rgormley

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Hello,

I need some help with the use of a Tunigy Accucell 6. (if there is a “how to” that someone can point me to i`m happy to read through it)

Ok my questions….

I have a 8 way series AA batt holder that I have 8 banana jacks on so I can charge 1,2,3… or all 8 batts if I choose. I`m for example trying to charge 2 x AA nimh 2700Mah batts (imedion powerx)

What I cant figure out is what settings to use on the Tunigy Accucell6.

I need to know max charge current, and max upper charge voltage. the time for charging will be based on how flat they are I presume?

People talk about 1C charge rates (2.7 amps for 1 hour?) or 0.5C (1.35amps for 2 hours)

If I charge at these rates the batts get VERY hot and have to stop the charge. The voltage was rising to 1.8 volts or more, I presume this is way to high…

Discharge current (1A) is the highest discharge rate so I cant go wrong there.

The lower cut off voltage?? Will be 0.9v for a nimh?? and I just multiply this by 4 (if doing 4 in series?) so 3.6v as lower cut off?

The upper max charged voltage? Don’t know, will this be determined by the amount of current being pushed in the battery and time.

(why does the Tunigy Accucell6 keep pushing voltage up so high (1.8+ volts) when charging?

Anyway I think you get the idea of my questions so any help would be great…

if more info is needed at to what i`m on about or trying to achieve, yell out and i will post back..
Regards,...Richard

guver

My Feedback: (325)

Hi, and welcome to RCU. It's pretty cool to be able to charge aa in a holder like you're doing. You have a nice setup if it will do any number of cells up to 8. I like that. Even though many like to use a 1C rate it is too much for long skinny radio cells like AA cells. You probably want to keep it below 500 ma for those cells AND that is also why the voltage is reading so high AND that is why they are getting hot. The skinny connections and spring connectors don't help either , they make the voltage climb even higher.

If you use 500 ma for a 4-5 hr charge then most of the trouble will go away. The charger doesn't have an upper voltage limit on charging nor does it have a setting for number of cells when charging does it?

Ooh, There's one rule that should be followed when series charging cells together and that is they really need to require the same amount of capacity. IN otherwords all cells need to be at the same level of charge (like empty) I hope this helps you out. I think you have the discharge set ok already. There's no need to discharge.

opjose

The Turnigy Accucell 6 is based upon the iMax B6 charger.

Any of the manuals for the iMax or any of it's derivative chargers ( Venom, E-Flite, etc... ) will provide better instructions than what was included with the Turnigy.

I have one of the four port chargers and I just used the iMax manual instead.

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You mention a AA holder.

Typically it is not a good idea to charger batteries like this. Yes in effect if you have a set of cells in series or parallel you are effectively doing the same thing...
But pre-wired cells have been put through the same charges from the on set and tend to stay balanced... not so with loose cells.

You really need to make sure the cells are balanced for that sort of configuration and frankly it's not worth the hassle for loose cells.

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How is your AA holder wired?

If in series you will have to keep the capacity the same but increase the per cell voltage.

e.g. if you have two 1.2v NiMH packs of 2700mAh capacity in series you will need to charge them as a single 2.4v 2700mAh pack...

If they are wired in parallel, then you will need to charge them as a single 1.2v 5400mAh pack.

In the first case the 1C rate will be 2.7a and in the second 5.4a.

But as Guver stated, I'd keep the charge rate down to 500mA for NiMH packs.

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You have the cutoff correct for a series configuration.

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The charger WILL push the voltage higher at the start as it tries to detect the battery state.