gwhy

if you have 1 psu to power all your chargers ( at the same time ) then the psu needs to cover the total wattage of all the chargers added together i.e if you run 2x 150w chargers from the same psu then the psu needs to be >300w ( the psu also needs to be the correct voltage , normally 12-15v output. ) when you P the batterys this increasese the capacity of the battery i.e 5ah in P with another 5ah = 10ah so if you P all 6x 5ah batterys to charge then this becomes a big 30ah 5s battery and if charging at a max of 7ah this gives you a total charge time of: total capacity (30ah ) / Max charge current (7A) = number of hours ( 4.2 hours + balance time ) yes you could use a good deep discharge lead acid battery to power the chargers but you need to take into account the current that will be pulled from the lead acid even the if the Li charger is only putting out 7A into 5s you will need a total of around 12A from the battery to achieve this so if looking to power a total of 300w worth of chargers ( dont matter what configuration ) then a total of 24A per hour is needed from the lead battery and if the lipo is going to take 3 hours to fully charge then the lead must be at least 24A*3hours=72ah I think if it was me deciding which way to go for a 36v lipo setup then I would buy a 10s charger and psu to drive it ( 300W is about the highest rate of charge I would feel is a good compromise between speed of charge and safety with a 15ah battery ) then the li battery can be permanently wired into its working configuration with just one big balance plug and have done with it, there will no having to split the pack to recharge.

As far as I know none of the oset range of controllers have regen or plug braking .. if anyone knows different then please post it up.

just a quick note about psu's to power the chargers ... the psu needs to be at least the Wattage as the charger i.e 300W charger then ideally needs 300W+ psu and this is where the expense can come in a single 350W 12v psu cost around £30-50 found cheaper but this is the average i have found but still needs to some work before you can use it ( ebay -delivered ) so this is where is might become cheaper to buy a bms instead of a charger as it would be a total of £30-50 for a 350W psu ( as above but the correct voltage for amount of cells) and the cost of a bms @ around $30-40 or a 60w 15v psu around £6.00 delivered each ( ebay - delivered ) there for 4-5 60w psu = the 350w psu @ a price of £30- delivered maybe can get the 60W psu cheaper if buying more than 1 one !! just had another off the cuff thought I wonder if you can P the cheapo 60w psu's you may be able to if they are not earthed ,uhmmm maybe I will look into it.

your running wiring still looks more confusing than it needs to be.. the charger in your link is a 300w charger so it will charge at a max of 300W a fully charged 10s lipo is 42.00v so this is how you can work out the max charge current for the amount of cells being charged. W= V x I so if you transpose that to W / V = I i.e 300W / 42v = 7.1A ( or there abouts ) so the charger can put 7A into your battery every hour ( 7ah ) So if you had a 7ah battery then its about a hour charge and a 14ah battery it will be 2 hour charge.. but this is into a totally flat battery ( which is never advisable to run down a battery especially a lipo beyond a 80% discharge for max cycle life span) so I take around 20mins off the fully charge times the balancing time at the end of the charge cycle can take ages and depends on how matched your cells are in the first place but it can be anything from a extra 30mins to 48hours+!!.. but i always work around to add a max of 1.5 hours on top of the charge time and if it goes beyond that time then I check cells and the charger to make sure everything is as it should be.

I cant find the link you posted earlier about the 2 10s chargers at hobbyking ( sure you post one :-) ) but both would do the job for charging a 10s pack without splitting so may be a viable option if cost is ok.. for the faster charger option you will need a matching psu to power the charger(s) that you decide to go with. 8wag wire is a bit big to solder to xt60 plugs and sockets 10awg is better.. can just about get away with using 8awg on xt90's your above diagram looks good on the charging side but looks more complicated than it needs to be for the running side.. let me see if i go a diagram somewhere that i can post up.. Edit: here you go.. treat each P block of 5s (in your case ) as a complete battery that can be permently wired together, yes it can be soldered ,, this includes the balance taps... then you just need the one Y connector/adaptor to connect to the bike.. some thing like this. this is a complete set of charge/discharge adaptors for lipo that are pre fitted with 4mm bullet connectors that allow easy connect/disconnect to the bike ( just 2 plugs ) its the Y bit that is the key to it :-) you will also have to buy some P balance adaptors... some thing like this http://www.hobbyking.co.uk/hobbyking/store/__27079__JST_XH_Parallel_Balance_Lead_5S_250mm_2xJST_XH_.html these dont tend to be very reliable so I make my own balance P adapors or just solder them for a permanent connection.. another edit: :-) When i was just looking through HK I saw these LV alarms that monitor the total pack voltage ( not cell level ) And just maybe you can use 2 of these wired in series permanently connected to the bike side of the battery connection .. I think i have a few of thoses alams here i will test and report back. http://www.hobbyking.co.uk/hobbyking/store/__7226__HobbyKing_8482_Battery_Monitor_5S.html they are cheap enough to take a punt as it should work but i would also put a small fuse inline with the alarm if you do try it. the main problem with using cell level alarms is that they can not be permently connected to the batterys as they will drian the battery down when no in use. The alarm plugs into the balance plugs which are not really designed to continuous plugging and unplugging and it will soon wear the plug creating other problems along the way.

