Recent content by battman

Overview This project provides reliable and scalable monitoring of temperatures through one or more digital sensors with results shown on a 4 digit LED display. The initial implementation has been used to monitor temperature at 12 points within an existing battery pack. Usage On power up, the...

Thanks. I chose that chip because it's cheap and easy to program via it's high level Basic language support. Even using Basic, the performance is more than sufficient for this application.

Hi Folks, This thread describes a circuit to take the signal voltage from a 5V throttle and remap that voltage under software control of a Picaxe chip. I have an electric bicycle with a Grin Technologies Phaserunner V2 with a single throttle providing both drive and regen braking. With this...

It will not achieve 100mph on flat ground, in still conditions, with 8000W. That would require at least double that power. Perhaps they mean it is rated at 8000W continuous with much higher peak power available, but they don't make that apparent in the specs and even if that is the case, that...

I only saw this just now http://lanesplitter.jalopnik.com/visionary-motorcycle-designer-racer-michael-czysz-pass-1775647380 Very, very sad. This guy was a wonderful, inspiring visionary.

+1 on the insulation if you can take your pack indoors on a hot day after riding. I live in Phoenix and have a 36Vx15AH pack inside an aluminum box that I insulated to protect the cells against vibration and shock. Turns out that this insulation has a significant added benefit for limiting...

Ha, yes it is ugly. Maybe a coat of paint would help? :lol: I'm done with the initial version of the windows and MCU coding, links to the source code for both are in the post. But I'm still open to bug fixes/ improvements of course. I may take you up on your very kind offer of help...

Hi Folks, Motivation for this project was similar to the MAX11081 BMS I put together last year (http://www.endless-sphere.com/forums/viewtopic.php?f=14&t=56937&p=849127&hilit=max11081#p849127), namely bad experience with commercial BMS and looking for something simple enough that I could build...

For the lead acid, 120AH at 60lbs would be 53Wh/Kg which is not a credible energy density for this type of battery even under "ideal" conditions (e.g. discharging at one milliamp at 25 Celsius).

There isn't necessarily anything wrong with the pack. I've seen the same behavior after charging on packs I made from both A123 20AH cells and Headway 40152 cells. In both cases I still had full capacity. My current 40152 pack sits at 40.2V after charging and doesn't drop further. What...

Hi Folks, Since there can never be too many different BMS implementations, I'd like to add a MAX11081 based one to the pile! At the time of writing, Googling for MAX11081 doesn't turn up much other than spec sheets, short news articles and a couple of short references of Endless Sphere, so...

Could you provide links to some suitable sources in Australia for these? Is there anywhere local that has some of the items you need to avoid shipping costs? That said, I'm probably more at the braided line level of contribution than the complete front wheel end of things! How do we avoid...

Would you entertain the idea of receiving a (modest) financial contribution towards this project? I really want to see it happen. I'm not going to be putting together something fantastic like this myself as much as I would like to. So the next best thing I can do is live vicariously through your...

Kool-aid drinker here :wink: ... This summer the ambient temperature will reach 110F and possibly more here in Phoenix. Under these weather conditions my pack could get warm enough to potentially degrade the cells. I am looking at experimenting with wrapping my pack in PCM material (maybe a...

You will likely see reduced cycle life, reduced capacity and increased IR below 10C. I never charged as low as 0C, probably 3-4C and, if my A123's are representative, it's just not worth charging them in those conditions for the hit the cells take.