The battery is built.... Now for
- Thread starter Low
- Start date
I have the 10S version and N does nothing and has no effect on the performance.
I've built a 10S4P prototype pack with Samsung 25R and if I'm happy with that, I'll build a 10S5P which should give 17ah although I'm hoping that by the time the battery is due to be replaced on my Neo Cross, there might be something more powerful than 3.5ah 18650s available! Seriously, what is stopping me is choosing a BMS; I've tried 3 and the type you've got seems the best. None of them are particularly good if the pack is unbalanced itself, i.e. where dissimilar capacities are used. They charge just about ok but when the pack is discharged, this results in premature disconnection through a cell going below 3v whilst the others are >3.1 Potentially, I could lose 10% or more of the available capacity. Bit harsh blaming the BMS perhaps.
The other BMS I tried all seemed to have an inability to re-connect once the cells achieved recovery voltages. So, if you left it charging, the BMS wouldn't continue charging once the cell voltages all were below 4.15 volts which is its recovery voltage.
Seems I've bought the same welder! Great to see what you've done. I'm doing the same except I'm using the 2S nickel strip. I expect never to be able to recell the Neo Cross battery because it's banana shape is difficult to hold together so I'm doing what you've done and put it on a rack. I reckon I only need to lose 2.5kgs in weight for the additional weight to be "unnoticed" and the new slimline shape of the rider will be more streamlined erm .....
I'm buying my cells, new, from NKON, at 3 euros apiece, and they're nothing like as economic as yours but I was seriously concerned at risking a mismatch. This Chinese stuff is ok so long as the input is perfect, if you see what I mean!
Bike all done apart from some water proofing on the battery bag, although the bag is a motorcycle tank bag and is is prob near enough water proof anyway, i ran the cables out of it in black then down the centre stem into the controler via an xt90 connector, was quite pleased that the xt90 would just about take a white 18650 shrinkwrap around it so after i soldered it all up i was able to use up some leftover white 18650 shrink wraps to colour it with the frame, then had the bike upside down and glue gunned everything that looked like a water risk and have obsessivly shrink wrapped everything else, if you are wondering why i haven't tightened the cable ties where the power cables run, this was deliberate, although it would have looked neater with them taught as they are i can remove the battery from the bike without needing to cut them off each time.
every-time i take her to work i put a tick next to £10 on my fridge chart very satisfying indeed!!
Because i went cheap on the 18650s and despite trying to tally each set up i still cant quite get to 56.4 fully charged, iv defo lost some efficiency somewhere but hey, the damn thing is performing great, probobly can afford to only hit 53.9volts if ya rocking 143cells and What i have noticed is how puncy it remainsafter a mike or two, the bottle battery eases up after a mile or so, this one really has legs, going to take both batteries and do a sensible 20mph distance test see if its viable to take to some of my further places of work, start ticking 20s on the fridge
Down sides.. Obvious weight and size of the rear mounted suitcase, although tbf it looks bigger in the pictures! Also continious pluging in and upplugging of the original battery is a worry, it has a cheap looking 2pin male/female setup and looks like it wont last... If i could of got the build up to 54.6 id of happliy left them both plugged in and only seperated to charge.. Oh and i didnt even need to buy a seperate charger just spliced my old one, see pics to follow
every-time i take her to work i put a tick next to £10 on my fridge chart very satisfying indeed!!
Because i went cheap on the 18650s and despite trying to tally each set up i still cant quite get to 56.4 fully charged, iv defo lost some efficiency somewhere but hey, the damn thing is performing great, probobly can afford to only hit 53.9volts if ya rocking 143cells and What i have noticed is how puncy it remainsafter a mike or two, the bottle battery eases up after a mile or so, this one really has legs, going to take both batteries and do a sensible 20mph distance test see if its viable to take to some of my further places of work, start ticking 20s on the fridge
Down sides.. Obvious weight and size of the rear mounted suitcase, although tbf it looks bigger in the pictures! Also continious pluging in and upplugging of the original battery is a worry, it has a cheap looking 2pin male/female setup and looks like it wont last... If i could of got the build up to 54.6 id of happliy left them both plugged in and only seperated to charge.. Oh and i didnt even need to buy a seperate charger just spliced my old one, see pics to follow
I would be tempted to get a BC168 charger and charge 6 seperate series at a time up to 4.2v through the balance lead just once or twice, then you know it's been properly balanced. I've done this in the past with my old bottle style battery and that helped me with a capacity issue at the time.
http://www.ebay.co.uk/itm/BC168-RC-Model-Super-Speed-Li-ion-Li-Polymer-Li-Fe-Hobby-Balance-Charger-BC016-/252166105413?hash=item3ab6456945:g:6isAAOSwDNdVyZbt
http://www.ebay.co.uk/itm/BC168-RC-Model-Super-Speed-Li-ion-Li-Polymer-Li-Fe-Hobby-Balance-Charger-BC016-/252166105413?hash=item3ab6456945:g:6isAAOSwDNdVyZbt
I have the 10S version and N does nothing and has no effect on the performance.....
Wish u were here last week that -n was mega confusing me!!
Seriously, what is stopping me is choosing a BMS; I've tried 3 and the type you've got seems the best....
Yep im quite happy with it, packs seems to be getting healthy each charge/discharge, so far so good
Seems I've bought the same welder! .......
Struggled with mine to get it set perfect, bought some longer heads in the end and bent them, can literally reach 4/5 cells in now.
I'm buying my cells, new, from NKON, at 3 euros apiece...
Very reasonable, my next build is to be the same size but with better cells, found a new laptop battery on ebay states 5200 Mah (6cell) its £6.99 about 8 euros (?) have ordered one to test, if good il go bulk on the guy
Wish u were here last week that -n was mega confusing me!!
