New Taranis Owner - Battery Charger Q

DarrenG · Post by **DarrenG** » Thu Sep 05, 2013 5:49 pm

Finally I'm the proud owner of a Taranis. Coming from the 9XR I'm already loving the quality feel, and having flashed the 9XR with openTx, the interface is familiar at least.

But I have one question which I can't see answered in the manual. Using the bundled battery and the 12v charger, should the green LED on the rear of the Taranis illuminate when the charger is connected? It's not at present.

RGN01 · Post by **RGN01** » Thu Sep 05, 2013 5:57 pm

Darren, I received mine yesterday so I can only speak for mine - the green LED illuminates when it is charging but goes out when the battery is charged.

Hope that helps.

Richard

DarrenG · Post by **DarrenG** » Thu Sep 05, 2013 6:09 pm

Thanks Richard, I should have checked before but have just put a multimeter on the wall wart charger and it has no output at all.

I don't have any 12v 0.5a chargers knocking about so will have to contact T9 and get it replaced

RGN01 · Post by **RGN01** » Thu Sep 05, 2013 6:20 pm

Darren, I understand that it is simply a 12V supply and that all the charge circuitry s inside the TX. There is a thread on here somewhere that spells out the problems if a smart charger is used on the DC plug - don't do it!

Can you charge the battery externally with another charger?

Richard

DarrenG · Post by **DarrenG** » Thu Sep 05, 2013 6:25 pm

I've found a cable that will provide 12v from the cigarette lighter output on the lead acid battery pack I have which drives my telescope. That seems to be working OK and the Green LED is lit. I;d read the warnings not to use intelligent chargers and see that 13.5v is the max you should use a charge voltage.

Post by **ShowMaster** » Thu Sep 05, 2013 8:53 pm

Maybe just add 1 or 2 1n4001 diodes In series with the charge cable.
This should work when 12 or 14.2 v is used and not stop the charging.
At least 1 diode.

Post by **MikeB** » Thu Sep 05, 2013 9:17 pm

You might like to read this post/thread:
http://openrcforums.com/forum/viewtopic ... =30#p58532

Mike.

GeoffSleath · Post by **GeoffSleath** » Thu Sep 05, 2013 9:46 pm

From my own somewhat fraught experience I would suggest only charging the battery separately from the transmitter. I've always been a bit anal about battery operated equipment and I like to know how much energy I've stored when I recharge a battery. It isn't possible using the supplied charger and using a better charger through the charge socket is potentially fatal (see the topic referred to by MikeB, above and be warned).

In any case if you choose to use a LiFe or LiPo instead of the supplied NiMh one that's your only option.

Geoff

Post by **MikeB** » Thu Sep 05, 2013 10:19 pm

If you don't mind voiding your warranty, I showed in the thread mentioned above about shorting out the on board charge circuit, then using your external charger!!!

Mike.

Post by **ShowMaster** » Thu Sep 05, 2013 10:37 pm

So your production unit findings "I think we should limit the input voltage to 13 volts for a flat battery, and 14 volts for a battery approaching fully charged." has come to a conclusion that 12v DC is the best design center for the internal charge to properly cut off and not overheat Mike?
At home I would use the supplied power supply that I'm assuming is 12v and not higher or lower but I should measure it under load.
Driving and topping off or adding some charge for a few hours flying ontime would be done it was low. I actually carry a 12A 12V gel battery in a small custom tip proof box in my car that I use instead of the 14v car system. I could also charge the battery externally with my smart charger on either battery system.

Enough about my setup. What do we recommend should be the best way for those wanting to use the internal charger on their car battery and charging system parked or driving?
I doubt many will charge this way driving for 6 or more hours but they may if parked.
Then there's the wall wart supply that may or may not be included

Is it really just 12v.
From your measurements it seems it should be no lower that 12v or higher than 13v under load to be effective at not over charging and still charge at a rate of over 250ma but not over 400?
My math may be fuzzy so it's ok to educate me more on your findings. I'm sure many will just plug in something that says 12v and not worry about it all.

Post by **MikeB** » Thu Sep 05, 2013 10:41 pm

I measured my supplied charger as 12.05 volts off load.

Mike.

GeoffSleath · Post by **GeoffSleath** » Thu Sep 05, 2013 11:25 pm

MikeB wrote:I measured my supplied charger as 12.05 volts off load.

Mike.

Yes, but is that really a smooth DC? I bet it's as rough as a badger's backside with 100Hz ripple

So who knows what your meter is reading? If I measured with my old AVO 8 moving coil meter on DC it'd probably be different from the reading on the digital multimeter I usually use.

Be interesting to know the voltage when it's connected to the internal charge circuit.

Geoff

Post by **ShowMaster** » Thu Sep 05, 2013 11:39 pm

Ok, I'm going to brave the 100+ deg temp in my lab (garage) and make up some DC barrel m/fm adapters as well as a set to go into the actual Nimh battery leads to help us out with more info. Fortunately I've got my personal air conditioner so I'll survive the heat.
I'll be able to measure it all.

Post by **ShowMaster** » Fri Sep 06, 2013 7:17 am

I lied, it was way to hot. I drank the beer instead.

Post by **jhsa** » Fri Sep 06, 2013 12:32 pm

Good..

Post by **ShowMaster** » Fri Sep 06, 2013 8:23 pm

Ok here's what I measured with the HK 2400ma and original Taranis 800ma pack. Both are 6 cell packs. Both packs were charged a week ago but I didn't measure the battery voltage, just charging.
I monitored the ps voltage into the Taranis charge jack and the current going into the pack by having my meter is series with the packs +lead.
Input 11.5 (min voltage for charging.)
Charging 200ma.
12v input 270-280ma charging.
13v input 380ma
13.5 input 380ma
No change from 13 to 13.5.

