Oset Batteries Lithium (LiPo) Conversion Directions

[gwhy]

thanks for the replies guys, can you expand on this a little more?

 

how long would a charge for one of these batteries take?

what minimum voyage should I let the system get down too in use (i.e.: 30V) and is there a buzzer of something I could use for this warning?

cheers

 

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.

[bowser]

OK, i've read this again and think i'll stick with he Lipo's like everyone else in here.

here is a summary of what some guys are running, i'm deciding between the 6 battery setups listed below for my 36v bike.

which one would be easier to charge?

i'm interested in getting more run time rather than speed at this stage as my boys are still getting used to the bike and the touchy throttle

thanks

 

2 - 9S 5800 - 33.3v - 11.6ah - 2 in Series

10 - 5S1P 5000 -37v - 25ah - 2 in Series x 5 Parallel 

6 - 3SP1 8000 - 33.3v - 16ah - 3 in Series x 2 Parallel

6 - 5S1P 5000 - 37v - 15ah - 2 in Series x 3 Parallel

 

Edited August 15, 2015 by bowser

[gwhy]

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.

[bowser]

ok, getting a better understanding of it now. I knocked up this quick wiring layout for the bike running and also charging layout to give an easier understanding of the charging requirements and why the 5s is easier.

 

correct me if they are wrong

 

 

[bowser]

Ok, just mapping together what I need (can't decide on 15ah or 20ah at this stage)

 

thinking i'll end up with something like this

 

6 of these batteries (may add more later)

http://www.hobbyking.com/hobbyking/store/__14653__Turnigy_5000mAh_5S_20C_Lipo_Pack_AU_Warehouse_.html

 

XT90's for the charger and bike connectors

http://www.hobbyking.com/hobbyking/store/%5F%5F32153%5F%5FNylon%5FXT90%5FConnectors%5FMale%5FFemale%5F5%5Fpairs%5FAUS%5FWarehouse%5F.html

 

XT60's for battery loom connectors

http://www.hobbyking.com/hobbyking/store/%5F%5F43416%5F%5FNylon%5FXT60%5FConnectors%5FMale%5FFemale%5F5%5Fpairs%5FGENUINE%5FAU%5FWarehouse%5F.html

 

Red 8AWG wire for all positive cables

http://www.hobbyking.com/hobbyking/store/%5F%5F41952%5F%5FTurnigy%5FPure%5FSilicone%5FWire%5F8AWG%5F1mtr%5FRED%5FAU%5FWarehouse%5F.html

 

Charge pack x 2

http://www.hobbyking.com/hobbyking/store/%5F%5F18678%5F%5FLithium%5FPolymer%5FCharge%5FPack%5F25x33cm%5FJUMBO%5FSack%5FAUS%5FWarehouse%5F.html

 

Parallel charge boards x 2 - will install XT60's on it

http://www.hobbyking.com/hobbyking/store/%5F%5F44958%5F%5FParallel%5FCharging%5FBoard%5Ffor%5F6%5Fpacks%5F2%5F6S%5FBare%5FLeads%5FAUS%5FWarehouse%5F.html

 

 

Low voltage alarms x 2

http://www.hobbyking.com/hobbyking/store/%5F%5F44925%5F%5FHobbyKing%5F8482%5FCell%5FChecker%5Fwith%5FLow%5FVoltage%5FAlarm%5F2S%5F8S%5FAU%5FWarehouse%5F.html

 

I still need to source a good charger and 240v power supply  - open to suggestions, want something good

 

also, will it be ok to join the red wires like below using solder or should i use some fancy plug?

 

Edited August 16, 2015 by bowser

[bowser]

as for chargers (initially 1 then 2) which of these would you select with AUD $140 max, want something that will give a fast charge

 

Turnigy Reaktor 300W 20A 6S Balance Charger

http://www.hobbyking.com/hobbyking/store/__54860__Turnigy_Reaktor_300W_20A_6S_Balance_Charger_AU_Warehouse_.html

 

iCharger 106B+ 250W 6s Balance Charger

http://www.hobbyking.com/hobbyking/store/__45593__iCharger_106B_plus_250W_6s_Balance_Charger_AU_Warehouse_.html

 

or charge them individually

HobbyKing 8482 Quattro 4x6S

http://www.hobbyking.com/hobbyking/store/__19744__HobbyKing_8482_Quattro_4x6S_Lithium_Polymer_Multi_Charger_AU_Warehouse_.html

 

I plan on putting the batteries in the fire bags connected to the balance boards then just charge them either in banks of 3 or banks of 6 - guessing this should be ok

Edited August 16, 2015 by bowser

[ali210984]

I'm going to do 5s as looks easier to charge with 2 chargers and run

[gwhy]

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.

