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Feb 14, 2013, 09:45 AM
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Discussion

recommendation for 300 mah AAA NiMH ?


I hate starting a new thread for something this basic (for most of you) but I just cannot find a clear answer. I need a charger for a 300 mah AAA NiMH. I just want the most basic charger that I need but there seems to be information overload about this. I am really a newbie when it comes to NiMH batteries. One that I saw recommended was this one: http://www.hobbyking.com/hobbyking/s...idProduct=7028

...but at the end of the page, it says that no power supply is included. Huh? If there is no power supply, what would one need to charge the batteries with? I have a Hitec Laser 4 tx ordered so is it possible to plug the batteries into that? I just know very little about these. Thanks to anyone who can help.
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Feb 14, 2013, 09:58 AM
Registered User
There are many ways to charge nimh. Simple slow wall chargers like come with a tx work just fine too. For a slow charge it should be C/10 rate, so for 300 mah batteries your charger should provide about 30 ma rate.

Most chargers run off 12v DC and need a power supply for home use. For the charger you linked this would be sufficient:
http://www.hobbyking.com/hobbyking/s...er_Supply.html
Feb 14, 2013, 11:05 AM
Registered User

How about ....


Grim, thanks for your reply. Someone local has this Hangar 9:

http://charlotte.craigslist.org/tag/3575196562.html

My recommendation for this 4.8V 300 mah battery says to "Set Delta Peak to 0.01-0.02V for adjustable chargers" but I do not see any setting on the this type of charger for that. Does that mean I don't have to bother with that or is this charger not right for me? There is also this one on Ebay. Thanks again.
Feb 14, 2013, 11:26 AM
Registered User
You won't be able to change the delta peak on that Craigslist charger and it's important to note that the settings are different for nicd then they are for nimh. The specs say "including the new breed of Nickel Metal Hydride batteries", had to chuckle, that must have been written long ago. Also that charger says it charges at 800mA which would be a bit rough on a 300mah nimh pack. It trickles at 80mA which is higher then the C/10 trickle should be.

Do you need a quick charging peak detect or will a slow ~14hr charge do?
Feb 14, 2013, 11:36 AM
Registered User
Honestly I would just get the Accucell6 out of the HobbyKing US warehouse, you can adjust the delta peak in the settings as desired (see manual) and set the proper charge rate at 1C of 300mA.

http://www.hobbyking.com/hobbyking/s...arehouse_.html
http://www.hobbyking.com/hobbyking/s...arehouse_.html
Feb 14, 2013, 11:46 AM
Registered User
flydiver's Avatar
Those are REALLY.......small.....batteries. What are you using them for?

I wouldn't even attempt to charge those with a delta peak type charger. I have that charger, use it for NiXX charging all the time and would not frustrate myself to use it on batteries that tiny. None of those type will 'throttle down' well enough to do the job reliably. The one you are listing is fine but it's lowest setting is 100mA, about 3x what I'd recommend for those batteries. You can use it but you best watch it and remove when the batteries warm up (see links below).

I'd find a small wall charger appropriate in voltage and output for your application in an electronics recycling or thrift store and solder on the proper connector (yes, you need to solder in this sport). Read this over:
Wall warts for charging

For a lot more info read here:
Technical Tips for NiCd and NiMH Battery Pack Users

Note: the Laser should come with a charger. SOME TX chargers also have a lower output (like 50mA @ 4.8v) output for an RX pack. That would be suitable for your application (assuming it is an RX pack you will be using) if just a tad high. I'd watch the batteries for warmth and pull it but the 'window' of safety will be a lot larger than with 100mA.
Last edited by flydiver; Feb 14, 2013 at 11:51 AM.
Feb 15, 2013, 12:45 PM
Registered User
Quote:
Originally Posted by grimbeaver
You won't be able to change the delta peak on that Craigslist charger and it's important to note that the settings are different for nicd then they are for nimh. The specs say "including the new breed of Nickel Metal Hydride batteries", had to chuckle, that must have been written long ago. Also that charger says it charges at 800mA which would be a bit rough on a 300mah nimh pack. It trickles at 80mA which is higher then the C/10 trickle should be.

Do you need a quick charging peak detect or will a slow ~14hr charge do?
Just got back on the forum. I will have 2 batteries and maybe more later so a quick charge is not all that important to me. Thanks for the info on the Hanger 9 charger.
Feb 15, 2013, 12:47 PM
Registered User
Flydiver, I am using the batteries in a very small Alula discus launch glider. It will weigh around 7 ounces. You state "The one that you are listing is fine" but I don't follow. Did you mean the one listed on Ebay? Thanks.

Quote:
Originally Posted by flydiver
Those are REALLY.......small.....batteries. What are you using them for?

I wouldn't even attempt to charge those with a delta peak type charger. I have that charger, use it for NiXX charging all the time and would not frustrate myself to use it on batteries that tiny. None of those type will 'throttle down' well enough to do the job reliably. The one you are listing is fine but it's lowest setting is 100mA, about 3x what I'd recommend for those batteries. You can use it but you best watch it and remove when the batteries warm up (see links below).

I'd find a small wall charger appropriate in voltage and output for your application in an electronics recycling or thrift store and solder on the proper connector (yes, you need to solder in this sport). Read this over:
Wall warts for charging

For a lot more info read here:
Technical Tips for NiCd and NiMH Battery Pack Users

Note: the Laser should come with a charger. SOME TX chargers also have a lower output (like 50mA @ 4.8v) output for an RX pack. That would be suitable for your application (assuming it is an RX pack you will be using) if just a tad high. I'd watch the batteries for warmth and pull it but the 'window' of safety will be a lot larger than with 100mA.
Feb 15, 2013, 01:24 PM
Registered User
flydiver's Avatar
The Accucel-6 in the first post. I have one and it's fine but it will only go down to 100mA and I seriously doubt it'll do a reliable delta termination on a battery small. But that's a guess. You can tune it and try.
Still, that's still 3C on a very tiny battery and I don't recommend it.
Feb 15, 2013, 01:28 PM
Registered User
Quote:
Originally Posted by grimbeaver
You won't be able to change the delta peak on that Craigslist charger and it's important to note that the settings are different for nicd then they are for nimh. The specs say "including the new breed of Nickel Metal Hydride batteries", had to chuckle, that must have been written long ago. Also that charger says it charges at 800mA which would be a bit rough on a 300mah nimh pack. It trickles at 80mA which is higher then the C/10 trickle should be.

Do you need a quick charging peak detect or will a slow ~14hr charge do?
I did not realize it at the time but the guy on Craigslist had 2 chargers and was trying to tell me that it would work and now I am thinking he was referring to this other one he had listed http://charlotte.craigslist.org/tag/3575188696.html That does sound like the right one for what I need.
Feb 15, 2013, 04:24 PM
Registered User
Quote:
Originally Posted by brett123
I did not realize it at the time but the guy on Craigslist had 2 chargers and was trying to tell me that it would work and now I am thinking he was referring to this other one he had listed http://charlotte.craigslist.org/tag/3575188696.html That does sound like the right one for what I need.
Lowest charge rate on that one is 0.5Amp which is still more then 1C (0.3A).


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