Lipo pack config and range question

[NeilP]

Having decided on using Lipo packs from like the Turgny packs from Hobby King, I have begun to wonder about configuration.

I DO NOT intend to buy 12 packs...but for the purposes of this question I can describe what I am asking better if we use the number 12
So imagine 12 packs of 10s @ 5Ah. So 37volt per pack. max available power available to 100% discharge would be 37v x 5 Ah = 0.185kWh 12 packs = 2.2kWh

So these packs could be put together in many different configs

All series. so 5Ah and 444 volts
2p6s 10Ah 222 volts
3p4s 15Ah and 148 volts
4p3s 20Ah 111 volts
6p2s 30Ah and 74 volts
12 parallel 60Ah and 37 volts

OK, so the higher voltages of the first two (three?) count them out

Also assume for each pack config, the bike is ridden to the same, speed along the same route. So for the higher voltage packs, keeping the speed down to the

If you are to drive the same route everyday...assuming nil wind and traffic problems..each journey should require the same power requirement in kWh...correct ?

So assuming all of the above... Batteries hold the same power capacity what ever config..and route requires the same power requirement, and assuming you ride to the same speed and style with all configs.....

Which is the best pack configuration to go for?

 

[dogman dan]

The one that best matches the speed you would like to ride. Using the speeds common for a 9 continent hubmotor as an example, if you want 20-23 mph, 10s lipo. 25-27 mph, 15s lipo. 20s lipo gets you a few seconds at 40 mph, but mostly you will have 35-38 mph. 25s gets you into the 45 mph ballpark.

Why? because controllers get less wear, and use less energy in the form of waste heat when at full throttle. So set up your bike to go what you like, full throttle. This is not much of an issue when dealing with 36v, but at 100v it can be. Also, at 100v my racing bike acts a bit like it just has an on off switch. you can go 45mph, or you can go 35 mph, but 10 mph is nearly impossible. there is no 10 mph setting, the lowest speed is pretty fast so it makes any kind of riding slow you may need to do pretty difficult.

Ranges won't differ dramaticaly between two different voltages that are not too far apart from each other, such as ride 20 mph on 36v compared to ride 20 mph on 48v.

Btw, we like to use the cell number when discussing batteries, so your 36v battery is 10s. 48v battery is 15s. 72v battery is 20s.

 

[NeilP]

OK, thanks, understood.


So what I will need to do, is build the bike up, see what speed it does in diffferent configs, and then see which arrangement suits best.

we like to use the cell number when discussing batteries, so your 36v battery is 10s. 48v battery is 15s. 72v battery is 20s/quote]

Yes, I sort of realised that and was wondering about going back and change it after I posted, but thought that since I was referring to how I was going to join up individual ready made packs, it made more sense to say how I was wiring the packs together rather than individual cells.
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