Oset Batteries Lithium (LiPo) Conversion Directions

[lennie]

Agreed. The bms and how to make charging simple is the most complicated part.

[dale666]

Amazing work everyone.

I knew nothing 3 days ago and now from reading all 30 pages and other forums, I am 90℅ sure on what to do now, just need a few things confirmed before I decide on what to purchase. 

I'm buying a 2017 12.5r at the end of next month and want to lipo straight off. Looking for weight saving as for my 4.5yr old and 3yr old, I'm expecting my oldest to grow out of it by next year and then I'll be getting him a 16" so they will both have one.

For now just looking at a 24v setup.

Looking at 8 3s 4ah-6ah (haven't worked out what's the best for weight yet) and going to put 2 lots in P, the S them up, so will have a 22.2v with 8-12ah then have 2 of theses.

Both have never been on an electric bike before but the oldest rides his balance bike like it's nothing now and also just started on a pedal bike with ease, but the youngest is getting there on the balance bike (and quicker than his older brother at the same age) but is a year and 4 months behind so want to be able to run one pack at a time for the first few weeks till there uses to it, then I'll add both sets.

Does anyone have the dimensions of the oset 12.5 battery compartment?

Thanks in advance

[dale666]

Dimensions of the bike are a big part of my battery choice as want it built and ready to go the day I get the bike.

So with the 8 x 3s lipo I was taking about, am i right in saying this is the correct way to put them together

So if I P1+2 and P3+4 using theses https://hobbyking.com/en_us/xt60-harness-for-2-packs-in-parallel-1pc.html

This would give me 1+2=A and 2+3=B.

Could I just plug A+B into this https://hobbyking.com/en_us/xt60-harness-for-2-packs-in-parallel-1pc-1.html and that would give me one single pack (say 4 x 5000mah = 20ah), would this would be the correct and safest procedure of building it?

Assuming this is right and I have done this twice over (so now have 2 x 20ah 11.1v) is it just a case of plugging both of these Into this https://hobbyking.com/en_us/xt60-harness-for-2-packs-in-series-1pc.html and that is the correct and safest way to contact these in S to get the desired 22.2v 20ah.

I understand I will have to change the connectors on the bike and maybe some others as well but just want to make sure if have understood it all before I send the money, think I got it sorted just not 100℅ if it can be configured in that way.

Building my shopping list at the moment so any advice is welcome.

[gwhy]

or if it will fit just get one of these

https://hobbyking.com/en_us/multistar-high-capacity-6s-20000mah-multi-rotor-lipo-pack.html

the less interconnections you have the less room for error.. you may want to source a 6s bms for charging and basic battery protection.. you can bypass the current limit on most bms's for the discharge so you dont need to source a very expensive one..i think hobbyking sale a 6s bms but not to sure what the max charge current spec is.. 

 

4A max charge bms  https://hobbyking.com/en_us/6s-li-ion-pcm-charge-4a-discharge-10a.html

10A max charge bms https://hobbyking.com/en_us/6s-li-ion-10a-pcm.html

Edited February 11, 2017 by gwhy
added bms options

[dale666]

So it would be a safe configuration as long as I didn't plug anything in the wrong way ?

I did see that big battery but was thinking about what someone said earlier (possible you) about if a cell go's bad then would have to scrap the hole thing, plus it's not stocked in the UK by the looks of the hk website. 

I was thinking about either 2x6s 8ah or 4x3s 8ah or 8x3s 4ah, all giving me 22.2v 16ah. Going to work out what is best for weight, availability and price to decide but I get what your saying about less connectors. I would mark and label everything and be extra careful when charging everything and putting it back together.

I'm looking at 2x https://hobbyking.com/en_us/turnigy-reaktor-250w-10a-1-6s-balance-charger.html

And Will add a voltage meter for on the bike to keep an eye on overall and check cell levels before charging.

And was thinking of powering the 2 charger with something like http://www.kingslynnmodelshop.co.uk/Batteries_and_Chargers-Power_Supplies/c66_77/p4480/Pro-Peak_13.8v_Dual_Power_Supply_30A_415W/product_info.html

Would this be man enough to power the both with a max 415w if the chargers are 250w each?

 

[dale666]

1 hour ago, gwhy said:

or if it will fit just get one of these

https://hobbyking.com/en_us/multistar-high-capacity-6s-20000mah-multi-rotor-lipo-pack.html

If I know the battery compartment dimensions I could probably find one in the UK of the spec, don't suppose you know?

 

[gwhy]

yes that is the only draw back with having one big perminant pack , if a cell ( cells ) goes bad in the string then it will require battery surgery to remove/replace the bad cell (cells) this only applies to cells in P and the more P cells you have the more of a possibillity it would be for a cell to go bad , so this is something that you need to think about.  If you have a bms then you dont require a balance charger , the bms is permantly connected to the battery and will all ways balance the cells when charging and will also prevent any cells from over charging. If you also bypass the onboard discharge current limit on the bms it is possible to have it control the bikes relay so should any cell drop below the safe level the bms will turn the bike off ( if you want more details about this let me know ) . you can still have a volt meter on the bike as a fuel guage.  you can buy 24v CC/CV 5A psu's for around £20-30 that will be ok for a charger that is already mains operated ( they have a voltage adjustment pot on the psu as the output voltage will need to be adjusted to the correct voltage.... for 6s you will need 25.2v output ) or by a ebike li-on charger and ask for th evoltage to be adjusted. if you have the bms setup then there will be no need to diassemble the pack for charging , it becomes a plug'n'play setup.

