The audience for this quick project is the large majority of Golf Cart owners that own a OEM charger without float mode.
I decided to add a timer (really remote On/Off) capability to my Powerdrive 3 charger.
The typical method would be to add a 120v coil relay to the charger and run the "sense" wire through the Normally Open connections of the relay.
That way the "sense" wire gets disconnected when the AC power is removed from the charger.
I don't like that method for several reasons:
New method I used:
The installation is pretty simple:
If the timer relay power cord is unplugged, the charger works as before.
I used an old monitor power cord, the PG7 cable gland works well for any computer/monitor/printer/etc power cords.
I also had a "fan relay" that I used, but here is a link to a good one to use (120v AC coil).
I am using a WiFi timer/Remote ON/OFF device, but there are lots of options out there since You only need a light duty timer.
If You cart is parked somewhere that You only use on the weekends, You can use a weekly timer to have the pack charged right before You get there so it is ready to go.
The timer only needs to stay ON for 1 minute in order to start a new charging cycle.
I left the timer relay power cord short since I would be mounting my WiFi timer where I get better reception and run an extension cord to the charger anyway.
I decided to add a timer (really remote On/Off) capability to my Powerdrive 3 charger.
The typical method would be to add a 120v coil relay to the charger and run the "sense" wire through the Normally Open connections of the relay.
That way the "sense" wire gets disconnected when the AC power is removed from the charger.
I don't like that method for several reasons:
1) The Relay stays ON the entire time the charger is plugged in to AC power.
2) It requires a Heavy Duty Timer to provide the power needed for the charger when it is running.
3) Power failures or brown-outs could lead to another charging cycle being triggered.
4) The Timer needs to keep the Charger Powered the entire time is plugged to the cart.
5) Most timers load control is done by a PC board soldered relay and are not very robust for continuous duty.
6) A timer failure means no more charging.
New method I used:
1) The Relay stays OFF during normal use.
2) You only need a light duty timer since it is not powering the charger.
3) Power failures or brown-outs do not start another charging cycle.
4) The timer keeps the relay OFF except for a 1 minute run time to trigger another charging cycle.
5) The relay draws less than 0.1 amp for the 1 minute it needs to run.
6) A timer failure will not prevent the regular charging cycle from operating.
The installation is pretty simple:
The relay coil is directly wired to the power cord (no fly-back diode is needed since it is AC).
The "sense" wire inside the charger gets wired trough the relay Normally Closed contacts.
If the timer relay power cord is unplugged, the charger works as before.
I used an old monitor power cord, the PG7 cable gland works well for any computer/monitor/printer/etc power cords.
I also had a "fan relay" that I used, but here is a link to a good one to use (120v AC coil).
http://www.mouser.com/ProductDetail/...bgw%252bfFI%3d
I am using a WiFi timer/Remote ON/OFF device, but there are lots of options out there since You only need a light duty timer.
If You cart is parked somewhere that You only use on the weekends, You can use a weekly timer to have the pack charged right before You get there so it is ready to go.
The timer only needs to stay ON for 1 minute in order to start a new charging cycle.
I left the timer relay power cord short since I would be mounting my WiFi timer where I get better reception and run an extension cord to the charger anyway.