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[J.beazley]

ive got a few chargers and only use 1 but which one is going to charge a battery the best and not take forever???

1= output 12v 200mA
2= output 10v 250mA
3= output 15v 300mA

by the way there charging 7.2volt buggy packs

Jay

[Ian Robins]

Hi jay,

personally I use a 12v fed battery charger supplied by either a computer power supply (400watt=16amp 12v) or a car battery
The chargers I use are
Robbe ultimate 1-24 cells i think up to 5amp input
 Jamara Charger brought from model power basically the same but cheaper

The robbe charges nicad,nickle hydride and also lead acid batteries
The Jamara charges nicad, nickle hydride and lipo cells

I try to set the charging rate manually to approx 1 hour charge  ie. If pack is 2000ma i set the charge rate to 2000ma and the battery is charged is approx 1 hour

chargers are a minefield, the only advice is to buy the best quality charger you can, but unfortunately you will probably spend approx £50
good luck

ro88o
NDMBC

[FullLeatherJacket]

3

[Ghost in the shell]

personally id use the 10v one, giving a 7.2v however best bet is a matched charger :) farradays cage is the one to ask

[Faraday's Cage]

Hi Jay,

Charger 3 will deliver more charging current to your cells so charging them faster.  If you divide the charging current by the size in milliamps of the battery pack you'll get an approx time to charge.

Therefore a 2000mAh pack would in theory take 10 hours to charge using a 200ma charger. It will actually take a little longer (14 hours would be typical) due to losses involved in the process.

Terry.

[J.beazley]

Thanks for the advice and info Terry, been pondering this for a while.
usually ive plugged the packs in and let the chargers do there thing until the little LED goes out which has always done me good out on the lake and given a fair run time.

i try to keep the "memory" effect down to a minimum by discharging the packs with a car headlight bulb, must be doing something right the packs still work.

Jay

[Faraday's Cage]

Carry on with what you are doing. Sounds ok to me.

Terry.

[OMK]

Therefore a 2000mAh pack would in theory take 10 hours to charge using a 200ma charger. It will actually take a little longer (14 hours would be typical) due to losses involved in the process.
Terry.

waht wood happen if you charge his 7.2 pack with the 10 volt charger. what happens if you charge it with the 15 volt one.

[Faraday's Cage]

waht wood happen if you charge his 7.2 pack with the 10 volt charger. what happens if you charge it with the 15 volt one.

The voltage output will be the same with both chargers as the internal resistance of the battery pack will regulate the voltage to around 8 to 9 volts max. Put a volt meter across the battery connections whilst charging and see.

Terry.

[OMK]

Aw, mate - I know already. The reason the Q was asked was because I was in one of those moods. Wanted just for once to type without punctuation. So many are doing it that I wanted to know what it felt like.
And also because, in his reply, Ghost' said: "Faraday's Cage is the one to ask.". Since your avtar omits the apostrophe in "Faraday's", I was praying that your electronic know-how wasn't as iffy. Seems not. In which case you and I, then, are not members of Ghost In The Shell's acronym. ;-)

Since the thread question was one of battery charging time, FLJ was the one who answered spot on first.
Didn't you admire the way his one-character reply spoke a whole volume?

[kayem]

Since the thread question was one of battery charging time, FLJ was the one who answered spot on first.
Didn't you admire the way his one-character reply spoke a whole volume?

Well, now you're asking. Offhand, I can't think of a single person on this Earth that I admire as much as Mr Jacket.

[Colin Bishop]

Well, now you're asking. Offhand, I can't think of a single person on this Earth that I admire as much as Mr Jacket.

Ah! So we've got one of the double identities at last! 

[Faraday's Cage]

Since your avtar omits the apostrophe in "Faraday's", I was praying that your electronic know-how wasn't as iffy.

PMK,

What's an avtar ?

If you're going to take the p**s then at least check your spelling first 

Oh, and just for you, I've now "corrected" my avator.

Terry.

[FullLeatherJacket]

Ah! So we've got one of the double identities at last! 

