Howcome battery charger runs at 992W?

F

Flyback

Well-Known Member
Hi, This is the TB65 battery for DJI Matrice 350 RTK drone.

DJI Matrice 350RTK drone

TB65 battery:

DJI TB65 Intelligent Flight Battery CP.EN.00000457.01 | Drones Direct

Buy DJI TB65 Intelligent Flight Battery CP.EN.00000457.01 from Drones Direct - the UK's leading online drones retailer, we offer expert advice
www.dronesdirect.co.uk
It is 45V, 6Ah
(this seems an awful small battery for a 6.5kG drone?)

The charger (BS65) for it is this...

BS65 charger:

BS65 Intelligent Battery Station for TB65 and WB37 Battery - DJI Matri

The battery station is a one-stop solution for battery charging, storage, and transport. The new Storage Mode and Ready-to-Fly Mode improve charging efficiency and extend the battery life. The new 360°-movement wheels facilitate more convenient transportation and transitions. The battery station...
dji-retail.co.uk
..This charger claims to be able to charge 2 x TB65 batteries and 1 x WB37 batteries simultaneously
(WB37 is just 8V X 5Ah)

WB37 battery:

DJI WB37 Battery for RC Plus / DJI Monitor / DJI Transmission

This 2S 4920mAh battery has excellent discharge performance at low temperatures and charges quickly. Overview This 2S 4920mAh battery has excellent discharge performance at low temperatures and charges quickly. In The Box WB37 Intelligent Battery × 1 Specifications Capacity: 4920 mAh Voltage...
dji-retail.co.uk

The BS65 charge station says it runs at 992 from 230VAC.

But hang on....batteries should be charged at 1C and no more..therefore, the power draw from charging the 2xTB65 and 1XWB37 batteries should be no more than 580W, so howcome it is delivering 992W?
 
Sort by date Sort by votes
I think you are conflating different units and drawing erroneous conclusions. Show your work and maybe we can spot the problem. In particular power is not equal to voltage times ampere-hours.
 
Upvote 0 Downvote
Papabravo said:
I think you are conflating different units and drawing erroneous conclusions. Show your work and maybe we can spot the problem. In particular power is not equal to voltage times ampere-hours.
Click to expand...
He seems to have multiplied nominal battery voltage by capacity (1C charging). Doing this would give you 580W max for instantaneous power: 6A * 45v * 2 (two TB65s) + 5A * 8v. It does seem correct to me. To get the max possible instantaneous power draw from the charger though you would also have to add 65W for the typc c port which would yield a max power draw of 645W.

The 992W rating is probably the theoretical max continuous output power of the charger and not the power it requires from mains at all times, but even then I don't see why it would need to be so high? Also when supplied with 100-120VAC instead of 220-240VAC the max stated output power drops to 750W which sounds more reasonable.
 
Upvote 0 Downvote
You must log in or register to reply here.

Similar threads

C
  • Locked
  • Question
Battery Charger Circuit
Replies
10
Views
3K
rjenkinsgb
S
  • Question
nicd charger for li-ion
Replies
11
Views
867
MrAl
M
D
Ctek xs7000 charger
Replies
2
Views
1K
doggone1
D
A
  • Question
question battery ni-mh
Replies
3
Views
658
danadak
F
  • Question
Can I charge my Pocket 3 with this charger?
Replies
3
Views
328
rjenkinsgb
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…