New charger: basic advice needed (newbie)

hueman · Jan 12, 2019

Hi Guys,
forgive me but i can't find all the info i would like to before i start trying to charge/discharge my H batterys.
I just received my Awesome multicharger - "EV-PEAK CQ3".
Reason i wanted this one is it can do 4 batterys at 100W at the same time and run off DC power (hence in the field offa my solar powered battery bank)! Also has a good discharge rate for faster discharging!
I also have the correct H charging cables and am almost ready to go.
I've read bits and pieces scattered through some of the posts on here but really require some definitive info before going ahead - don't wanna do any damage. Some have said the the standard 5400mA batts are actually 6300mA. Guess I'll stick to 5 at first and try 6 later when comfortable.

What i would like to know are the settings and operation.

1. Do i need to set the voltage i want them charged/discharged to and if so what voltages exactly?
2. Do I set the voltage per cell or the voltage for the entire battery to be charged to?
3. Do i need to set the current at which they charge (5400mA/6300mA for 1 C)
4. Will the charger automatically stop charging when it reraches those settings?
5. Does the cell balancing occur automatically?

I've read the manual that comes with it but am new to using these type chargers.
Hence the (possibly dumb) questions.

Any advice MUCH appreciated, keen to get going

Thanks!

DroneOn · Jan 12, 2019

Hi Hueman, this a youtube like that answers almost all of your questions. I would suggest a 1C charge rate for the TH batteries. This is a good charger !

hueman · Jan 12, 2019

DroneOn said:
Hi Hueman, this a youtube like that answers almost all of your questions. I would suggest a 1C charge rate for the TH batteries. This is a good charger !

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Thanks for the link, i think thats one i already saw when reviewing, unfortunately it doesn't really answer all my questions tho.
I'll do some more research,
Thanks again.

DoomMeister · Jan 12, 2019

Here is a good place to learn all you need to know about charging and discharging your LiPo batteries. Lithium Polymer Etiquette: a Comprehensive Guide to Working With LiPo.

So using their information the OEM battery is 5400 mAh or 5.4 Ah and at 1C charge rate gives you 5.4 A. The full charge voltage of 16.8 V (4.2V per cell) multiplied by 5.4 A equals 90.7 W, so you are well within the charge rating of 100W per channel.

Looking at the user manual for cq3 the max discharge current is 5A but that is through a 10W load. 10W divided by the rated voltage of 16.8 V gives you a max discharge rate of 0.6 A. Approximately 9 times longer to discharge than to charge.

Right now I use three 6V lantern lamps to discharge from 16.8 to 15.3 volts. It takes about an hour. Then put them on the charger for placing to storage voltage of 15.4V (3.85 V per cell).

hueman · Jan 12, 2019

DoomMeister said:
Here is a good place to learn all you need to know about charging and discharging your LiPo batteries. Lithium Polymer Etiquette: a Comprehensive Guide to Working With LiPo.

So using their information the OEM battery is 5400 mAh or 5.4 Ah and at 1C charge rate gives you 5.4 A. The full charge voltage of 16.8 V (4.2V per cell) multiplied by 5.4 A equals 90.7 W, so you are well within the charge rating of 100W per channel.

Looking at the user manual for cq3 the max discharge current is 5A but that is through a 10W load. 10W divided by the rated voltage of 16.8 V gives you a max discharge rate of 0.6 A. Approximately 9 times longer to discharge than to charge.

Right now I use three 6V lantern lamps to discharge from 16.8 to 15.3 volts. It takes about an hour. Then put them on the charger for placing to storage voltage of 15.4V (3.85 V per cell).

Brilliant, thanks! I had hoped the discharge was way faster but i guess itll have to do.

DoomMeister · Jan 12, 2019

DoomMeister said:
Here is a good place to learn all you need to know about charging and discharging your LiPo batteries. Lithium Polymer Etiquette: a Comprehensive Guide to Working With LiPo.

So using their information the OEM battery is 5400 mAh or 5.4 Ah and at 1C charge rate gives you 5.4 A. The full charge voltage of 16.8 V (4.2V per cell) multiplied by 5.4 A equals 90.7 W, so you are well within the charge rating of 100W per channel.

Looking at the user manual for cq3 the max discharge current is 5A but that is through a 10W load. 10W divided by the rated voltage of 16.8 V gives you a max discharge rate of 0.6 A. Approximately 9 times longer to discharge than to charge.

Right now I use three 6V lantern lamps to discharge from 16.8 to 15.3 volts. It takes about an hour. Then put them on the charger for placing to storage voltage of 15.4V (3.85 V per cell).

BTW those lamps are connected in series with each other. Later on I will get three more and connect them in series then connect the two strings of three in parallel to be able to discharge faster. The OEM batteries are 8C batteries from all I have been able to discover for discharge rating so 5.4A times 8C or 43.2 A. At full discharge rate of 8C you would get about 7.5 minutes until the battery reaches max discharge voltage of 12 V (actually about 4.5 to 5 minutes until low voltage warning on the ST-16.

hueman · Jan 13, 2019

DoomMeister said:
BTW those lamps are connected in series with each other. Later on I will get three more and connect them in series then connect the two strings of three in parallel to be able to discharge faster. The OEM batteries are 8C batteries from all I have been able to discover for discharge rating so 5.4A times 8C or 43.2 A. At full discharge rate of 8C you would get about 7.5 minutes until the battery reaches max discharge voltage of 12 V (actually about 4.5 to 5 minutes until low voltage warning on the ST-16.

Yea but are you using a voltmeter to check when each batt is down to the correct level then disconnecting them? Awfully manual way to do it, then again, if its only taking 5 minute s i guess its great! But fiddly. Would be great to put together a device that senses its levels and shuts down automatically, perhaps using an Arduino?

DoomMeister · Jan 13, 2019

I check the voltage through the balance leads. With eventually make a wire harness to hook the voltmeter to the balance leads. Not good to leave LiPo’s unattended anyway. I don’t sit right with them, stay with sight of them just in case.

hueman · Jan 13, 2019

DoomMeister said:
I check the voltage through the balance leads. With eventually make a wire harness to hook the voltmeter to the balance leads. Not good to leave LiPo’s unattended anyway. I don’t sit right with them, stay with sight of them just in case.

You were absolutely correct with your discharge calculations!
Just tested a full battery to storage level discharge - screen showing 0.6A and its taken well over 2 hours!
Shame! I'm gonna have to rig something up along the same lines as you have.
It would be a great invention to make a 5 minute automatic shutoff storage discharge device!!! Wish i was a bit more electrically charged

DoomMeister · Jan 13, 2019

I think I’m going to do some tinkering in that department. I would rather keep the discharge rate down to about 3C to reduce heat build up in the battery. Too fast and it lowers the lifespan of the LiPo.