Page 1 of 1

RMP 400 with Unified Enclosure - Charging and Aux Power

Posted: Fri Aug 22, 2014 11:51 am
by ChrisC
RMP 400 – Battery and Charger Configuration Overview:

There are five batteries attached to the underside of the RMP 440. Inside the enclosure are three AC-DC chargers, each with two channels.

The fore and aft chargers are identical and have ON/OFF switches as they were originally designed for Segway’s standalone off-board charger accessory. The switches on these chargers should always remain in the ON position. These chargers are responsible for charging the four propulsion batteries attached to the two powerbases.

The center charger is a different form factor than the other two and is responsible for charging the Aux battery. There is no ON/OFF switch for this power supply module.

All three chargers are energized when the RMP is connected to mains power through the power cord.

Also within the enclosure is a DC-DC converter (blue anodized brick) with 12V output. This 12V power is connected to the charger circuits on the two Deuce UI logic boards for charging their discrete 2-cell battery packs. The 2-cell battery packs extend the runtime of the platform beyond the capability of the Aux battery since the Aux battery is also intended to be used for powering customer equipment. The ON/OFF switch on the 12V DC-DC converter brick (inside the enclosure) should remain in the ON position at all times.

Important Note: There is a low voltage alarm which sounds when the Aux battery needs to be charged. There is no discharge protection circuit for the Aux battery and allowing the Aux battery to discharge lower than 55V will result in permanent damage to the battery. To disconnect the load on the Aux battery, switch OFF the rocker on the enclosure bulkhead.

RMP400 Charging Protocol:

To recharge the RMP 400’s five main batteries, connect the power cord between a properly grounded mains outlet and the circular bulkhead charge port connector. Battery charging status indication is not provided on the exterior of the RMP 400. If the enclosure lid is removed, the LEDs on the charger power supplies can be seen. These LEDs indicate the charging status per the following charge stage descriptions:

Initial Test - Batteries immediately proceed to “Fast Charge.”
Fast Charge - Solid green LEDs. The majority of charging takes place during this stage.
Cell Balancing - Green pulse. Slows down over time. Lasts a few minutes to several hours, depending on how much balancing the cells require.
Fully Charged - LEDs are unlit for approximately 5 minutes.
Battery Maintenance - Several fast green pulses every few seconds.

Alternatively, and if the enclosure lid is installed, a Watt meter can be used inline with the AC power cord to identify the status at different stages of the charge cycle.

Follow these steps to monitor the charge cycle using an inline Watt meter:

1. Attach the Watt meter in between the RMP charge cord and the 110V wall outlet.
2. Set the display mode on the meter so that it is monitoring Watts.
- During fast charge of depleted batteries, the meter will read ~280W.
- As the charge cycle progresses and as the separate battery packs reaches full charge, the Watt value will begin to decrease incrementally.
- When the display’s Watt value begins to fluctuate between 0 and ~20W, the platform is fully charged. This fluctuation indicates the charge cycle is complete and the batteries are in maintenance charge mode.

The RMP 400 should be recharged after use and is safe to remain “on charge” when not in use. If left “on charge” for extended periods of time, Segway recommends that you reset the chargers every 30-60 days by disconnecting and reconnecting the power cord.
Caution! Failure to charge the batteries could result in damage to the batteries. Left unplugged, the batteries could fully discharge over time, causing permanent damage.

Aux Power Operation:
The rocker switch on the RMP 400 electronics enclosure bulkhead is the ON/OFF switch for Aux battery. When switched ON the 12V DC-DC converter powers the Deuce board 2-cell battery charger circuit and 12V user power. The Aux power rocker switch should in the ON position whenever the RMP 400 is in use.
The Aux power rocker switch should be switched OFF:
• Whenever the RMP 400 is powered off and not in use.
• During charging of the main batteries.
• As soon as possible when the low voltage alarm sounds.