70mai Dash Cam Battery Pack (7500 mAh) - Test / Review - RCG

[rcg530]

70mai sent me a test/review sample of their new 7500 mAh (96 Wh) Lithium Iron Phosphate (LiFePO4) battery pack. I've started testing this battery pack (limited tests so far).

Specifications listed on the box:

• Model: BL96NNX
• Nominal Voltage: 12.8V
• Rated Capacity: 7500 mAh
• Rated Energy: 96 wh
• Nominal Capacity: 7600 mAh
• Limited Charging Voltage: 14.6V
• DC Output (XT30): 11.2 - 14.2V 2A Max
• Type-C Output: 5V 2.4A Max
• DC Input: 11.2-30V 11A Max
• Charging Temperature: 0°C ~ 45°C (32°F ~ 113°F)
• Discharge Temperature: -10°C ~ 60°C (14°F ~ 140°F)

Additional Specifications In User Manual:

• Battery Type: LiFePO4
• Storage Temperature: -10°C ~ 60°C (14°F ~ 140°F)
• Max Cigarette Lighter Power Adapter Charging Amps: 7 Amps
  • Charging Time: 90 minutes
  • The CLA charging cable is not included in the box (optional accessory)
• Max Fuse Box Charging Amps: 11 Amps
  • Charging Time: 60 minutes
• After 2000 complete charge/discharge cycles
  • Battery retains 70% of its original capacity

Battery Pack Size

• 22 CM x 12 CM x 3.5 CM (8.67" x 4.72" x 1.38")

What's In The Box

• Battery Pack
• Fuse box charging cable
• Parking surveillance cable adapter
  • 3-wire cable that is to be spliced with dash camera's hardwire cable/adapter/kit
  • Each wire also has a 1-wire lever connector nut [no soldering required]
• Type-C to Type-C output power cable
• Four fuse taps
• Four 20A fuses [one for each fuse tap type]
• Cable ties
  • The box I received only contained one Velcro cable tie
• Two Velcro tape strips
  • Can be used to secure the battery pack to the installation location
• User manual

Initial Thoughts

• Charging Power Choice
  • Hardwire vs Cigarette Lighter Adapter (CLA) - Purchase Time Decision
    • The battery pack comes with one charging cable based on your purchased time decision.
  • Hardwire Charging Cable
    • Stated charging time from 0% to 100% is approx 60 minutes
    • The charging cable contains 16 AWG wires.
      • This seems a bit undersized for the number of max charging amps (11). With the ambient air temperature during my charging test being 83F, the charging cable reached a max of just under 100F during the high amp draw portion of the charge cycle.
      • 
    • The installer is expected to source the constant (VCC) power supplied to the battery pack from a fuse tap
    • Four different fuse tap types are provided in the box - each having a 20 Amp fuse installed in the accessory device (top) fuse slot
      • The battery pack is rated at a max of 11 Amps, so the 20 Amp fuse seems too high of an amp rating (15 amp would be sufficient)
      • Adding a 11 amp load to a pre-existing fuse box circuit may be overtaxing the wiring providing power to the fuse box fuse socket if the pre-existing item(s) powered by that fuse box fuse socket are consuming a vast majority of the current capacity of the circuit.
    • The installer is told to wrap the accessory power sense wire (ACC) around a leg of the fuse in the fuse box (major fail!)
      • You never wrap a wire around a fuse leg since it my expand the contacts in the fuse box fuse socket (major fail!).
      • The installer may not select the side of the fuse box fuse socket that will be protected by the fuse (major fail!).
      • There should be another fuse tap provided in the box for the ACC wire to be properly installed into the fuse box.
  • CLA charging cable
    • Stated charging time from 0% to 100% is approx 90 minutes
    • Vehicle's Cigarette lighter (power) port must provide switched power
      • The vehicle's power port must turn off the power to this port when the vehicle's ignition is turned off.
  • Switching from "Fuse Box" charging to "CLA Charging"
    • There is a process identified on page 5 of the user manual that you must perform to "unlock" the battery pack so that the battery pack can be successfully charged using the CLA charging cable.
• Multiple references to XT30 connectors when the battery pack uses MR30 connectors
  • There are multiple places in the product documentation that states the battery pack has XT30 connectors.
  • It actually has MR30 connectors.
• First Time Charging Test - Fuse box charging cable option
  • I used a DC power supply set to 14.2V with a maximum of 10.2 A (max for the DC power supply)
  • The evening before the test, the battery pack had been fully discharged using a DROK USB load tester
  • Maximum Amp Draw
    • Occurred at 49 mins 26 seconds [click on picture]
    • Output
      • VCC = 14.20V
      • ACC = 14.07V
    • Charging (Input)
      • Amps = 8.742 Amps
    • 
  • Charging Progress
    • Start
      • Fully discharged battery pack
      • Output
        • VCC = 0.0V
        • ACC = 1.7 mV
      • 
    • First power sent to dash camera
      • At 2.6 seconds, the output (dash camera) VCC and ACC power started receiving power
      • Output
        • VCC = 13.78V
        • ACC = 13.87V
      • Charging (Input)
        • Amps = 2 mA
      • 
    • Approx 20 second delay before charging starts
      • At 22.2 seconds, the battery pack starts drawing charging power from the DC power supply
      • Output
        • VCC = 12.02V
        • ACC = 11.93V
      • Charging (Input)
        • Amps = 3.258 Amps
        • Amps ramp up to 7.252 Amps within 5 additional seconds
      • 
    • 25% Charge Level
      • At 15 minutes 9 seconds, the battery pack reached a 25% charge level
      • Output
        • VCC = 13.85V
        • ACC = 13.73V
      • Charging (Input)
        • Amps = 8.555 Amps
      • 
    • 50% Charge Level
      • At 29 minutes 23 seconds, the battery pack reached a 50% charge level
      • Output
        • VCC = 13.92V
        • ACC = 13.80V
      • Charging (Input)
        • Amps = 8.588 Amps
      • 
    • 75% Charge Level
      • At 43 minutes 34 seconds, the battery pack reached a 75% charge level
      • Output
        • VCC = 14.05V
        • ACC = 13.93V
      • Charging (Input)
        • Amps = 8.669 Amps
      • 
    • 100% Charge Level
      • At 43 minutes 34 seconds, the battery pack reached a 75% charge level
      • Output
        • VCC = 13.86V
        • ACC = 13.89V
      • Charging (Input)
        • Amps = 6 mA
      • 