 

 

 

 

 

 

 

 

 

 

Edited August 16, 2015 by gwhy

[bowser]

here is the 10s battery I posted earlier, i was concerned with how long it would take to charge them all as one pack

 

http://www.hobbyking.com/hobbyking/store/__45592__iCharger_1010Bplus_300W_10s_Balance_Charger_AU_Warehouse_.html

 

 

 

also, I amended the diagram a little on the running side, this is a little simpler and should work?

 

 

 

 

 

[gwhy]

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.

[gwhy]

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. 

 

 

[bowser]

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.

 

 

thanks, appreciate the help.

 

does that mean if i use a 150W charger and charge at 5s using a balance board so all 6 batteries charge parallel i would still get 7ah, how long would this take to charge all 6 batteries?

 

150W / 21v = 7.1A 

 

i'm set on the batteries, but selecting a charger or chargers is harder than I thought, still thinking of using 2 chargers, maybe 150W. 

 

I'm guessing if I sourced a PSU of >300W (or whatever the charger is rated for) I could use it for both chargers?

or use a decent deep cycle battery with my standard car battery charger connected to it?

 

thinking of using 2 of these, struggling to work out which one though

 

HobbyKing™ X200 Touch Screen Smart Battery Charger 10A 6S V2

http://hobbyking.com/hobbyking/store/__58061__HobbyKing_8482_X200_Touch_Screen_Smart_Battery_Charger_10A_6S_V2_AU_Warehouse_.html

 

Turnigy Accucel-8 150W 7A Balancer/Charger

http://hobbyking.com/hobbyking/store/__15044__Turnigy_Accucel_8_150W_7A_Balancer_Charger_AU_Warehouse_.html

 

HobbyKing™ ECO8 150W 7A 8S

http://hobbyking.com/hobbyking/store/__15046__HobbyKing_8482_ECO8_150W_7A_8S_Bal_Dis_Cyc_Charger_w_accessories_AU_Warehouse_.html

 

HobbyKing™ ECO6-10 200W 10A 6S

http://hobbyking.com/hobbyking/store/__15045__HobbyKing_8482_ECO6_10_200W_10A_6S_Bal_Dis_Cyc_Charger_w_acc_AU_Warehouse_.html

 

 

iCharger 106B-plus 250W 6s

http://hobbyking.com/hobbyking/store/__45593__iCharger_106B_plus_250W_6s_Balance_Charger_AU_Warehouse_.html

Edited August 18, 2015 by bowser

[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.

 

 

[bowser]

you are right though, it would be a hell of a lot easier to charge them all at once.

 

300W 10A 10s charger - $181 - would charge them all in 3hrs (exc balance) as 3 in Parallel in series (10s3p)

2 x 200W 10A 6s charger - $216 - would charge them all in 1.5hrs (exc balance) as 3 in parallel, (5s3p x 2 lots)

2 x 150W 7A 6s charger - $122 - would charge them all in 2.1hrs (exc balance) as 3 in parallel, (5s3p x 2 lots)

 

question, when referring to balancing a battery, does it just balance all the cells in that battery to the same or would it balance all the cells in the charge group the same?

 

also, when looking at the charger specs, does this mean I will only get 10A if inout voltage is 18V meaning if I sourced a 12V PSU it would be significantly less output?

Operating voltage range: 11.0~18.0VDC

Charge current range: 0.1~10A

Edited August 18, 2015 by bowser

[gwhy]

with the 10s 300w charger you will be charging a complete battery (36v) that is configured as a 10s3p setup ( identical to how it will be running on the bike )

the 2x 6s 200w charger you will have to split the battery down to 5s3p for each charger

and the same with the 2x6s 150w chargers 5s3p  ( this is assuming each battery is 5cells and 5ah (5s1p) and you require 15ah i.e 5s3p

 

all the P cells within a battery ( it dont matter if is a 10s3p or 5s3p ) get balance to the same final cell voltage ( lipo =4.2v per cell and lifepo4=3.65v per cell ) 

 

if you took your 5s3p battery group and P that with another 5s3p group than that now becomes a 5s6p group and this is what you will need to do when using only 1 x 6cell charger to charge all the cells.

 

 

the nearer 18v psu will just mean that the psu dont have to supply quite as much current to produce the final output wattage..

 

its all about watts

 

if it was a 11v psu then it will need to supply  around 9A for 100w but if it is 18v then it will only need to supply 5.5A for 100w

 

so as long as it gets to the same wattage there is no difference.

 

 

 

 

Edited August 18, 2015 by gwhy