I made a couple posts about the MM E -1000, 1000 watt / 36 volt minibike Lithium battery upgrade in the ''MM front suspension thread'', & after finding interest about it from others,, I thought it best to just start a thread.
Will start again from the beginning ……..
Am getting the wife a MM E-1000 mini bike.
It comes with a 1000 watt motor, 15 amp speed controller, & 3 - 12 volt 15 amp lead acid sealed batteries that run in series, to make 36 - 39 volts & 15amps.
These batteries weigh around 26.5 lbs. together.
They are real ''boat anchors'', & the way they set in the bike, is pretty high up in the housing,, setting on a tray,,, giving the bike a high center of gravity.
12v lead acid batteries are not really designed for fast discharge & power consumption.
They are really made for being constantly charge regulated with an alternator ect…
Generally, constant high amp fast discharge ect. permanently kills them pretty quick.
The plan is to replace these with 2 - 36 volt 10s 4p ''10amp'' lithium ion packs with built in ''BMS'' circuitry, & run them parallel.
The BMS is a circuit board that is integrated on top of each pack under the shrink wrap covering.
It monitors the voltages of the pack, & has protection circuitry against over charge, & discharge.
Each pack has 40 lithium ion ''AA'' size cells, that are divided up in a combination of 10 sets of 4 that are wired together in parallel, 3.7 - 4.2 volts a set.
They in turn are wired in series of 10, to make 36 - 42 volts. ''42 volts fully charged''. ''4.2 times 10'' = 42 volts
The 10s 4p description means , ''10 series'' & 4 ''parallel''.
The BMS circuitry also regulates the charge current to the cells to balance charge each one, & also regulates for balance discharge, so the cells draw the same.
Now for the real goody …..
These packs only weigh 4.4 lbs. each, & 2 of these packs together, weigh a bit less than 1 of the lead acid batteries !
That is a weight savings of over 66%, & almost 20 lbs. !!
2 of these packs in parallel , still have 36 - 42 volts together, but the amp capacity doubles, ''20+ amps'' .
The electronic speed control that comes with the bike, is regulated for a max current input off the batteries of 15 amps.
Both packs together have a capacity of 1000 watts, as the motor & ''ESC'' are rated for.
The ''ESC'' with these 2 packs in parallel, ''36 - 42 volts'' , also will still think that it is tied in with the stock batteries, & won't hurt it a bit.
The extra capacity of the packs, can best simply be defined as - ''reserve when needed''.
Both packs will fit on the stock tray, & take up only about 1/2 the room.
Figure the run time will go up from the advertised 40 - 45 min., to around 1 1/2 hrs.
Performance gains should increase pretty noticeably also.
Looked on aliexpress this morning, & they have these packs on sale for $83.30 ea.
They come directly from China w/ free ship.
You also want 2 36v - 2 amp chargers, so you can charge the packs separate.
They are $9.35 ea. & free ship.
After that, all you need is a parallel battery harness with connectors, to replace the plug in series harness that comes with the bike.
They are very simple to make, using 12 gauge ''high strand'' silicone wire & XT - 90 connectors, ''these are used a lot with large electric R/C stuff.
That's all for now,, hands getting tired from typing . LOL
Ian
Will start again from the beginning ……..
Am getting the wife a MM E-1000 mini bike.
It comes with a 1000 watt motor, 15 amp speed controller, & 3 - 12 volt 15 amp lead acid sealed batteries that run in series, to make 36 - 39 volts & 15amps.
These batteries weigh around 26.5 lbs. together.
They are real ''boat anchors'', & the way they set in the bike, is pretty high up in the housing,, setting on a tray,,, giving the bike a high center of gravity.
12v lead acid batteries are not really designed for fast discharge & power consumption.
They are really made for being constantly charge regulated with an alternator ect…
Generally, constant high amp fast discharge ect. permanently kills them pretty quick.
The plan is to replace these with 2 - 36 volt 10s 4p ''10amp'' lithium ion packs with built in ''BMS'' circuitry, & run them parallel.
The BMS is a circuit board that is integrated on top of each pack under the shrink wrap covering.
It monitors the voltages of the pack, & has protection circuitry against over charge, & discharge.
Each pack has 40 lithium ion ''AA'' size cells, that are divided up in a combination of 10 sets of 4 that are wired together in parallel, 3.7 - 4.2 volts a set.
They in turn are wired in series of 10, to make 36 - 42 volts. ''42 volts fully charged''. ''4.2 times 10'' = 42 volts
The 10s 4p description means , ''10 series'' & 4 ''parallel''.
The BMS circuitry also regulates the charge current to the cells to balance charge each one, & also regulates for balance discharge, so the cells draw the same.
Now for the real goody …..
These packs only weigh 4.4 lbs. each, & 2 of these packs together, weigh a bit less than 1 of the lead acid batteries !
That is a weight savings of over 66%, & almost 20 lbs. !!
2 of these packs in parallel , still have 36 - 42 volts together, but the amp capacity doubles, ''20+ amps'' .
The electronic speed control that comes with the bike, is regulated for a max current input off the batteries of 15 amps.
Both packs together have a capacity of 1000 watts, as the motor & ''ESC'' are rated for.
The ''ESC'' with these 2 packs in parallel, ''36 - 42 volts'' , also will still think that it is tied in with the stock batteries, & won't hurt it a bit.
The extra capacity of the packs, can best simply be defined as - ''reserve when needed''.
Both packs will fit on the stock tray, & take up only about 1/2 the room.
Figure the run time will go up from the advertised 40 - 45 min., to around 1 1/2 hrs.
Performance gains should increase pretty noticeably also.
Looked on aliexpress this morning, & they have these packs on sale for $83.30 ea.
They come directly from China w/ free ship.
You also want 2 36v - 2 amp chargers, so you can charge the packs separate.
They are $9.35 ea. & free ship.
After that, all you need is a parallel battery harness with connectors, to replace the plug in series harness that comes with the bike.
They are very simple to make, using 12 gauge ''high strand'' silicone wire & XT - 90 connectors, ''these are used a lot with large electric R/C stuff.
That's all for now,, hands getting tired from typing . LOL
Ian