 

[kamkar]

Yes the thin cable also worried me a bit, i understand a acquaintance of mine might have some of the plugs that the 70mai power pack use, if that is the case and i can get one i think i will make a new charge wire.
It would not be a big problem for me with the skills / and tools i have.

 

[Panzer Platform]

The installer is told to wrap the accessory power sense wire (ACC) around a leg of the fuse in the fuse box (major fail!)

• You never wrap a wire around a fuse leg since it my expand the contacts in the fuse box fuse socket (major fail!).
• The installer may not select the side of the fuse box fuse socket that will be protected by the fuse (major fail!).
• There should be another fuse tap provided in the box for the ACC wire to be properly installed into the fuse box.

Yikes!

Multiple references to XT30 connectors when the battery pack uses MR30 connectors

• There are multiple places in the product documentation that states the battery pack has XT30 connectors.
• It actually has MR30 connectors.

Yes, these MR30 connectors are a pain in the @ss.
They are so small there are very difficult to unplug.
Every time I need to unplug the input / output I think I’m going to rip the tiny 16AWG wire out of the MR30 conector.
I told the 70mai rep in January these MR30 connectors were a mistake, and to use the much larger XT60 connectors found on the EGEN packs.
The XT60 also allow 12AWG wire.
The MR30 connectors only allow 16AWG wire.
The 70mai rep told me the first gen pack will use MR30 connector to keep cost down.
What I would like is for all battery packs to ditch any connector, and use bare wire terminal like car audio amplifiers.
This way the user can supply their own 12AWG 100% OFC pure copper power & ground wire, instead of the included (cheap & too thin) 16AWG CCA copper clad aluminum.
See attached photos.

100% Charge Level

I do like how the pack can fully 100% charge in the claimed 60 minutes with hardwire configuration.
I remember the PowerCell 8, and B-130X taking much longer than the claimed hardwire charge time.
Let me go look at my PC8 testing thread to confirm.
-
I have attached two photos of the 70mai's LiFePO4 cells.

 

[Panzer Platform]

Yes the thin cable also worried me a bit, i understand a acquaintance of mine might have some of the plugs that the 70mai power pack use, if that is the case and i can get one i think i will make a new charge wire.
It would not be a big problem for me with the skills / and tools i have.

Even if you get a hold of some MR30 connectors the internal lugs only accept 16AWG wire.
So you will have to trim down 12AWG wire a bit, and stuff them through the clip piece before, and after soldering the wires in place.
This is why I have not purchased MR30 connectors to make my own 12AWG charging cables like I did for the PowerCell 8, and B-130X.

 

[GPak]

The MR30 is probably OK for powering the dash cam, but for charging they should have gone with the XT60I connector, using the middle pin for the yellow trigger.
I guess the limiting factor is the small case size.
I use the MR60 to charge my DIY batteries, it is easy to work with, but not available with flanges for mounting on a case, so I have to route power wires through o-ring/grommet.

 

[Panzer Platform]

The MR30 is probably OK for powering the dash cam, but for charging they should have gone with the XT60I connector, using the middle pin for the yellow trigger.

Yes.
The B-130X uses the XT60I-F connector for the Cigarette Lighter Charge Cable.
It uses the 3rd pin to let the pack know it’s being charged with the CLA cable, and not the hardwire cable, and drops the charging current from 9 Amps to 5 Amps.
See attached photo stolen from RCG530’s thread.

 

[frontier]

60 minute charge time is pretty impressive.