[QUOTE=frodus;5406]For the same power (say 7200W), you would either do 144V of 50Ah batteries, or 72V of 100Ah batteries and get the same power level. There’s no “savings”, but with higher Voltage, you’re using less amps, and keeping the peukert effect low… and it depends on battery and chemistry, all batteries are not created equal. I cannot answer the question. You have to have the peukert value of the battery, continuous amps useage and temperature among other things to calculate.
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Got it.
[QUOTE=frodus;5406]
First, you’re not calculating Ah right. You don’t multiply Ah by batteries. If they’re in series, its still only the rating of one battery. For example. 12 batteries is 144V. Say they’re 50Ah, the pack is 144V 50Ah and 7200Wh.
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I never knew this until right now.
[QUOTE=frodus;5406]
Wh is range, so 312V would give higher range. Say the car has a cruising Wh/mile of 300Wh, the 144V would give only 80% of its total Watt hour rating for a range of 89 miles. The 312V would give 80% of its total WH rating for a range of 129 miles.
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Makes sense, got it.
[QUOTE=frodus;5406]
The big issue is that you’ll never fit 155Ah (or 232Ah) of batteries in a car/motorcycle or even a truck. Thats over 2k Lbs. Most i’ve seen in lead is about 25kWh
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I’m going to have to disagree with you here, even if I end up looking the fool
[QUOTE=frodus;5406]
If you go too low, you won’t be able to spin the motor fast enough to get to the speed you need, but if you go too high, you’ll have no torque/acceleration. You need the motor torque curve to calculate this.
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Interesting
[QUOTE=frodus;5406]
where did you get that calculation? where’d the 4000 come from? LBS doesn’t equate anywhere in power calcs. P=V*I. Ah is calculated based on the battery itself.
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I screwed up, 4000 was an estimate of Ah, by adding them to 4030, not weight, but as you said the calculation was wrong because you don’t Ah when in series.
[QUOTE=frodus;5406]
Wh means that its the amount that you can discharge per hour to 100% discharge. If you have 1kWh, and you discharge it at 1000W, you take 80% of that (because you don’t want to discharge lead below 80%), and you can run for 48 Minutes. (800W/1000W) * 60minutes = 48 Minutes.
If you have a 33.4kWh pack, its really 26726.4Wh. From that, if you were to cruise at 300Wh per mile, and go 45 miles in an hour, you’d be using a total of 13,500W per hour. At this rate, you could run for 118Minutes (almost 2 hours).[/QUOTE]
My next step is to calculate what my specific Wh reqiurements will be for my conversion.
This really cleared up a lot for me, thanks.