plug it in and go - to me thats plug and play once all the work is done of course

[Burgerman]

But what's more, its the simplest way. And better still, its the best way.

It treats the battery well while charging. It does all the stuff the BMS tries to do, but does it properly. And far more effectively and quickly/accurately, with much more precision -- never allowing a cell to exceed say 3.550V (or whatever safe value you choose and with around 10x the balancing power. No cell ever goes over the voltage you set. (A dumb charger and BMS does so repeatedly for hours.) And a good charger does this while throttling the charger proportionally right down to the level of the balancer, or less, to 10mA if needed. And smoothly. A BMS systems cannot ever do this properly because they can only wait till a cell goes "high" then cut the charger off completely as they have no control over it, and then try and drag the high cells down while we wait. Over and over. With tiny 100mA balance circuit (10x less typically than a hobby charger).

And then they do all the other stuff we don't require, and actually really do not want, as well + theres no need to have one, or all its connections and wires and components on board, waiting to fail and cause a fire...

Did you read this:
They see this exactly as I do. http://www.electric-cars-are-for-girls. ... stems.html

[expresso]

Your Right - i have a much better understanding now - its too bad - so many problems with doing it right with a BMS - less is always better -

your getting me worried about this Fire hazard thing now - do i need to get this to wrap it ? http://www.amazon.com/dp/B00XBG0GOK/ref ... E36O2SVE2M

If i do the whole chair - it will be with No BMS - i am going to start to work on the balance wiring also once i finish the ADD On for now - i will give the BMS a try - from shirley - if hes been using it for years and it works for him - i will continue as planned with the ADD on this way -

but looking past this ADD ON - the whole chair project when i get there - is going to be NO BMS - i dont want to worry about it once its done - i dont want to open my battery box all the time if anything should go wrong etc, -

thats the plan - and i am starting to feel much better about the whole thing - with the charging - one good cable mounted to the chair - which charges and balances -

the hard part is just getting it all done - correctly - and attaching the balance cables where they belong - etc, - but once thats done - should be smooth sailing after that -

hows this item for when i need to make the balance cables - would this do the job easily - cuts and pulls it apart - i like that -

http://www.amazon.com/dp/B01018CYV8/ref ... WK0H5RPW9F or would this be better ?

http://www.amazon.com/dp/B000OQ21CA/ref ... 7USCTVWGSH

[expresso]

i also got this in the mail today - http://www.amazon.com/gp/product/B003DF ... ge_o05_s00

http://www.amazon.com/gp/product/B001JY ... ge_o05_s00

when i make the leads - was going to use this fuse holder and fuse - but not sure now - its much larger than i expected - the fuse holder -

the fuse is also very large compared to my other 30amp fuses - seems built well - the wire i guess i have to cut in the half and then attach with a butt connector ?

i am not sure if thats the correct way - just a butt connector and not solder ?

what do you think BM - ? what would you suggest ? do you know of a smaller fuse holder maybe ?

i wonder why it comes closed loop wire ? why not have it cut already in half - i guess its better for me since i may not use this for some time -

i am slowly building all the tools i need - my cart is getting full already -

what do you think about this fuse holder and fuse ?

[Burgerman]

Mines just soldered into the cable and heat shrink over the top.

[flagman1776]

I guess making the fuse holder in a closed loop allows more flexibility in positioning but I know what you are saying. Looks the same as the ones I used. I installed one in my charging lead. I used the metal tube from a crimp connector (after removing the plastic insulation)... butted the fuse holder to my charge lead and soldered. Then covered the splice with heat shrink tubing. If you can't get the shrink tube on after, sometimes you must put it on in advance & push it well out of the way.
It's also possible to strip the wires to be connected... takes more wire length... twist them tightly together from opposite directions & solder. I use my electrical forcepts to help hold the wires while doing this. And the use heat shrink tubing over your splice. (This technique is more troublesome & more apt to conduct enough heat to spoil the shrink tubing you carefully slip out of the way.)

