charging batteries help

[diehard]

ok guys im calling for your expertises again.

i just got a swallow advance battery charger and i have no idea how to setup the settings for charging and discharging so what i need to know.

1. How many amps should i set the charger to discharge a 3300MiMH 7.2v pack.how long do you think it will take??

2. Also how any amps should i set it to charge 4 1000mah AAA bats?also discharge amps.

i was told to set it to 4-5amps when charging the 7.2 3300 packs is that right for about 1hr. how does that sound?

[leonli17]

1. A 3300NiMH i assume is a 6cell Sub-C pack. for discharge the Swallow only goes to 10Amps so just set it at 10A. it’ll take a good 20mins if your pack is healthy.

2. To charge AAAs i think 1A-1.5A max. That gives good punch and run time. Discharge amps would be around 5-7A.

Yes for charging 3300mah packs 4-5Amps are fine and it won’t take 1 hour possibly 40-45mins.

[klims]

although you can fast charge a pack in 1hr its never gonna be as good as a trickle charge. swallows only go down to 100mA so if you can afford to wait 10h for AAA’s to charge then do it. you can actually notice the difference if you take the time.

another problem with charging 4 AAA’s in series, i assume thats how your doing it, is that once again you will never fully reach the capacity of the batteries due to the mismatched energy densities. when a pack is made the cells are usually measured and matched to make a good pack. but i guess thats really getting too far into it…

[Dangerous Dave]

I go by a rough rule for charge rate of 1 – 1.5 C (C is the cell capacity, ie 3300mAh.. so 1C is 3.3A).

discharge rates I don’t know much about, but leo’s numbers sound fine 🙂

[betty.k]

that’s all good info.

once you get normal charging sorted then you can learn about tuning your cells.

eg: say you wanted your 3300’s to have lots of punch (voltage) for a race.
then you want to charge and discharge your cells hard. discharge at 35A and charge at 6A.

want runtime? charge and discharge gently, charge at 3A, discharge at 5 – 10A :8ball:

[diehard]

well im getting my 12v power supply tonight so im gonna have a bit off a play with the 7.2 packs. i was charging them before with just a regular car battery charger.hahaha there only crap 7.2 anyway.

what kind of run times are ppl getting with there 7.2???? back in the day when i got my 1st grasshopper(i was about 10year old) i was getting like 5-7 mins.lol

[klims]

12 power supply? so you didn’t get the V2 then…

how much did you pay if you don’t mind me asking?

[diehard]

umm i got it for 115 and i know that there cheaper on ebay but every now and then i dont mind paying extra for good service, the guy at herns hobbies in melb city has always had time for me for all my questions(and i always have questions, they know me as the mini z man lol) and they are always very friendly to me..

[klims]

yeah? you mean that guy with the hat? can’t remember his name.
he was nice to me while i was spending money there, then i couldn’t get my gas buggy running because i was a noob and he didn’t wanna know me. bit or a prick i thought.

[betty.k]

john 😉 :8ball:

[diehard]

yeah the dude with the hat(well every time i go there he wears one). he has a few mini z’s him self.

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