Please recommend a good charger for AW C Li-ion

[Tessaiga]

I have tried the search function but did not get a satisfactory answer. I know there's a group buy for a cradle that will plug into the Ultrafire WF-139 charger, but is there a better solution than this??

 

[monkeyboy]

The best option is to buy a RC model Li-ion/ li-poly balancing charger. There are lots of different models available but they're not cheap. For the cradle, you could strip out an old charger. This is probably the only way of charging these batteries at the maximum 1C charge rate.

 

[max52]

I use a Triton for my Lion "D", and AW "C" cells. I am conservative and charge at 2.5 Amps at 3.6V which terminates the cells at 4.12V. You can charge to a higher voltage if you want reduced battery cycles. I use my Ultrafire for 18650s which terminates at 4.18 which is the high limit I want for battery life.

You can also use the MAHA C777PLUS for Lions. It terminates C, D, Etc, at safe levels below 4.20. It is slow. Prior to getting a triton, I used the MAHA for my D lions with no problems. The D Lion is great cell. I have 4 I use in 2, 2D Mags. Great flexibility.

 

[mudman cj]

I bought one of the cheaper RC chargers for LIPO packs, and I haven't been able to get it to charge at the rates recommended for C and D Li-ion cells, so I went a different direction. I bought a HY1803 power supply that can deliver 0-18V at 0-3A with current control.

You can then set the current limit to the appropriate level and the voltage to the desired cell voltage and terminate charging once the current drops to 0.1 to 0.05 C. I am going one step further - a CPF electronics guru is designing a circuit for me to automatically sense the charging current and terminate charging at the appropriate time. Once I have it working I will share the results and plans.

 

[mansell2]

This is the thread I've been looking for... I want to run AW C cells but need a good charging solution. My kids also have some RC trucks - so a RC charger could serve dual purpose for me. I want a smart and safe charger where I can insert battery and walk away with peace of mind that the charger will shut off automatically. Is the RC charger of power supply better for my needs? I am willing to pay more for the peace of mind and dual function. How many cells can be charged at a time? Thoughts?

More questions. Can you charge multiple cells in parallel? Could you sent charge current to all and then have a electronic gate that shuts off current to each bay as it reaches its target? I would like to charge a minimum of 2 C cells at a time. 4 cells at a time would be great.

Thanks!


mansell2

 

[mudman cj]

Well, I finally got my power supply and charged a C cell last night. I noticed that since the cell started out with a pretty high open circuit voltage (3.9x V) the charging current was no where near 2.5 Amps with 4.20 V applied. Now it all makes sense to me. I thought my LIPO charger was not properly sensing cell capacities because the charging current was less than what I expected to see, but I should have realized that charging currents will be higher when the cell is at a lower voltage assuming the charger applies a fixed potential (4.20 V). The cells have an internal resistance that dictates the charging current according to V=I*R, but in this case V=Vcharger-Vbattery.

So, I charged one of the C cells using the power supply and the other on the LIPO charger. The LIPO charger terminated charging at 4.19V, and I was able to also charge to 4.19V using the power supply. My next experiment is to have a 'race' and record charging times for each charger starting from nearly fully depleted cells. I will report the results.

mansell2 - Charging Li-ion cells in series, especially large ones, is not recommended. However, you can charge in parallel if the charger is able to still terminate charging at the proper point. I have not yet tested this with my LIPO charger, but that experiment will be next on my list.

 

[mudman cj]

Update: My Graupner LIPO charger can charge AW C cells, though it takes longer than a power supply (PS). With my PS set to 4.20V, it took 2.5 hours to charge from 3.61V to 4.19V. Ending current was 260mA. The Graupner took about 5 hours to charge a C cell to 4.18V starting from 3.64V. I repeated the experiment with the Graupner a couple more times, and the termination voltages for all charges were 4.13, 4.15, 4.18, and 4.19. I wish that it were more consistent with termination.

I tried charging a pair of C cells in parallel using the Graupner, but charging terminated with the cells only measuring 3.89V.

I am looking forward to the automatic charge termination circuit for my PS. And I expect the PS with termination circuit to have no trouble charging a pair of C cells in parallel, though I have been wrong before.

 

[mansell2]

I'm just placed orders for the following setup. I ordered this charger (specs / retailer) . I also ordered 2 temp probes.

I liked this charger because it as 2 outputs and can charge 2 batteries at one time. Then I ordered this c cell battery holder. It can be ordered from this page. The holder is for 2 c cells in series. I plan to clip the rear coil to seperate the cells. I will then conncet the left battery to one of the charger outputs and the right battery to the other. I read a review that stated it can supply up to 2.0 amps per output of LiPo packs.

mudman cj, what do you think?

mansell2

 

[mudman cj]

That looks like a great setup!

I read through the manual, and I like the versatility of that charger. It will charge at constant current until a cell voltage of 4.10V, at which point it switches to constant voltage. This allows for fast but safe charging. During the constant current portion of charging, you can manually set the charge current to 2 Amps for each of the 2 C Li-ion cells.

