Electric bike (Zip) 24V

Conundrum, Tue Apr 04 2017, 06:52AM

Hi all.

Recently acquired a "Zip" electric bike used.

Its in pretty sad shape, one of the two batteries seems to have failed so replacing them with brand new lead acids.
Also has some minor rust but it is rideable at the moment although the seat is an unfavorable shape so that needs replacing.

As these are critical to safety and the regulator on my last e-bike failed for this reason, I am going to be charging it using an external pack when needed.
Also adding reed based remotes to the two permanently mounted lights so both turn on at the same time without messing around with irritating buttons, and a few extra failsafes such as a GPS/classified tracker (see other project, can't say why) that can locate a stolen bike to within 20 feet.
Remote control for the battery pack so it can be shut off if unauthorized person using it and activates magnetic brake(s) so that the bike is basically unusable if stolen.
Battery tracking and MTTP so that if the battery gets below 55% SOC it supplements power from the regeneratively powered supercapacitor array.

Does anyone know if the old relay is likely to be salvageable, its been glitchy for a while but have here an LD-24F 14VDC 40/30A with 24VDC coil and am going to add magnetic sensors to ensure adequate contact closure without wasting power in the coil.
Probably OK to connect these in series as this provides a safety margin and can connect one side to the alarm so both have to be engaged for the bike to work.
Also have some monster reed relays here which might be suitable as they are argon filled and suitable for about 3A apiece.
Re: Electric bike (Zip) 24V
Sulaiman, Tue Apr 04 2017, 10:05AM

just in case you are not familiar with these two 'tricks' to reduce relay coil power consumption. Link2
this trick also allows lower voltage coils to be used in higher voltage systems, e.g. your 24 V bike coud use 12 V relays.
or (e.g. G5RL- type) latching relays are effectively zero coil power.
Re: Electric bike (Zip) 24V
Conundrum, Wed Apr 05 2017, 06:52AM

Thanks for the link!
Also read somewhere that for high speed use reversing the field helps.
I think this method is used for reed switches in test fixtures, even now the semiconductor switches are only approaching the low RDSon found in a reed switch from the late 1980s.