[Burgerman]

40A fuses soldered. One on each cable. Clear heatshrink (so you can slide back nylon sleeving and take a look at the fuses if needed).
Fits easily inside my charge cable sleeving (shown above) since its expandable, along with 9 thin balance wires.

Not easy to swap without a soldering iron. But then they shouldn't fail ever unless you do something silly. They are in here download/file.php?id=4179&mode=view

[expresso]

I see - i guess i will practice and see how it works out - I though 40A fuses is not enough ? i read in other posts to use 60 A to be safe - if you use 40 A - how do you charge at 40A - wouldnt that blow a fuse ?

i dont see any other way to use that fuse holder other than to cut the wire in the middle - strip it - both ends - wrap together to lead wire - if i use a butt connector - can i just crimp it down - and heat shrink over it or do i need to solder with butt connector - or just solder and heat skrink over that ?

i want to make sure once i do it - i wont have to do it over - the fuse i got - is at least double the size of that 40a fuse in the picture - i wasnt expecting it to be that large - -

i see you fuse both wires - Pos and Neg - any reason for that - i though only the Pos . wire needed a fuse - whats the Pros and Cons of doing both wires ?

[expresso]

I guess making the fuse holder in a closed loop allows more flexibility in positioning but I know what you are saying. Looks the same as the ones I used. I installed one in my charging lead. I used the metal tube from a crimp connector (after removing the plastic insulation)... butted the fuse holder to my charge lead and soldered. Then covered the splice with heat shrink tubing. If you can't get the shrink tube on after, sometimes you must put it on in advance & push it well out of the way.
It's also possible to strip the wires to be connected... takes more wire length... twist them tightly together from opposite directions & solder. I use my electrical forcepts to help hold the wires while doing this. And the use heat shrink tubing over your splice. (This technique is more troublesome & more apt to conduct enough heat to spoil the shrink tubing you carefully slip out of the way.)

i guess the way you did it might be best or easiest - did you use a 8 AWG butt connector ? how was the fit - you crimped it down first and then soldered it - or just soldered -

if theres a better fuse holder etc, - any one know of - let me know - i wont be doing this for a while so can always change fuse holder - and keep this as a spare or something - its a heavy duty fuse holder - just very hard to remove the fuse if you ever need to -

[Burgerman]

My systems are a bit more complex. 2 chargers, 45V. One 6S battery, one 7S battery, 2 isolated chargers, two isolated power supplies... There are so many possible ways to short something that I thought it better to be safe! In your case 1 fuse will be OK.

Mine isn't for driving a chair. Its for charging. A 40A fuse and a 40A charger is fine. It will take 60 or 80 amps to blow it. If you short out a battery you may get 1000A plus. Hence the need for a fuse at all. It protects charger, chair but mostly the cables.

You size the fuse to protect the wiring.

[flagman1776]

I guess making the fuse holder in a closed loop allows more flexibility in positioning but I know what you are saying. Looks the same as the ones I used. I installed one in my charging lead. I used the metal tube from a crimp connector (after removing the plastic insulation)... butted the fuse holder to my charge lead and soldered. Then covered the splice with heat shrink tubing. If you can't get the shrink tube on after, sometimes you must put it on in advance & push it well out of the way.
It's also possible to strip the wires to be connected... takes more wire length... twist them tightly together from opposite directions & solder. I use my electrical forcepts to help hold the wires while doing this. And the use heat shrink tubing over your splice. (This technique is more troublesome & more apt to conduct enough heat to spoil the shrink tubing you carefully slip out of the way.)

i guess the way you did it might be best or easiest - did you use a 8 AWG butt connector ? how was the fit - you crimped it down first and then soldered it - or just soldered -

if theres a better fuse holder etc, - any one know of - let me know - i wont be doing this for a while so can always change fuse holder - and keep this as a spare or something - its a heavy duty fuse holder - just very hard to remove the fuse if you ever need to -

To use the crimp connector, yes, crimp both sides into the tube, then solder. Nothing moves that way & corrosion is not an issue. Just be sure how you are going to get the shrink tubing over it (one end free). Or slid the shrink tubing well away from the joint until the solder is cool enough to handle.
I didn't have uninsilated butt connectors on hand... I used a punch block & slightly smaller punch to push the connector out of the insulation.

