Looking for charger recommendations

[^^Nova^^]

Hi,

I am in the process of building a ROP from a 4D m@g with 6 sub-c NiMH batteries and need to find a good charger for these. I also will probably make a 2D version (ROP or maybe P7 led) with a 6aa>2d pack.

Should I get one charger that can do both of am I better off getting a separate charger for both. I assume I can charge the 6 sub c's with a pack charger?

It seems anything that can charge c/d sized batteries gets fairly pricey. I have found a Maha C808 (can't remember the exact model) but that is $AU170

Should I look at one that can do LiON also? :duck:

Cheers,
Nova

 

[qwertyydude]

I have a pro-peak prodigy II. It should be significantly cheaper than a maha. Has charge, discharge and cycle features. Can charge Nicd, Nimh, Li-ion, Lipo and lead acid. I got mine at my local hobby store for only about 60 bucks. Don't know how much that would be Aussie but it should be available down under too for relatively inexpensive.

 

[geek4christ]

I think going with a hobby charger would be a nice investment for you. Just spend some time on some of the hobby forums reading about different chargers. http://www.rcgroups.com and http://www.wattflyer.com are two good places for information on what the rc folks are using.

And here's a link that lists a load of chargers to get you started: http://progressiverc.com/Charger.html

You know what your needs are now (6s NiMH), and it would probably be a good idea to plan for what your needs may be in the future. Pick a charger from that list that meets your needs, gets good reviews and has good support behind it (hint: stay away from hobbycity if you can...they most likely won't give you the support you want if something happens to your charger).

Following all that, you should end up with a nice charger that will last you a long time.

 

[^^Nova^^]

Cool, so charging as a pack would be fine? I keep reading about balance taps, I guess I'll have to check out some rc forums to clear this up.

Cheers,
Nova

 

[geek4christ]

Hi again, Nova,

Charging a NiMH pack is just fine without balance taps. Balancing is really only important for lipos and lithium-ion packs, where there is a chance of catastrophic failure of the cells if they get too far out of sync.

The thing to do is go ahead and charge your NiMH pack in the 0.5C to 1.0C range for your regular charges. Then every 10-20 cycles give the pack a nice long 0.1C charge for about 16 hours. This will serve to balance the cells as the more robust ones will simply absorb the overcharge while the others catch up to full.

This might be a little harder depending on the charger you select. To accomplish the slow "balance" charge, you will want to the ability to set the charger's peak sensitivity. If the peak sensitivity is not adjustable, then there's a chance that even with the slow 0.1C charge the pack will peak enough to signal charge termination. In which case the cells with less charge won't be able to catch up with the fuller ones.

If you do get a charger with an adjustable peak, then just crank that peak setting up as high as it will go and make sure to pull your pack after 16 hours. In that way, you won't be unnecessarily overcharging any of the cells.

Balance-charging lithium-based cells is a whole other discussion. If you think you'll be charging a lipo or li-ion pack, do make sure to get a charger with a quality, accurate balancer built in.