Seriously, what is stopping me is choosing a BMS; I've tried 3 and the type you've got seems the best....
Yep im quite happy with it, packs seems to be getting healthy each charge/discharge, so far so good
Seems I've bought the same welder! .......
Struggled with mine to get it set perfect, bought some longer heads in the end and bent them, can literally reach 4/5 cells in now.
I'm buying my cells, new, from NKON, at 3 euros apiece...
Very reasonable, my next build is to be the same size but with better cells, found a new laptop battery on ebay states 5200 Mah (6cell) its £6.99 about 8 euros (?) have ordered one to test, if good il go bulk on the guy
Defo would be nice to know and nice to get them level, just out lay expence on things really.. Il defo look into that tho
Thanks
https://www.ebay.co.uk/itm/252699717619
can anyone buy cells with 2000mah plus brand new cheaper than this?
can anyone buy cells with 2000mah plus brand new cheaper than this?
That's 3S2P? So the batteries in it are each 2,600 mah and they're new and it's in a packaged Dell power supply and its delivered free from Hong Kong. That's too good to be true? Have you a capacity tester? There are reasonable 60watt electronic load testers with all the frillls.
Last edited:
D
Deleted member 4366
Guest
The battery is too high and too far back. You need to modify your rack or get a new one. it should be mounted more like this ine, which is a 27Ah 36v LiFePO4 one at about 9 kg.
In your BMS, there's two banks of switching mosfets. I'm pretty sure that one bank switches on when charging conditions are met and the other when discharging ones are met. N- would therefore be live with battery voltage when either condition is met ("OR" logic). For P- to be switched on to B-, both conditions must be met ("AND" logic).
If none of those pads were marked, I would have said B- in the middle, C- on the bottom one and P- on the top one with the shunt. Then, the charging and discharging controls would work independently, but the BMS would only be able to handle half the power because there would only be 4 mosfets for discharging.
In your BMS, there's two banks of switching mosfets. I'm pretty sure that one bank switches on when charging conditions are met and the other when discharging ones are met. N- would therefore be live with battery voltage when either condition is met ("OR" logic). For P- to be switched on to B-, both conditions must be met ("AND" logic).
If none of those pads were marked, I would have said B- in the middle, C- on the bottom one and P- on the top one with the shunt. Then, the charging and discharging controls would work independently, but the BMS would only be able to handle half the power because there would only be 4 mosfets for discharging.
I can see why you are worried about water proofing Usually packs like yours are double shrink wrapped.
I second d8veh's comment on the weight distribution. Personally I would have made two 24 V packs and put them in series. Each pack in the bottom of a pannier on either side and thus down at about axle level. Your leads come out the bottom of the panniers and along the chainstays to the controller. The lead permanently attached to the frame and the plugging and un-plugging happens inside the pannier bag.
Do the gear/brake cables pass the controller box OK? I ask because I have the same controller box and I like the idea of putting it under the frame like that when I get around to building my custom in frame battery box.
Usually packs like yours are double shrink wrapped.I second d8veh's comment on the weight distribution. Personally I would have made two 24 V packs and put them in series. Each pack in the bottom of a pannier on either side and thus down at about axle level. Your leads come out the bottom of the panniers and along the chainstays to the controller. The lead permanently attached to the frame and the plugging and un-plugging happens inside the pannier bag.
Do the gear/brake cables pass the controller box OK? I ask because I have the same controller box and I like the idea of putting it under the frame like that when I get around to building my custom in frame battery box.
The N- pad is a common Source for the 8 HY1808 MOSFET and is at 0volts
There is a YouTube video of a bloke decrying these things and, as part of his justification, notes that the heat dissipation capacity to really get a hold of a wayward cell is insufficient. I keep proving that and use my iCharger 1010B to sort the cells out so why not find a simple non-balancing BMS and use the iCharger to balance charge the battery? That means taking a 10 cable plug out of the battery pack ....
You guys are of course correct, weight distribution is terrible, my spoke tightening mission last night is proof of that... I can certainly bring the whole thing clockwise a fair bit but obviously cant lower it, the rack is at that angle as i have a kiddy seat that goes on the rack and needs that angle, didnt want to change it... But i know it must be done.
If i play with the bike any more this week shes defo going to leave me so il have a think and post pics of my changes in a few days..
Also re that battery, should be arriving tommorow (just ordered one) il test and post what i find.
You guys know the deal tho, if something seems too good to be true etc etc
If i play with the bike any more this week shes defo going to leave me so il have a think and post pics of my changes in a few days..
Also re that battery, should be arriving tommorow (just ordered one) il test and post what i find.
You guys know the deal tho, if something seems too good to be true etc etc
If you are going to buy loads of them I think you will find one of these handy.
http://www.pedelecs.co.uk/forum/threads/18650-cell-charger-tester.26851/#post-357385
D
Deleted member 4366
Guest
<ake your own rack out of steel or aluminium tube from Wickes and some 3 mm or 5mm plywood. You'll be surprised how strong and rigid it is when finished. Steel is probably better for a battery as heavy as yours. It's dead easy. Just cut the tube to length, bash the ends flat and drill holes. the plywood should be the same shape as the inside bottom of the bag. When everything is drilled, you put the plywood in the bag and bolt through:
Thats what i need to do D8v, actually found some lower holes a the frame and managed to drop a couple of inches and tilt a bit forward, this monster in going to look naff how ever i put her on prob should try and do a series adaption to it somehow
Below are the pictures, bit better but no good really.
Below are the pictures, bit better but no good really.
D
Deleted member 4366
Guest
Who would of belived that people online lie!
I could be wrong on this but pre-testing im going for 3600mah
See what the imax reveals.....
I could be wrong on this but pre-testing im going for 3600mah
See what the imax reveals.....
