suggestions for 60V 20A.Hr capacity + chargers + BMS

[deetoau]

Hi All,

Collecting parts for my first ebike. recently ordered a BMC v2C motor. currently looking at these Turnigy batteries from Hobby king (22.2V 5A.hr) - would require 12 of (3x22.2V=66.6V and 4 x 5A.hr= 20A.hr) - not sure best wiring setup to enable foolproof charging / operating wiring configuration swapovers. http://www.hobbyking.com/hobbyking/store/__9176__Turnigy_5000mAh_6S_20C_Lipo_Pack.html

The alternative I am looking at is a ping single pack battery. http://www.pingbattery.com/servlet/the-20/60V-20AH-V2.5-LiFePO4/Detail I'm not sure which will give better battery life - lowest $/kW.hr x recharge cycles is attractive. The hobby king appear to be better for high discharge/recharge rates but my build is mainly for longer range (50+km) rather than high kW motor draw . The single charger from the ping is attractive. less hassle to recharge. I'm not convinced the ping charger provides equivalent battery management to multiple turnigy chargers (or similar). [ie http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=7028]

As a side note, I'm leaning towards 60V20A.hr instead of lower V & higher A.hr due to keeping the option for higher burst power for hills and keeping the Amps down - lower heat in motor and lower discharge rate from batteries will result in more efficient battery use. (as I understand battery chemistry behaviour) Good insulation practices obviously will be important - will be using a rated isolation switch and considering a rated Amp trip switch as well.

Given battery pack failure will inevitably involve an individual cell failing - the ability to take a cell out and continue to use the pack until a cell is replaced is VERY attractive. similarly the diagnostics on individual battery cells available with battery monitors does not appear available with the ping battery.

I saw a photo once of a plastic block machined with wiring connectors that enabled easy quick swapping of battery pack wiring from charging multiple individual packs to connection as an assembly for operating. Haven't been able to find it again.

thoughts/advice appreciated.

 

[999zip999]

So you have had experince with lipo and lipo charging. As that charger will take forever. Plus a barbaque to charge in.

 

[kudos]

I saw a photo once of a plastic block machined with wiring connectors that enabled easy quick swapping of battery pack wiring from charging multiple individual packs to connection as an assembly for operating. Haven't been able to find it again.

That was a build by Tench. Very clever.

If I was building this battery out of lipo and funnily enough, I probably am going to soon with the exact same batteries.

I would purchase a iCharger 306B , plus a 30A 24V PSU to power it.

I would then buy a ready made lipo harness from iceman at lipoconnectionsolutions.com or PM him on here.

You would wants a 3S4P Anderson one-block harness.

The Anderson connector block does all the hard work for you in that the charger cable is configured to pararllel the batteries when charging and the contoller cable is configured to series the batteries as required.

This leaves you with literally one connector, which makes connecting things up wrong, almost impossible.

Kudos

 

[K.E.Kopp]

I own a Ping 60v 15AH & included charger (also a 60v 10AH). Both have been in service now for a few years. I did have a couple of issues "out of the box" so to speak. The 15AH had a sense wire broken & the first 10AH had a bad cell. The chargers have seen two failures, be aware these seem to be pushed to the limit of the specifications of the components, your milage may vary : ) A good quality bench power supply was my solution.

All the problems were addressed by Ping he is good to his word & warranty.

In summary; a few hundred cycles never below ~50% and never charged or discharged beyond rating the batteries show no sign of degradation what-so-ever.