using the 5s packs would be easier to charge as you treat a 5s pack as a individual battery ( do not matter how many you have in P ) then you would use 2 chargers ( if you get the 1-6 cell chargers ) if splitting the pack to charge. or you can buy 10cell chargers ( not sure if HK sell them ) a 10cell charger will charge and balance a 10cell battery without having to split the pack and if you have the 3s packs you could also get a 10cell charger to charge all at once without splitting the 3 individual batterys apart but if you go for the 1-6 cell chargers than you will need 3 chargers ... hope this make sense.

this points to the throttle .. but it would do this with sla's when you start to back off the throttle ( back wheel off the ground ) you say it do not slow down until you hit the zero stop on the throttle ? is the wheel still being powered or is it coasting until zero stop ? if the motor is still being powered as you wind down the throttle then its not the motor and still points to the throttle.. or its a torque only controller as the bike behaves with the sla's the im sure that its nothing to do with the controller .. I would defo get a replacement throttle first ( unless you know how to test its function using a voltmeter, its pretty easy to do ) but other than that it must be to do with controller,, but cant see why as there are a lot of people using the same setup as you ( Li on the 20" ) without issue so its all a bit odd... the only real difference between sla and li is the internal resistance of the battery so it could be that the controller sees this lower resistance as a fault but as i said lots of others are using Li setups without a problem. the controllers may be torque control controllers not speed based controllers and this will have very odd effects on the stand as there needs to be a load on the wheel for the controller to work correctly , but again it will be identical if using sla's. I know the EM has a torque base controller but it is set up for 50/50 i.e a torque/ speed setup There are many control methods and lots of different ways that they are implemented which all adds to the confusion when trying to find a problem.

do it do this with the wheel off the ground? if I didn't know you have a new battery then from what you have described above then I would go back to the original thing to check which is the motor and brushes.. but as it don't happen with the sla's then that makes it harder pinpoint the problem, the only thing I can thing of as to why it does it with your new battery ( if it is the problem ) the higher current/heat/arcing through the brushes may be making them stick in the holders and sticky/worn brushes can cause these symptoms

the 20" controller can do at least 7.5kw ... tested.. thats not saying that the motor can push out that much but thats what the controller can deliver so 100w must be a typo some bms has two stage protection, it has a hard cut off and a over current trip and depends on bms design to how it handles these 2 errors you could even have a weak cell in your battery causing it to cut out. As you say it works 100% with the sla's the the only thing it can be is your new battery/bms. The oset hardware is able to handle nearly double what your bms is rated for but your oset controller may not have such a high current limit than the one i was playing with so you really need to know what is the current limit on your controller to move forward .. from the info you have given then i would strongly suspect the battery/bms im not saying that it is not functioning correctly it just may not be up for the job. 60A cont for a controller that has a current limit of more than 60A then the bms will trip under certain conditions .. and 60A is not that high on a low voltage system. get your battery guy to disable the bms just to test or see if you can borrow another Li battery that dont have a bms ( most 20" users use Li ).. Motors will pull as much current initially as it can and normally the controller will limit the current,, a stalled motor will have very,very low resistance , even if it was as high as 0.5ohm you can see how much current it will pull if it was allowed to by using simple ohms law i.e 50v/0.5ohms= 100A but in reality motor are normally well below 0.5ohms, some of the motors i play with have a resistance of 0.01ohm so a stalled current would be 50/0.01=5kA the controller/bms needs to be able to limit this initial current and if the bms is hitting its limit before the controller then the bms will shut the controller down. These sort of problems are very difficult to pinpoint as its a chain reaction and sometimes the only way to find the problem is to use a data logger and get real time volt/current/throttle readings .. If it was not for the fact that you said it works 100% with the sla's then I would still be looking at the motor/throttle and connections

if the em throttle is a pot throttle and you are using the original oset controller then it will create a bigger dead spot ( there are ways around this.. PM me ).. the oset controller can and do cope with a lot more current than your bms can supply .. do you know what the current limit is set to on your controller ? I would say that a cont of 60A and peak of only 100A is very borderline to be able to deliver enough power to your motor. as I have said the oset 20" controllers can do more than 140A peak so you need a bms that can match this to be sure that the bms is not tripping. a 100A max is not ideal on a 20" would be fine on a 16" tho a different controller will not solve your problem ( if it is the bms tripping ) unless you turn the power down on the controller ( not speed ).

