Missed that one

 

So? 

 

Whos gonna be a test mule?

 

Its a expensive proposition for me since I have 2 boys (almost $800). Plus I just got a battery pack from Fiat 500e that I will be taking apart and maybe I can use these cells on the kids bikes.

 

Like this one http://www.fiatpartswebstore.com/products/gb/FIAT/500E/BATTERY-KIT-Hybrid/11241489/68225701AD.html?partner=googlebase_adwords&kwd=&origin=pla

it looks like you will also need a psu for that charger as it dont make it obvious if its mains operated.. !! that will bump up the cost even more!..

 

the cheapest option is the one i suggested further back in this thread.. i.e a ebike charger ( with adjustable voltage for the different types of chemistry @ around £50 for a 5A charger )  a bms for the cell count/type you want to charge @ between £8 - £25 a box to put it in some wires and plugs @ around £15 then if you want alarms and a display will be about another £20 on top.. so a very versitil charging setup for around £100 + a bit of time putting it together.

 

eg  my 10A 48v balance charger setup cost

 

£19.00 for the 10A CC/CV psu ( charger ) (ebay)

£9.00 for the 12s bms ( for lipo ) (ebay)

£6.00 for a nice box ( to put it all in ) (maplins)

£6.00 cheap watt meter (ebay)

£12.00 2x battery medics ( HK ) for monitoring the indivdual cells and/or increasing the balance current ( for a faster top off charge )

£8.00 2x HV alarms (HK) just for piece of mind

£10.00 for wire and plugs

 

so about £70  for a 48v 10A charger 

 

the 2 things that are unique for the voltage that you want charge is the charger and the bms

 

the 48v psu that I have can be adjusted to cover 11s upto 14s lipo 

 

just looking at that charger again yes it will need a addional psu to power it. 

The 10s appeared good at first glance but all the extras ruin it on cost. I'm still hoping the other batteries come back into stock before spring.

Morning guys,

You guys are really clued up! Well done for the info! I'm kinda new to the electrical scene (being a mechanical engineer). My sons been riding his 12.5 on lead acids for a year and a half now. He is now 4&1/2 and I've built a custom 16 for him that he has just started riding, I have tried to reduce as much weight as possible etc. its a pre 2013 36V. Its currently on lead acids but I'm ready to take the final plunge to Lipo's as my boy is super keen and limited run time is becoming a huge factor and I also want to reduce the weight. The bike wont last a the trials he is competing in at the minute (4laps of 8 sections). I don't mind tinkering but am looking for the simplest set up as it looks like my daughter will follow in her brothers footsteps.

 

I've read and re read this post and my head is swelling a bit with all the information... Has anyone posted an exact set up that I could copy that would suit my needs (apologies for the ignorance). I'm happy with doing the wiring but am struggling to get my head around the BMS and charging/discharging requirements.

 

Any help would be much appreciated

 

Cheers 

 

 

12 hours ago, dkiom said:

"I've read and re read this post and my head is swelling a bit with all the information... Has anyone posted an exact set up that I could copy that would suit my needs (apologies for the ignorance). I'm happy with doing the wiring but am struggling to get my head around the BMS and charging/discharging requirements."

I have made a LiFePO4 plug-and-play solution. I am in the USA and these power supplies are manufactured here in the USA and are a custom for this application. This is not some home-brew setup with HobbyKing power packs. This exceeds OEM specifications and has a two year warranty (pro-rated) on the power supply. This is the setup that I currently use in my son's 2015 Oset 16.0 Racing 36V. I am an engineer and do this as a hobby. I can put these together for about $335 USD and that is what I would sell it for as long as its going in your kid's trials bike and you are not trying to screw me by reselling it and making $250. Not sure where you are located, but if you are in Europe I would have to look into shipping.

Blessings,

MS

Edited January 13, 20179 yr by superpower

Here is a picture of the power supply.

The footprint is the same size as the SLA batteries the bike comes with but they are a little shorter in height - 3/4" shorter, to be exact. These weigh 2.6 pounds a piece for a total of 7.8 pounds. They just plug right in to where your original batteries were and you can even reuse the cloth cover to keep them clean. They are in a sealed ABS plastic case that is shock and water resistant.

Edited January 13, 20179 yr by superpower

Voltage: 36V - 3x12V

Capacity: 9 Ah this is LiFePO4 capacity which is equivalent to a higher capacity in a SLA battery

Max Continuous Discharge Current: 18A

Maximum Peak Pulse Current: 36A (2 sec.)

Dimensions: 5.875 x 3.625 x 7.50 in. Total

Weight: 7.8 Lb Total

Includes built-in PCM (protection circuit module) with internal cell balancing and management, protection from over current, under voltage (over discharge), over voltage and short circuiting, and integrated charging circuitry.

Edited January 13, 20179 yr by superpower

You can actually fit 2 of these in the 16.0 Racing if you want to run a ridiculously long time. You have to orient them a different way though.

how does this compare to OEM batteries? What kind of range improvement?

18A cont current is not very good and only 36A peak, what make of lifepo4's are they ? 

https://www.google.com/search?q=9+Ah+this+is+LiFePO4&rlz=1C1ASUC_enUS663US663&oq=9+Ah+this+is+LiFePO4&aqs=chrome..69i57&sourceid=chrome&ie=UTF-8

ok not that good specs for the price..  I would say that 18A/36A is not really enough for the oset16 .. maybe fine for a very small bike with a very light rider..  

Located in the Isle of Man, the young fella did his first trial on his 16 today and the battery's just lasted although it was quite a flat quarry which helped. Looking to learn the lipo tech really as I'll be in this for the long haul I reckon! 

 

It's the BMS charge and discharge requirements I'm unsure off. Nice pack though