PL8 Owners & users advice

[Davy Crockett]

Hi all
help and advice from PL8 users required please
my flying is taking its place at work, I'm a land surveyor and we have been using a commercial grade UAV to survey large areas of land and produce 3d terrain models from the captured data... With great success
the UAV uses 14000mah 4s lipos and we have 2 5amp chargers and 5 lipos (1 per flight)
Question is what do I need to charge multiple lipos with the PL8... I'm not mega clued up on amps and volts and watts!
Any help gratefully received

[gazmk2]

Just get the powerlab 8 with the mpa board. You can stick all 5 lipos on at 60 amps total ( that's the powerlabs max current) and they'll all be done in about an hour.

The mpa board has fused main outputs and thermal trips on all the balance connectors. You'll need a fairly manly power supply, I'd highly recommend a coolice 2500w 24v psu.

[waveydavey]

Here you go

Understanding wattage in relationship to charging - TJinTech

Digest that little lot and you'll be on it

[gazmk2]

I've always just used the power triangle. P=I x V, that gives a you a good idea as to what your charger will handle.

[Grumpy]

Just get the powerlab 8 with the mpa board. You can stick all 5 lipos on at 60 amps total ( that's the powerlabs max current) and they'll all be done in about an hour.

The mpa board has fused main outputs and thermal trips on all the balance connectors. You'll need a fairly manly power supply, I'd highly recommend a coolice 2500w 24v psu.

FWIW the PL8 maximum current output current is 40A not 60A.
A 24V 2400W supply would do the job quite well but it's rather overkill on the watts. If the OP only ever wants to charge 4s packs then a 24V 1000W PSU would be more than ample.
The PSU ideally needs to be at over 26V though if you want to fully max out the charger. 24V is just slightly too low to get the absolute maximum power (this would only ever be an issue if charging 8s packs).

[GIXERMAN]

Continuous max output power: 612W @ +12VDC input, 1344W @ +26.35VDC

[Grumpy]

Continuous max output power: 612W @ +12VDC input, 1344W @ +26.35VDC

Which is why you need over 26V input to max the charger out.

The output is also limited on current to 40A, so you can only achieve the 1344W rating if charging an 8s battery (8 x 4.2V x 40A = 1344W). If charging 4s batteries the max output is limited to 672W because you hit the 40A current limit.

[gazmk2]

FWIW the PL8 maximum current output current is 40A not 60A.
A 24V 2400W supply would do the job quite well but it's rather overkill on the watts. If the OP only ever wants to charge 4s packs then a 24V 1000W PSU would be more than ample.
The PSU ideally needs to be at over 26V though if you want to fully max out the charger. 24V is just slightly too low to get the absolute maximum power (this would only ever be an issue if charging 8s packs).

Mine has a maximum of 60a? Although I have just remembered that the MPA board has a max total current handling of 40a.

Still a hell of a lot quicker than a couple of 5a chargers though!

[Grumpy]

Mine has a maximum of 60a? Although I have just remembered that the MPA board has a max total current handling of 40a.

Well it must be a special 'one-off' unit because the official Revolectrix spec says 40A output charge current :

Output battery charge current: Adjustable range 10mA to 40A, limited by 60A input current*

Input current from the PSU is 60A max but input is not the same as output.

If you want more than 40A then I think the only chargers that will do it is one of the iCharger Duo range when configured in Synchronous mode. For instance my iCharger 4010 will do 70A in synchronous mode. I never use it that way, two separate 40A outputs is more convenient for most purposes.

[coolice]

Hey buddy.

Revolectrix have a great selection of online calculators on the Web site that allow you to input your battery and power supply specs to see what charge rate (c) you can achieve with your setup.

You wouldn't go wrong with either a PL6 or PL8 for what you're looking to achieve.
The recommended 26.xx input voltage has never been a problem for many using only 25 volts, so I wouldn't be overly concerned in trying to achieve it.

As stated the output amps are limited to 40amps so you'll most likely hit this before anything else with multiple high capacity batteries.
The PL8 DUO can take greater input voltages, 48 volts for example, so would work more efficiently when higher pack voltages are used. However looking at what you need to charge, you'd never run out of power from a PL8 and be charged (6 packs on an MPA board) ready to go within an hour or less.

On the power supply front, there is always that thought that's it's best to not be using any power supply close to its limits. So going for a more powerful option straight away sometimes makes better sense. Also you may in time grab a second PL ;-)

Ian

[gazmk2]

Well it must be a special 'one-off' unit because the official Revolectrix spec says 40A output charge current :



Input current from the PSU is 60A max but input is not the same as output.

If you want more than 40A then I think the only chargers that will do it is one of the iCharger Duo range when configured in Synchronous mode. For instance my iCharger 4010 will do 70A in synchronous mode. I never use it that way, two separate 40A outputs is more convenient for most purposes.

That's probably where i've seen 60a then!

[Davy Crockett]

Thanks everyone for the advice, it is of great help

Ian, I think someone will be in touch about a PSU and I'll PM you his details