peak current would be around 40A (min ) and upto the current limit of the controller.. some test I done with the 20 controller peaked at well over 140A but this was a maxed out controller. so if your bms is only rated at 10A then this would explain why its cutting out. trust me the controller is more than capable..

the more batteries you have in series to run the bike means more connections that need to be disconnected/connected to charge the individual battery's and this increases the possibility for errors and worn connectors.. a 50w 6s charger will charge 1x 4cell 10ah (12v ) battery in around 2-3 hours , if you paralleled 3 batterys to charge then this time becomes 6-9hours... paralleling batterys to charge is ok but you need to be very careful because if you have a dead/low cell with a battery and you parallel with a good cell then the bad cell can pull down the good cell that is paralleled to and the more batterys that to parallel together ( just to charge ) then the chances of this happening is increased, also if you were to and#39;P' a fully charged battery with a flat battery this can have nasty results so you always need to check the individual cell voltages before each time you and#39;P' them together to make sure that they are all at more or less the same level. By using a charger for each battery this takes a little bit of the guess work away and also increases the charge time i.e 3x 50w chargers charging 3 battery's is a total charge time of 2-3 hours. If you had a charger able to to deliver the current then theses battery's can be charged safely at 1C which is around 1-2hours ( some people charge at 2C which would be around 0.5 -1 hour. There is nothing off the shelf ( that im aware of ) that will sound a buzzer for anything over 8cells so you would either have to use 3 warning buzzers ( one on each battery ) or make your own lv buzzer that monitors the complete working pack ... its very easy and only requires a handful of components I could supply a diagram of a very basic system if want to have ago. at which level you should run the batterys down to depends on the chemistry used, lipo should be discharged no lower than around 3.2v per cell and lifepo4 no lower than 2.5v per cell i.e if you have a lifepo4 12cell pack the voltage should never be lower that around 2.5 x 12 = 30v ( for a 36v lifepo4 battery ) and a lipo 10cell pack (36v) would be around 3.2 x 10 = 32v using a bms takes care of all this as it will turn the battery off if any one cell gets lower than its min voltage or turn the charger off if any of the cells get above the max cell voltage .99% of all the bms for lipo I have played with and spec sheets I have read, all allow the lipo cell voltages to discharge down to around 2.5v and this is to low and can cause problems down the line as these minimum voltages should never be exceeded. if monitoring the fully battery voltage then always use a conservative lv cutoff because you could have a weak cell within the pack that could be maybe 0.5v lower than the rest of the cells and if you use a cut of of 30v for the total then this could put the weak cell maybe be a lot lower than 2v.

54v is about right.. and no more than a sla 48v should be when fully charged which are around 56v hot off the charger. Ok my guess is that its the bms and that it can not supply the needed current to the motor... its nothing to do with the controller, motor or throttle if the bike is 100% fine on the sla's.. what is the spec of your battery/bms , peak and constant current. because the battery chemistry is better than sla the voltage will not sag so much and this in turn means it can deliver a lot more watts/power to the motor and this increase in power is tripping the over current shutdown on the bms a decelerate function on any controller is not a good thing as this in it self cause a lag between throttle movements .

the oset 20 controller i have played with had no issue with using li ... have your battery pack got a bms ?... the only time a controller will cut back the power is when it hit its current limit and this will be a gradual reduction in power and not on/off unless there is a fault.. with the output bms's can cut in and out, a faulty winding/brush in the motor can also cut in and out , a bad plug/contact can also cause this problem and so can a bad throttle.. its very unlikly to be the controller ... but dont rule it out .. and it will be nothing to do with using li as a battery chemistry did you say the back go backwards at on point ?

