Brammo Owners Forum

Brammo Enertia Discussion => Brammo Enertia => Topic started by: Brammofan on June 20, 2012, 05:28:02 PM

Title: A comment on "My first commute on my Brammo Enertia"
Post by: Brammofan on June 20, 2012, 05:28:02 PM

I posted a video many moons ago of a test run I did from my house to my office, and back again.  Even though it's about two years old, it still gets comments.  This is the latest one:

Quote

if you want your expensive batteries to last as long as possible before needing replacement you should not regularly discharge more than 50% so if you make this trip regularly if possible i would consider taking your charger for instance to work and plugging in there or taking this into consideration when buying your batteries and get enough ah to allow for this distance at 50%, i have started taking my charger to work even though my bike covers the distance and have noticed it performs better

If anyone (ahem...protomech) wants to talk to him about why he is maybe a bit off the mark, feel free to do so.  The video is here:

My first commute on the Brammo Enertia (http://www.youtube.com/watch?v=EP4DAlY7nUY#)

Title: Re: A comment on "My first commute on my Brammo Enertia"
Post by: protomech on June 20, 2012, 05:34:16 PM

You make it sound like I enjoy listening to the sound of my own voice..

The Valence datasheet for the U-Charge U1-12XP modules indicates 2500 100% DOD cycles until 80% original capacity (in standard test conditions; real world results WILL vary) .. or 78k miles @ 35 miles/cycle.
http://www.valence.com/sites/default/files/images/XP_Module_Datasheet__1.pdf (http://www.valence.com/sites/default/files/images/XP_Module_Datasheet__1.pdf)

They show a 10V cutoff voltage, or 2.5V per cell (nominal 3.2V). This is quite low - but as each module has its own BMS, the modules should be safe no matter how the Enertia uses them.

Note they actually show the continued pack capacity degradation down to almost 5000 cycles.. I recall the last datasheet I saw going down to around 3000 cycles. Perhaps they have more tests on them now. C/2 = 2 hour discharge, 2 hour charge .. 5000 cycles = 20k hours = 833 days = 2.3 years. 1 40 Ah module = 512 Wh = ~$500 cost .. 5000 cycles = 2.22 MWh = $222 @ $0.10/kWh. A lot of testing.

Title: Re: A comment on "My first commute on my Brammo Enertia"
Post by: EmpulseRider on June 20, 2012, 07:23:30 PM

2500 cycles to 80%... thats really good! Brammo is quoting 2000 cycles for the Enertia battery: http://www.brammo.com/enertia_specifications/ (http://www.brammo.com/enertia_specifications/)
Looks like I will need to update my app for the Enertia either way, as Im showing 1500 there.