Taranis on current draw no audio no bl 105ma
On with BL no audio 116ma
On with BL and audio announce 120-125ma.
I used a digital meter so it may not have followed the voice peaks.

Clivew · Post by **Clivew** » Sat Oct 26, 2013 12:05 am

Ok, I'm being lazy here

Did anyone sort out what needs to be done to mod the charging circuit so that
it will fully charge a 2000mah nimh battery with the supplied charger?
Seems to me it times out before it's charged

Thanks,

Clive

Post by **ShowMaster** » Sat Oct 26, 2013 4:14 am

No news on a circuit mod yet.
No schematics to look it up on either.
In theory if it's setup to charge the 800 Ma pack and the average is 250-300ma current. The timer may be 3 hours. That means a replug every 3 hours for a fully discharged 2400 Ma pack. From what I've seen, the new Frsky pack is 2000ma. If that's the case the new timer may still timeout before a 2400ma pack will be fully charged?
I added a servo type M/FM connector into my 2400Ma battery lead so I can externally charge the battery without wearing out the Taranis tx connector.
Personally I use my smart charger to fully charge my 2400Ma LSD pack and then plug in the normal charger when I've used it a lot to keep it topped off or plug it into a 3C lipo battery on my drive to the field. Easy to go and I'm always ready to go.
I'm sure the required timer mod will be posted at some point and I'll make the change.

Post by **MikeB** » Sat Oct 26, 2013 10:05 am

The charge control device is a BQ2002F.
The charge current is nominally 400mA, but as the battery approaches full charge, its voltage gets too close to the 12V charger supply and the current reduces.
The BQ2002F looks to be set to 100 minutes timeout, but does have delta peak detection as well.

This actually doesn't look correct. The charge current is C/2 (800mAH/400mA), so the timer should be set to 160 minutes.

SO, for any battery, it looks like the charge method is:
plug in and start charging
If the charge LED goes off after around 100 minutes, unplug and plug in again to resume charging.
When the LED goes off well before 100 minutes for last plugging ijn, the battery is charged.

Mike.

Post by **ShowMaster** » Sat Oct 26, 2013 2:49 pm

Thanks Mile.
I fly for maybe 2 hours on time one day every week, my new pack is a 2400ma LSD one. Thinking that if I just plug in 12v once a week my pack will always be ready to go even if I miss a week. Because I have the original 800ma pack stored in my Taranis case and assuming it's a LSD I'm pretty much covered for the whole flying season here in LA.

Just thinking about this 400Ma charge controller and the 100 min timer. I didn't look it up but I will, is the 100 min hard coded into it?
Where I see trouble is if Frsky changes the timer or charge current to accommodate the new 2000Ma pack they offer, will it eliminate the use of the 800Ma pack due to overcharging safety worries? Will the new 2000Ma pack become the stock one and eliminate the 800Ma pack?
That puts the first run owners in a strange position. They can't fully charge the new pack at one session and maybe Frsky would drop the 800 for a future OEM purchase?
Of course on can alway make their own 6 cell pack or charge externally every few weeks but I'm just thinking about the the stock options for those that just want to fly. They are well covered no matter what if they plug in the 12v regularly.
It wasn't so long ago we had to charge every time we went or were going flying. Now it's a bother every month ha ha.

Ok I read the specs as best I could and it appears that the 160 or 100 min max time limit is designed into the IC? So if that's the case is the only option left is to increase the charge current for the new 2000ma pack?
That or as Mike had pointed out, just replug the 12v 1 or 2 times to make sure the battery is topped off and fully charged if 2000ma or 2400ma?

Post by **MikeB** » Sat Oct 26, 2013 3:21 pm

It's hard wired, due to pin 1 being tied to ground. It should be tied to mid rail to give 160 minutes for a C/2 charge rate.

Mike.

Post by **ShowMaster** » Sat Oct 26, 2013 5:59 pm

It'll be interesting to see what Frsky does to provide got the new 2000ma pack?
Thanks Mike. This is all much to do about nothing being that we have so many battery options and fast chargers or just charging once a week.
A long way from the 600ma high self dischRge nicad days. I stored my radios plugged into their chargers and on a timer that cycled on a hour a day so I was always ready to go. I also replaced them every 2 years due to overcharge damage concerns. That I don't miss.

Clivew · Post by **Clivew** » Sat Oct 26, 2013 10:34 pm

MikeB wrote:It's hard wired, due to pin 1 being tied to ground. It should be tied to mid rail to give 160 minutes for a C/2 charge rate.

Mike.

A couple of 10K's perhaps?

Or maybe just wait and see what Frsky do on the latest Taranis (as SM said) and copy it

Post by **ShowMaster** » Sat Oct 26, 2013 11:45 pm

Maybe someone knows where the IC is located?
If it's on the switchboard that's now a spare part purchase. I admit, I'm fishing here a little to avoid opening up my case and looking for it.
Maybe the charger is a separate board?

Clivew · Post by **Clivew** » Sun Oct 27, 2013 12:04 am

Picture here SM

http://www.alofthobbies.com/taranis-power-switch.html

Looks as if it's all on there?

Post by **ShowMaster** » Sun Oct 27, 2013 2:11 am

Clivew wrote:Picture here SM

http://www.alofthobbies.com/taranis-power-switch.html

Looks as if it's all on there?

Perfect!
So I wonder what the charge values on this board are set for?

openrcforums