regen braking excess

[rotorblades]

what does an x2 do with excessregen power when the batteries are already full? like twoblinking greensthen going downhill. =burn it up in motor windings?

[KSagal]

Back in the early days of 2003 and 2004, I used to run my e-167, with NiMH batteries, which had about 1/2 the range of current LiIon batteries.

One of the tools I used to extend my range, was a temperature sensor I had on my machine, actually two temperature sensors.

One was mounted to the battery(ies) directly, and reflected the battery temperature, and the other was an ambient air temperature sensor.

I found that running hard and fast, like full speed up hills generated and increase in temperature at the batteries. Additionally, going too fast down hill also increased the temperature in the batteries.

I surmised that taking too much energy and trying to either remove it from, or add it too the batteries, caused a corresponding waste of energy in the form of heat. By taking effort to not allow the batteries to heat up (my target was no more than 10 degrees over ambient air temperature) I could effectively increase my range, or at least reduce this wasting of potential energy by converting it to heat.

I shared my findings with Doug Field at the time. He confirmed my theory that I could increase my range by keeping the heat generation to a minimum.

Now, skip ahead a decade.

While many things have changed, I suspect many have not.

So, as is my style, I used many too many words to answer your question. I believe that excess regenerative energy is consumed by generating heat. This is minimized in modern software driven segways by speed limiting the down hill power generation, but the point remains. Too much energy in either direction will generate heat.

At least that is my understanding of the situation.

[jgbackes]

At some point going down hill with full batteries will throw an error. The heavier you are the sooner you get the error.

As I recall it was an over temp error.

jeff

[rotorblades]

Originally Posted by KSagal

Back in the early days of 2003 and 2004, I used to run my e-167, with NiMH batteries, which had about 1/2 the range of current LiIon batteries.

One of the tools I used to extend my range, was a temperature sensor I had on my machine, actually two temperature sensors.

One was mounted to the battery(ies) directly, and reflected the battery temperature, and the other was an ambient air temperature sensor.

I found that running hard and fast, like full speed up hills generated and increase in temperature at the batteries. Additionally, going too fast down hill also increased the temperature in the batteries.

I surmised that taking too much energy and trying to either remove it from, or add it too the batteries, caused a corresponding waste of energy in the form of heat. By taking effort to not allow the batteries to heat up (my target was no more than 10 degrees over ambient air temperature) I could effectively increase my range, or at least reduce this wasting of potential energy by converting it to heat.

I shared my findings with Doug Field at the time. He confirmed my theory that I could increase my range by keeping the heat generation to a minimum.

Now, skip ahead a decade.

While many things have changed, I suspect many have not.

So, as is my style, I used many too many words to answer your question. I believe that excess regenerative energy is consumed by generating heat. This is minimized in modern software driven segways by speed limiting the down hill power generation, but the point remains. Too much energy in either direction will generate heat.

At least that is my understanding of the situation.

my question wasnt worded very well. i doubt segway would bleed off extra charge bby heating atteries-lithium im only guessing using up some for hill holdbback it must have to use someup on opposing windings or?

[KSagal]

Originally Posted by rotorblades

my question wasnt worded very well. i doubt segway would bleed off extra charge bby heating atteries-lithium im only guessing using up some for hill holdbback it must have to use someup on opposing windings or?

The segway does not heat the batteries for a purpose of consuming energy, it is a result of having energy with no place to go.

That is the reason segways speed limit on the way down hills, to reduce the excess energy that has no place to go.

There are several threads on this topic on this forum. Some had suggested there should be an incandescent light that would consume the energy, others had other ideas of what to do with this excess energy. Look around and you will find those threads.

I believe the bottom line to your question is that the segway does not really have an adequate answer to what to do with excess regenerative energy from long downhills, and that is why the newer segways are so much more speed limited on downhills compared to older ones, to reduce the generation of more energy than can be absorbed by the batteries.