How can I tell my dell precision 7510 battery is dead?

Actually you can easily tell acording to the battery charging light color.

Alternately blinking amber light and white light
    An unauthenticated or unsupported non-Dell AC adapter is attached to your laptop. Re-plug battery connector, replace battery if the issue reoccurs.

Alternately blinking amber light with steady white light
    Temporary battery failure with AC adapter present. Re-plug battery connector, replace battery if the issue reoccurs.

Constantly blinking amber light
    Fatal battery failure with AC adapter present. Fetal battery, replace the battery.

Light off
    Battery in full charge mode with AC adapter present.

White light on
    Battery in charge mode with AC adapter present. 

The above source from official manual.

dell precision 7510 battery

The brand new original dell precision 7510 battery, dell precision 7510 11.4V 7950mAh laptop batteries detail is as below:

    Voltage: 11.4V
    Capacity: 7950mAh (91Wh)
    Battery cells: 9-cell
    Chemical: Li-ion
    Battery Color: black
    Condition: new original battery
    Warranty: 9 months

The battery is in stock and available here: https://www.storebattery.co.nz/dell-precision-7510-11.4v-7950mah-laptop-battery-store-for-new-zealand-p-174361.html

How to run a dell g5 5590 flea power release?

Flea power is the residual static electricity that remains on the computer even after it has been powered off and the battery has been removed. The following procedure provides the instructions on how to conduct flea power release:

1. Turn off your computer.
2. Disconnect the power adapter from your computer
3. Press and hold the power button for 15 seconds to drain the flea power.
4. Connect the power adapter to your computer.
5. Turn on your computer

The above source from official manual.

dell g5 5590 battery

Promotion!!! 30% off for a brand new dell 1f22n 15.2V 3750mAh laptop battery, the battery specification is as below:

    Voltage: 15.2V
    Capacity: 3750mAh (60Wh)
    Battery cells: 4-cell
    Chemical: Li-ion
    Battery Color: black
    Condition: new original battery
    Warranty: 9 months

Product link: https://www.storebattery.co.nz/dell-1f22n-15.2v-3750mah-laptop-battery-store-for-new-zealand-p-255293.html

What should I do first when I get a a new Acer spin 1 sp111-32n battery pack?

Before you use a ACER battery pack for the first time, there is a conditioning
process that you should follow:

1. Connect the ACER AC adapter and fully charge the battery.
2. Turn on the computer and complete setting up the operating system.
3. Disconnect the AC adapter.
4. Operate the computer using battery power.
5. Reconnect the AC adapter and fully charge the battery again.
Follow these steps again until the battery has been charged and
discharged three times

Acer spin 1 sp111-32n battery

 Brand new acer spin 1 sp111-32n 7.7V 4670mAh laptop battery specification
    
    Price: 100 NZD free shipping
    Voltage: 7.7V
    Capacity: 4670mAh (36Wh)
    Battery cells: 2-cell
    Chemical: Li-ion
    Battery Color: black
    Condition: new original battery
    Warranty: 9 months
    Shipping time: 7-15 business days

The battery is available here: https://www.storebattery.co.nz/acer-spin-sp111-32n-7.7v-4670mah-laptop-battery-store-for-new-zealand-p-205683.html

How to Conserve Hp envy 13-ad012nc battery power?

●Select the Power saver power plan through Power Options under System and Security in Windows Control Panel.
●Turn off wireless and local area network (LAN) connections and exit modem applications when you are not using them.
●Disconnect external devices that are not plugged into an external power source, when you are not using them.
●Stop, disable, or remove any external media cards that you are not using.
●Use the screen brightness keys to adjust screen brightness as needed.
●If you leave your work, initiate Sleep or Hibernation, or shut down the computer.

The above sources from official manual.

Upgrade the envy 13-ad012nc battery, hp envy 13-ad012nc 7.7V 6962mAh laptop batteries

Price: 107 NZD (free shipping)
Voltage: 7.7V
Capacity: 6962mAh (53.61Wh)
Battery cells: 6-cell
Chemical: Li-ion
Battery Color: black
Condition: new original battery
Warranty: 9 months
Shipping time: 7-12 business days

The product link: https://www.storebattery.co.nz/hp-envy-13-ad012nc-7.7v-6962mah-laptop-battery-store-for-new-zealand-p-273078.html