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 each. Donor charger bodies off ebay are about £10-13.

B6 50W charger (£11) would charge faster, but is discontinued.

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). 2 more base bodies bought (May 10th) so we have 3 now.

• 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.

• The 2 new packs will need balance-connector board.

Batts

Possible 18650 choices: Samsung 25R 2500mAh 20A Samsung 30A 3000mAh 15-30A LG HB2 1500mAh 30A £3.79 LG HB4 1500mAh 30A £4.19 LG HB6 1500mAh 30A LG HD2 2000mAh 25A LG HE4 2500mAh 20A LG HG2 3000mAh 20A £5.45 Sony VTC5A 2500mAh 25-35A £6.19 Sony VTC6 £5.45 3000mAh 15-30A £5.45

Last update 2018.05.15