I picked up a B&D 24V push mower for free. It needed batteries and a charger. I removed the charging circuit & batteries and replaced the batteries with two sets of GBS 20Ah (http://www.kta-ev.com/Battery_4_GBS_3_2V_20AH_cells_p/bat-gbs-lfmp20ahx4.htm) which are an almost exact size replacement for the lead acid batteries. I installed a self powered digital volt meter in place of the old analog meter and carefully bottom balanced the pack. I know when to stop mowing when the voltage reads 20V when not cutting grass. They bounce back to just over 3V per cell. I don't have a charging plug yet so I still have to remove the cover and charge the batteries with my bench power supply. Charging to 3.4V per cell average means I don't have to worry about overcharging the cells. Yes, I checked. It seems like it just runs for ever. It could mulch mow the yard of a 1200 ft^2 ranch style house on a 6000 ft^2 lot (I'm not sure of the lawn area) and still have energy left.
On Mon, Apr 28, 2014 at 9:58 AM, Michael Ross <michael.e.r...@gmail.com> wrote: > I have an old simple ICE push mower, that might be worth converting. > > Can anyone recommend the sort of motor I should look for? > > Re-purposing a motor would be nice. > > I would use LFP batteries. > > What about the shock of the blade hitting something nearly immobile? That > is a lot of shock that small engines are able to handle - special > consideration in the regard with electric motors? > > Mounting the blade seem non-trivial? Hints? > > Thanks! > > I just saw a Li ion powered mower on line for $500. supposed to run for 45 > minutes and charge back in 30. That sounds like a practical target. 48V > pack. Weighs 62lb. > > Any thought on this side of the equation? 36V? 60V? Capacity needed to > go 45 minutes? > > -- > Don't believe everything you read on the Internet - Abraham Lincoln > > A public-opinion poll is no substitute for thought. > *Warren Buffet* > > Michael E. Ross > (919) 550-2430 Land > (919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Google Phone > (919) 631-1451 Cell > (919) 513-0418 Desk > > michael.e.r...@gmail.com > <michael.e.r...@gmail.com> > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140428/7e307136/attachment.htm> > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > For EV drag racing discussion, please use NEDRA > (http://groups.yahoo.com/group/NEDRA) > -- David D. Nelson http://evalbum.com/1328 http://www.levforum.com _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