You should be able to charge 2 fully discharged C Li-ion cells in about 2.5 hours or so, with 90 minutes of constant current charging to get the cell to about 88% charged, followed by nearly 60 minutes of constant voltage charging to top them off.

Regarding the battery holder, it looks like clipping that wire would work, provided that the left spring would stay put in the housing - perhaps a little epoxy will be in order.

 

[021411]

I'm just placed orders for the following setup. I ordered this charger (specs / retailer) . I also ordered 2 temp probes.

I liked this charger because it as 2 outputs and can charge 2 batteries at one time. Then I ordered this c cell battery holder. It can be ordered from this page. The holder is for 2 c cells in series. I plan to clip the rear coil to seperate the cells. I will then conncet the left battery to one of the charger outputs and the right battery to the other. I read a review that stated it can supply up to 2.0 amps per output of LiPo packs.

mudman cj, what do you think?

mansell2

mansell2, I put together something similiar to your setup today. I bought a Triton Jr. charger and connected it to a single C-cell holder. I'm gonna do some more shopping tonight for a few things.
So far so good. I need to get a dedicated power supply though. I ran the charger off of my car battery today.

 

[mansell2]

It looks like we are starting to get some different setups posted. I initially steered away for a AW C project due to no simple charging solutions. I just ordered 2 C cells the other day and I'm waiting for my charger setup. It seems like 18650 is the way to go for simple charging, but now I'm excited about the c cells. I'm surprized there isn't more posted on CPF about charging solutions for AW C.

 

[gswitter]

I'm hoping this solution will work as well for me as it has for others.

 

[mansell2]

Update: Here are photos of my setup. I am very happy so far. You will notice the DSD charger (reduced to 18650 holder only) and the C holders on either side. The left dsd slot and left C holder are wired together. The same with the right side. This setup only charges 2 batteries at a time. Either 2 18650 OR 2 C size. I wired it this way for my convinence. The power supply on left comes with the charger. You can unplug the A/C power supply from the cahrger and use supplied aligator clips to connect to your automoblie battery. This charger can handle Li-Ion Li-Po NiMH or NiCD. Hope this helps.

 

[mansell2]

[Major Edit!] Tronic alerted me that this single charger will not charge 18650 without modifying the arm. C size okay 1850 needs mod. With that in mind I have abandoned the idea of using this craddle and I plan on modding a large / 4 slot cradle. [End Edit]

Need help with making my setup better. I just finshed reading the huge Li-Ion Balance charging post which mudman_cj linked to here. While browsing this post I saw the following photo.

Wow. 2 of these would make my setup much cleaner. Where can I get this or similar. Each craddle would need to be able to handle C and 18650 (plus others) Li-Ions. The bannana clips would plug right into my charger. I'm thinking with 2 of these my setup could be an intermediate level charger setup requiring minimun or no soldering. Thanks for the help.

 

[barkingmad]

Need help with making my setup better. I just finshed reading the huge Li-Ion Balance charging post which mudman_cj linked to here. While browsing this post I saw the following photo.

Wow. 2 of these would make my setup much cleaner. Where can I get this or similar. Each craddle would need to be able to handle C and 18650 (plus others) Li-Ions. The bannana clips would plug right into my charger. I'm thinking with 2 of these my setup could be an intermediate level charger setup requiring minimun or no soldering. Thanks for the help.

Conrad Electronics sell them - they are based in Europe AFAIK - think someone was offering the 4 slot version as a group buy as well?

 

[jch79]

think someone was offering the 4 slot version as a group buy as well?

Does anyone have a link?

I can't find this group buy anywhere, and I hope I'm not too late!

john

 

[petrev]

Does anyone have a link?

I can't find this group buy anywhere, and I hope I'm not too late!

john

Hi John

PM Tronic

he has been sending both types to the US lately

I can offer the following:

Voltcraft Cradle $19/piece

Shipping option:

Option 1:
Economy Mail with insurance and Tracking to USA (takes 7-15 day to arrrive)
1 Cradle $21.50
2-3 Cradle $33

Option 2:
Priority Mail with insurance and Tracking to USA (takes 3-7 day to arrrive)
1 Cradle $33.50
2-3 Cradle $44

Note: I can only ship up to 3 Cradle in one package.*


Payment with Paypal only.

Paypal Cash: Add 2.5% (currency conversion fee)
Paypal CC: Add 5.9% + $0.45 (Paypal and currency conversion fee)

I am very busy at the moment and it can take 2-3 days until I ship the package.


Who is still interested?

-Daniel


*Up to 3 Cradle can be shipped as letter and it can simply be declared with the CN22 customs form.
But there is a 2kg limit and everything over that must be sent as a package and have to be declared with a way-bill.
unfortunately I dont have any experiences with this and dont know how to do this.
But If you need more than 3 just let me know and I will check this with my post office.

More info

Day to Day - DN/Tenergy4P, FMA-Cellpro/HD6S and Voltcraft Balanced Sys. Charging

Voltcraft Li-Ion Battery Holder - Newbie Modding Guide for upto 68mm cells mod

Lots of links and lots of reading . . .

Cheers Pete