I’ve talked to Pioneer4You and a couple other contacts and according to them, the charge port on this device is done properly and safe:
Q) Why that charge port again?
A) We use a 9V charge port here, all of the problems happened in v3 were solved now.
Q) Are the batteries in series or parallel?
A) The batteries are in series.
Q) Why no included charge cable?
A) Because the cost would be to high.
Q) Is it safe to use the charger?
A) It’s a safe charger.
Q) Is it a balanced charger?
A) It’s a balanced charger.
Q) Why no USB charging?
A) As the batteries are in series on the charging design, we need a 9V charger, but there is only 5V on USB port, it’s not enough good for our charging design.
Q) Why is this port being used again if it was deemed unsafe and removed from the IPV3?
A) As we have solved all of the problems on v3, we use this port again, it’s absolutely safe
Q) How many amps can you charge it at?
A) You can use a 2A charger to charge the batteries.
I’m doing a little torture testing on my own to validate this. If it passes, I’ll move ahead with the review.