 

No i dont know th emax size of battery that can be fitted, sorry.

this would do for a 24v charger .. ( but you would have to use a bms )

 http://www.ebay.co.uk/itm/Adjustable-DC-0-30V-0-5-10A-Power-Supply-Precision-Variable-Digital-Lab-SA-UK-/262749264649?var=&hash=item3d2d139b09:m:m1J_LguXIITfnH-3ydJ-Yzw

 

also i was just looking on ebay and you can buy a 60A 6s bms from china for £12.. ( if your prepaired to wait for it) , this can be just wired up as it should be to the 6s and 60A should be fine for the 12" 24v oset

http://www.ebay.co.uk/itm/6s-24v-Li-ion-Lithium-Cell-60A-18650-Battery-Protection-BMS-MOS-Board-w-Balance-/331944218203?hash=item4d496ace5b:g:wLsAAOSwV0RXtZhj

 

side note:  if you opt for the psu i linked to as a charger then i would set the voltage then glue the adjustment knob so it can not be moved, or remove the knob alltogether.  

Edited February 11, 2017 by gwhy

[dale666]

Thanks for that, do I need a BMS for lipo's? I thought they were only needed for building li ion. Wasn't going to bother with BMS, just build a lipo pack that I will monitor myself. I don't trust it will be working as no indication of anything till the pack is knackered. 

So with the lipo in mind, will the 2 chargers I mentioned earlier be OK for the job with that PSU I also mentioned?

I will run a fuel tank on the bike and do all the monitoring once the day if over, will also get a cell checker so I will be the battery monitoring system.

Sorry if I have misunderstood anything.

 

[dale666]

If I P4  3s batterys together will the charger read that as a 3cell pack or a 12cell pack ?

[gwhy]

BMS is used for all li chemistery batteries, but you can monitor them yourself as you have stated, a bms takes all the hard work out of it.. you dont need 2 chargers as you are only using 6s so you can charge them as one complete pack.  so yes a 450W psu should be fine for one charger . if you P4 3s packs then this will still be seen by the charger as a 3s battery but with 4x the capacity..the nice thing about using a bms is that the pack should never become totally shot as it will protect the rest of the cells from futher discharging, yes the battery will not work but will be saveable.  you will need LV cell alarms for each cell group within the battery when you are using it and you must remove the lv alarms when not in use ( or they will drain the battery )  a bms is always connected and instead of a alarm it will just turn off the battery should any of the cells become to low. 

[dale666]

Just found these https://hobbyking.com/en_us/turnigy-graphene-8000mah-6s-15c-w-xt60.html

Looks like a good pack and would only have to parallel 2 together for the desired 22.2v at 16ah and only £50 each so could even buy 3 and have a 24ah pack. They are a bit heavier than I was thinking of using but look good, have the xt60 connectors (want an easy click together the first time then when I get the 16" I'll make all my own connectors) and say they are in the UK. Would still buy the 2 chargers I mentioned earlier and the PSU unless anyone can advise on anything different.

I take it at 15c for the little 24v will be fine? Sure someone said it's 40a con and 50a burst

As said earlier on I think I've got it, so really I'm just looking for confirmation.

[dale666]

So with this I would charge the hole 6s 2p on one charger. Sweet just need a charger that can do the hole pack in 1hr, could you advise on the best that's not stupidly expensive. 

I've got £300 for the project as was going to buy a boost bikes setup but decided I could build so much more for the same money. So looking like £150 for bats and everything else so leaves the same for charger and PSU unless I get a 240v setup as will only be charging at home.

[gwhy]

if you go down the route that i suggested i.e bms and the digital psu then you can get 4x 16ah 6s batterys and the charger , if you go for the10A psu this will give you a charge time of around 1-2hours charge time from completly flat to complty charged and balanced a 5A psu these times would be doubled.

 

https://hobbyking.com/en_us/multistar-high-capacity-6s-16000mah-multi-rotor-lipo-pack.html

 

im sure i have seen them in the uk web site but cant find them at the mo ... i know they used to sell them cos i have 8 of them :-)

 

nope just looked through my orders with hobbyking and i got them from HK but i must have got them quick without much fuss or i would remember.

Edited February 11, 2017 by gwhy

[dale666]

53 minutes ago, gwhy said:

 get 4x 16ah 6s batterys and the charger , 

Is this not a bit excessive 64ah lol

So with this setup with a 20a charger and PSU would that charge and balance the hole pack in 30-60 mins at 64ah ???

Not going to bother with the BMS, I want to do all the work myself.

Going to make up some male spades to xt60 for the main wires on the bike, also wire the voltage meter on the main loom so only powers up when the battery pack is fitted.

I will be using 2×6s 8ah to start with

https://hobbyking.com/en_us/turnigy-graphene-8000mah-6s-15c-w-xt60.html

Then putting them in parallel with one of these 

https://hobbyking.com/en_us/xt60-harness-for-2-packs-in-parallel-1pc-1.html

I will buy some extender cables for the balance ports so I can plug the cell checker in via this and that will allow me to plug and unplug as many times as I like without the risk of damaging the port on the battery side.

Job done.

Just can't decide on what charger and PSU, as I would like to charge it in under an hour if poss 

Job done.

 

[dale666]

Just found this https://hobbyking.com/en_us/turnigy-reaktor-30a-1000w-balance-charger.html

But not sure on the best PSU for it, any help would be much appreciated.

Thanks