[Burgerman]

To join 2 wires, better not to. Remove original and fit one longer bit.

But if you must, just cut them square, strip only as much as the cable diameter. Flux one end. Push the strands into one another. Heat, solder. Slide heat shrink over the top.

https://www.youtube.com/watch?v=7t9nT3Hn9b0 watch!!! Then heat shrink. The hobbyists get it.

https://www.youtube.com/watch?v=Q9G9gaokqvM CLEAR PICS. Well described and done. Other than he strips far too much cable.

Mistakes! https://www.youtube.com/watch?v=igqkhkff6cw

[expresso]

video dosnt seem too bad - i think i can manage to solder them - or maybe both butt connector and solder - heat shrink over it - to replace the whole thing would be harder for me i think - i dont even how it can be removed from the fuse holder -

i am sure to damage it and render it useless - when time comes i will give it a shot and see how it work outs - i will practice a bit first with the soldering on other wires to get the feel for it -

[Burgerman]

Why use a fuse holder. I didn't.

[expresso]

i though thats how its done correctly - in case you have to change the fuse - or something - on my other chair - i changed the fuse already - because it was 20 A fuse - and my charger was 20 A - i though that would have blown the fuse being so close in Amps - i put 25 A fuses in both chairs for that reason - not knowing it was OK with either fuse

in the event i do have to change the fuse - it would be ALOT easier for me to change it - with fuse holder than having to unsolder - and remove the cable from the pack etc, etc, - then to just remove fuse from holder -

i know what you mean - i never blown a fuse since it was added - a few years now - so it should never blow anyway - so the Odds are low - that it would happen - but if it did -

i rather take the time doing the fuse holder correctly if i can - and not worry later -

[LROBBINS]

Fuses are rated by the current they will carry indefinitely without opening. So, a 40 Amp fuse will carry 40 Amps forever. At 80 Amps it will take several seconds (at least) to blow. I just took a look at Littlefuse data sheet for maxi blade fuses - at 100% of rating they won't blow for at least 360,000 seconds (100 hours), at 200% of rating it will open in between 2 and 60 seconds. There are also faster acting blade fuses available, but not as common. Ciao, Lenny

[expresso]

Fuses are rated by the current they will carry indefinitely without opening. So, a 40 Amp fuse will carry 40 Amps forever. At 80 Amps it will take several seconds (at least) to blow. I just took a look at Littlefuse data sheet for maxi blade fuses - at 100% of rating they won't blow for at least 360,000 seconds (100 hours), at 200% of rating it will open in between 2 and 60 seconds. There are also faster acting blade fuses available, but not as common. Ciao, Lenny

i see - so really i could have just used a 40A on the cable that i would charge with - and be just fine - i got the the 60 A fuse already so i would just use that now - if i choose to use other fuses in the holder - it should be fine also ?

http://www.amazon.com/gp/product/B003DF ... ge_o06_s00

as long as its a Maxi fuse - i can use what ever Amp - but not over 60A ?

[Burgerman]

The fuse is to protect thee cables, because the battery can put out hundreds of amps if something is shorted or wrong. So as long as the fuse is weaker than the cables, and bigger than any current in service it will be fine.

[Scollard]

i see - so really i could have just used a 40A on the cable that i would charge with - and be just fine - i got the the 60 A fuse already so i would just use that now - if i choose to use other fuses in the holder - it should be fine also ?

http://www.amazon.com/gp/product/B003DF ... ge_o06_s00

as long as its a Maxi fuse - i can use what ever Amp - but not over 60A ?

