RC Lipo Query

[Scottyf]

I'm hoping a few of you will be able to help with this.

I'm contenplating using LIPO as a backup battery now that my 36v Battery is backup and running.

As I never use over 3amp's on any one journey on my commute I've been thinking of buying two 6S 5000mah lipo bricks (22v each). Placing them in series and using them on the bike. I also have a Watts up meter installed so I can monitor the Voltages and Amp usage.

LIPO is also avaliable locally sourced so I dont have to wait around and also allows flexiblilty to add parallel packs should I want to increase range in the future. Its also very light and has a high "C".


Would I be right in saying I could litterally buy two lipo bricks. Attach them in series and use them on my Ebike. Also use a 6s charger and charge each brick seperatly or connect them in parallel and charge them up?

Any help is appriciated
Espcially as LIPO can be a bit dangerous if over charged. But I would really like to learn more about these batteries as the weight and flexibility of the packs is great.

 

[NRG]

Yes, its possible. You've identified the danger of overcharging so a good RC balance charger will be needed, charge the packs separately either in turn or use two chargers.

The real danger comes when these cells are over discharged and then recharged to full capacity. its in these scenarios where the packs can swell or combust without warning so its essential IMHO that you provide some form of cell based LVC monitoring. Its not enough to rely on the controller LVC as a) it wont match the Lipo pack voltages and b) its LVC on the pack as a whole not individual cells.

There are loads of devices available like the Cellog units that can emit an audible warning or be configured to operate the brake cutout when a preset low voltage level is set. You will have to be handy with electronics to wire up a suitable circuit to use the brake cutouts.

For the LVC itself I'd go no lower than 3.2v

 

[Scottyf]

I ended up reading alot on a few rc forums and it doesn't sound that bad. It's not as straight forward as buying a battery but the flexibility sounds exactly what I want.

As I've figured I won't stop tinkering withthe bike but really want light weight packs.
I never use past 4 amps in anyone one day and currently Riding without to keep fit.
But the idea of an electric back pack with only a could kg of lipo is very appealing.

Going to go for it and I'll keep you all undated
Also keep you updated if I end up in a fire ball!