Frankly, I was a bit concerned that an aftermarket charger might trash my expensive
M2P batteries. After playing with this, I think it's both safe and a lot better than the stock charger. Not perfect, but certainly a good deal ($55). My review below.
https://www.amazon.com/Hanatora-Bat...07Y9V4GTR/ref=cm_cr_arp_d_product_top?ie=UTF8
Note: Referring to cell balance, I'm sure it's not the discrete balance (as might be achieved with a separate plug with leads to each cell), rather this is a timed, low current finish charge of about 20 minutes, during which time or after, the battery is ready for use. The low current prevents overheating and damage to the already full cells - - at least that's the basic premise.
Review:
My background is in electronics, this review will be "gently" technical. This is more than just a great charger, it has 3 important and discreet modes:
1) Full charge with cell balance
2) Storage charge with cell balance
3) Full discharge to zero.
1) Charging: Plug in up to 4 batteries and they will all charge simultaneously. Note that when charging 4 batteries, station 4 will initially not charge at a 2 to 3 amp rate as do stations 1 - 3. This is due to max power considerations. As soon as the 1-3 receive a significant charge, station 4 will start to catch up. At about 99% charge, the finish charge will be low current to balance the cells (the battery can be removed at this point if needed.
2) you can plug in your discharged or charged batteries and depending on their individual state, they will be discharged down, or charged up, to 15.4 to 15.8 volts for long term storage. Storing at this charge level prolongs battery life and should be considered if you won't be flying your drone for a few days or more. Storing lithium batteries fully charged stressed them, so this is a useful feature. This is also why
Mavic 2 batteries (and probably others) are programmed to initiate a slow self discharge when stored in a charged condition for a set number of days (I believe the default is 10 days, I changed mine to 5 days). But really, it's better not to store them fully charged for any appreciable length of time if it can be avoided - - overnight for flying next morning, no problem. But if flying late morning, then this charger makes it quick and easy to charge 'em all while having breakfast!
3) Another feature is discharge mode . The will discharge a fully or partially charged battery down to zero (0%) which is recommended after every 20 or so charge-discharge cycles for maximum battery longevity.
Note that when using the car charging cord, the vehicle's engine will need to be running before plugging in the charger. Otherwise, due to the high current demand, the charger's input voltage will be too low and you will get an error indication on the display..
Noise: Not objectionably at all. Both the AC power adapter and the charging cradle have small muffin style cooling fans to dissipate heat, a necessary design feature when charging with this much power. BTW, no smell noted.
All in all, a reasonably priced and far more convenient upgrade compared to the DJI provided charger.
Minor cons (communicated to mfg): Add an on/off rocker switch on AC power adapter so one does not have to unplug cord between uses.
Add a bit more length to the DC (car charger) cord. Note that due to fairly high current demand, wiring loss (voltage drop across wiring) can be an issue - that's the reason they kept the cord fairly short. As a result, on some vehicles, this leaves no convenient place or rest the charger with batteries - especially when driving (and who wants to sit parked with engine running for an hour to charge batteries?). They could increase wire thickness and add a foot or so to the length with no net loss.
I'm very happy with this charger.