I used a 100 amp AGU fuse and holder for my charge cables. No soldering, no heat shrink, easy to replace, it also provides a breakpoint for me because I mounted my connector on the battery box cover so to remove it I break my connection at the fuse holder. They are easily found on Amazon and are pretty inexpensive.

[expresso]

thanks - i have to search that fuse holder etc, - that sounds good to me -

http://www.amazon.com/IMC-Audio-Inline- ... 5Q9Q9ZDF36

http://www.amazon.com/gp/product/B007WX ... _mrai_3_dp

with this - i just have to stick the bare wire end in and screw it down - ? is that very secure ? i would think if its yaked or pulled wrong by mistake - it would come loose ?


like making audio cables with a banana end screw down ?

[Scollard]

thanks - i have to search that fuse holder etc, - that sounds good to me -

http://www.amazon.com/IMC-Audio-Inline- ... 5Q9Q9ZDF36

http://www.amazon.com/gp/product/B007WX ... _mrai_3_dp

with this - i just have to stick the bare wire end in and screw it down - ? is that very secure ? i would think if its yaked or pulled wrong by mistake - it would come loose ?


like making audio cables with a banana end screw down ?

Yep, just screw it down. No it will not pull apart.

[expresso]

that i like - thanks -

i seen those before but i figured it was for Car audio - and maybe not the same etc, - if i knew - i think i will order a few of those - with a 60A fuse to be on the safe side of things -

this would be much better to make and not too huge -

[expresso]

How long have you been using that type of fuse holder etc,

have you ever blown a fuse ?

[Scollard]

How long have you been using that type of fuse holder etc,

have you ever blown a fuse ?

Only once when I accidentally shorted the system putting it all together. It blew immediately. Never while in use normally.

I will use the same setup with my LiFePO4 pack except I will only have 1 combo Sub-D connector. My current lead system is exactly like BM's setup with 2 Anderson connectors, either hooked up in series for running or parallel for charging from my SUV, or charging in series from my Hyperion at 24V.

[Burgerman]

You can of course still charge with a hobby charger - actually faster at a high continuous rate till nearly full - as you drive. But with a lithium systems range and not hurt much by depth of discharge because its bigger Ah, it all becomes unneccasary unless you are not connected to the grid somewhere.

Of course it works the other way around too. You can charge your van from your chair at 40A with the PL8 should you get stranded with a flat battery somewhere. So worth keeping a charger in the van. 10 mins boost and you are good to go.

[expresso]

How long have you been using that type of fuse holder etc,

have you ever blown a fuse ?

Only once when I accidentally shorted the system putting it all together. It blew immediately. Never while in use normally.

I will use the same setup with my LiFePO4 pack except I will only have 1 combo Sub-D connector. My current lead system is exactly like BM's setup with 2 Anderson connectors, either hooked up in series for running or parallel for charging from my SUV, or charging in series from my Hyperion at 24V.

Ok - i was reading some reviews - and one guy had blown 5 fuses in a few months - was wondering if its the fuse issue or some other issue he may have had - this was on a Car audio system -

got me concerned - not looking to change fuses - if thats the case - i may just stick to the one i have - but i like this kind because its easier for me - may he had cheap fuses -

which fuse would you recommend ? brand and size etc, -

[Burgerman]

Ok - i was reading some reviews - and one guy had blown 5 fuses in a few months - was wondering if its the fuse issue or some other issue he may have had - this was on a Car audio system -

Hes a retard.

[expresso]

[ex-Gooserider]

Basic idea is that the fuse holder is not essential - it just makes it easier to change the fuse if it blows - but if you don't do things to short it out, and size the fuse right it shouldn't be necessary to ever change it...

Only time you could make a case for actually NEEDING a fuse holder is with small fuses that can't take the heat of soldering.

Also note that you do need to work fast when soldering directly to a fuse, as the fusible element in the fuse is heat sensitive, and you need to avoid getting it hot enough to be damaged during the soldering - not a big deal, just takes a good setup and practice...

ex-Gooserider