the number of cells that make up a specific voltage depends on the chemistry of the cells lipo cell voltage is 3.7, li-on is 3.6/3.7 and lifepo4 is 3.2 and they so for 36v lifepo4 then you will need 12cell i.e 12s and because the voltage per cell is higher with lipo/li-on you dont need to many cells i.e 9/10s there is not a charger that can balance charge all 12cells at the same time so you would need to split the 3 batterys every time you recharge , which is fine as long as every thing is going well with the condition of the batterys... when you get to splitting batterys to recharge then you really need to be on the ball as to know what you are doing and the reasons why you are doing it. I have always recommended having a charger for each battery if you are splitting the battery down to recharge.. its a much safer option

yes 3 of those will suit the 36v 16.. or if you want more capacity then get a total of 6 batterys to make up a 16ah 36v battery make sure 6 batterys will physically fit in the bike ( along with the bms ) to use a standard 36v charger you will need a 12cell bms http://www.ebay.co.uk/itm/36V-60A-LiFePo4-Battery-BMS-LFP-PCM-SMT-System-12S-12x-3-2V-eBike-Battery-12x-3V-/321048908605?hash=item4ac001933d you can shop around for a bms but make sure you get at least a 60A 12cell lifepo4 bms, a 100A will give a little more over headmaybe even go for the higest you can afford , that seller also does a 150A bms you will need to solder the battery together, fit charge/discharge leads and plugs and also fit the balance port plug onto the battery pack once assembled so you will need access to a soldering iron. if you do the 16ah route this will be equivalent to 6x earthx batterys so there is massive saving to be had. once assembled then you treat it just as the sla's as regards charging. edit: also buy 1 meter of red and black 10awg wire http://www.hobbyking.co.uk/hobbyking/store/__78181__Turnigy_High_Quality_10AWG_Silicone_Wire_1m_Black_.html http://www.hobbyking.co.uk/hobbyking/store/__78180__Turnigy_High_Quality_10AWG_Silicone_Wire_1m_Red_.html and i would use xt90 connectors for the main discharge plugs ( 1 to fit on the battery and 1 to fit on the bike ) http://www.hobbyking.co.uk/hobbyking/store/__24707__Nylon_XT90_Connectors_Male_Female_5_pairs_.html also get some heatshrink to cover all bear soldered joints on the plugs.. you will also have to buy a matching charge port socket ( for the battery ) to match you charger plug

So its not consistent... this makes it sound like it may well be the motor as gudah has already said. there are a couple of tests you can do yourself.. With the rear wheel off the ground and battery connected do it 100% always start when twisting the throttle very slowly ? With the motor wires disconnected ( and battery disconnected ) can you rotate the rear wheel i.e is there any very high resistant spots when rotating ( should be consistant ) , then try again with the motor reconnected ( should be identical resistance ). it could be brushes or commutator or worst case senorio could be a fried motor ( winding )

I would say the lag is 99% to do with the controller ( but always worth trying another throttle to confirm ) , has it always suffered from the lag ?.. how many adjustments do you have on your oset 20 controller is it one or two ? the only 20 controller i have played with had 2 adjustments , it had a max speed and a max power and the response curve ( as far as i know is hard coded into the controller on the 20 ) but there may be other controller versions for the 20.. if it has always had a lag then i would have a word with a oset dealer to see if they can reprogram the response ( if its reprogrammable ) .. as regards the cutting out with the new battery pack ... do the pack have a bms built in ?

The magura may not work to well ( if at all ) with the oset as the standard standard throttle its hall.. 99% of all hall throttles are linear but some are better than others.. also the maguras are just so over priced for what they are ( and dont tend to be very reliable electrically as the pot can and will become noisy effecting control). Any hall throttle will work with the oset but can be a bit of a gamble as regards the quality ,. As regards the lag .. the chances are that its nothing to do with the throttle unless you are talking about the dead band at the start of the twist.

yes pos to neg is series... the problem with these sort of setups is the charging procedure, as there is no balance charger for 12 cells so each of the 3 batterys will have to be charged individually or you have to make a charging harness so the 3 batterys can be put in parellel to charge as 1x 4s3p battery... thats why it may be best to buy a 12s lifepo4 bms and use the standard 36v charger.

if you dont also get a charger ( spesic chaarger ) tehn you would aslo have to get a bms for tehj complet setup... still drunks !!!! edir: ask me again when in sober.

NO you run t6hem in sewrial ,... opps... really drunk :-) sorry... run them in serial ..

You can save of the cost of the charger and psu if you invested in a bms for the lifepo4 cells this will then allow you to use a standard 36v charger.

i would still go down the route of using lifepo4 , they can be bought from Hobby king and look very simular to lipo but they do cost a little more. You still will have to wire them up but they are a little more forgiving than lipo, they have very simular performance/size and weight to lipo. you will need 3 of these for a 36v battery http://www.hobbyking.co.uk/hobbyking/store/uh_viewItem.asp?idProduct=32206 plus a charger and all the adaptors and connecting leads .. If you are in the uk .. if you do get batterys from hobbyking make sure you get them from the uk warehouse of you will get stung on postage and import duty.

A bms is a "battery management System" , Yes each 4 lifepo4 cells is a identical voltage as a standard 12v sla so you would need a total of 12cells in series for a 36v battery.