Expo 2018/Drill Batteries

More-idiot-proof drill-battery charging, and upgrading poorly drill packs

Wookey has built proof-of-concept idiot-proof 1hr charger out of makita charger case and B4 35W autocharger They are £9

B6 50W charger (£11) would charge faster, but currently out of stock. Will buy if they return, otherwise B4 will have to do.

Tasks

* Test drill batts from 2017. Done (3 need new cells)

* Build 2 or 3 balancing autochargers. 
  Cannot source female batt connector, so must buy dead makita chargers (about £10 each). Got one for £8 during training w/e.

* Replace PCBs in 7 ('non-makita-charger') packs with own balance-connector board (about 3 hours per batt!): 2 done (April 15)

* Rebuild 3 new packs. Needs proper tab-welder (Tried soldering last year, and DIY tab-welding - not reliable enough). 
  Batt drilling current tested at 26A, so 15A cells needed. UK supplier is https://18650.uk/
  Can now get 2 and 2.5Ah 15A cells, so should be able to build 4 or 5Ah capacity packs for ~£40. Nickel tab-strip bought.

* Have bought/acquired parts for battery-tab spot welder (1kW transformer, controller, electrodes). Needs assembling.

* New packs will need balance-connector board.

Last update 2018-04-17