Admiral
Afraid not. Check with Mayhem; he gave me my only current nom de plume. Can't speak for Kayem. Wouldn't presume to.
PMK
 

[Colin Bishop]

Admiral
Afraid not. Check with Mayhem; he gave me my only current nom de plume. Can't speak for Kayem. Wouldn't presume to.

I know - just being aggravating - got a response though didn't it? 

Incidentally, are your smiley sunglasses Avatars or Aviators?

[FullLeatherJacket]

They're Ray-Bans, dude

[OMK]

What's an avtar ?
If you're going to take the p**s then at least check your spelling first

If you care to bone-up on the subject you'll notice the word can be spelt either way. Depending on your geographical location, it varies from forum to forum.
Avtar... Avatar... It's still a stupid-sounding word - however it's spelt/pronounced.

Anyhow, what's this about taking the pee?
Nah, you got it wrong, amigo. My words may come across somewhat cryptical at times, but there are no suggestions of mickey-taking. Quite the contrary, in fact. You know what an acronym is, right? Ghost In The Shell is an acronym for GITS. Since your reply concerning the battery charge times implied you had a modicum of savvy in your bonce, I was suggesting that nobody could accuse you of being a git. Geddit? However, since you were slow on the up-take, the compliment was maybe a tad generous.

Oh, and just for you, I've now "corrected" my avator.

That's fine. No need to thank me - just leave payment with my secretary.


Happy modelling / battery charging.

[Jankers]

If you are looking for superfast charging there is a way using the standard
car battery chargers that works for nicad 'buggy' (7.2volt) packs.

This method is contrary to all "correct" practise but was used for many years at the
club my son attended when racing buggy style rc vehicles.

Just use the (mains) battery charger direct to the pack, it will take whatever amps the
charger is capable of giving (I have seen 9.2Amps going into a 7.20v 600mah pack) and monitor the pack with a voltmeter.

The buggy practise was to cool the pack with a fan but this is not essential.

At 4 amp charging the pack should be near charged after 20 mins and it will get hot, the voltage will stabalise before dropping slightly. Monitor the pack and, as it begins to get hot, note the voltage (packs will differ), this  will be in the region of 8.4v (using a 4amp charger) if i remember correctly, at which point stop charging and let the pack cool.
The stop point is determined when the rate of heating overtakes the rise in voltage, hot is generally ok, very hot means stop immediately. This will coincide with the charging time .

important.. only use this method with "vented" cells. and ensure that you are on hand all of the time as overcharging will damage the pack, usually this will take the form of diminished capacity. This method has NOT been tested with nimh packs

This method sounds very aggressive but, with a little practise, one gets the" feel" (literally) for the amount of heat the pack can take, on chargers with higher charge rates than 4 amps i have seen packs recharged in less than 15 mins.

Although it is an aggressive method of charging I have had 6volt packs last for years with only a periodic drain and slow charge to counteract any "memory effect", it works with the "sub-c" cell ni-cad packs normally associated with buggy racing and it was common practise to charge a pack 4 or 5 times an evening. Despite this brutal treatment the packs only ever suffered if left unattended and thus overcharged.

J.

[OMK]

Excellent!
This is the stuff that conjures-up images of the cheque-book fraternity fouling their pants. They'll be scuttling to their next meeting with horror stories of "some bloke called Jankers charging his cells from a bog-standard auto charger!!".
For what it's worth, a gang of us around these parts have been charging our cells thus for yonks. Gel-cells... Ni-Cads... Ni-MHs... you name it. No-one uses them over-priced, all-singing, all-dancing charging gizmos anyway. All it needs is just a standard auto charger, a voltage meter (if you're posh) and a dose of common savvy.
One chap had charged his Ni-Cad pack this way at least ninety-million times. It finally burst into flames when it got overcharged while he took a pee behind the hedge. If nature hadn't intervened, he'd still be using the same pack.


Nice work, Jankers.
You's da man!

[Faraday's Cage]

PMK (or should that now be Captain PMK),

I was a bit slow on the uptake previously. Now I get it !  Sorry.

By the way, are those circuits your design are your associated web site ?

[Jankers]

Thanks for your kind comments PMK.

At the time I was practising thischarging method, (about 20 years ago)
Nicad packs were (relatively) expensive so few  of the clubs members had more than
two packs, one of which was on charge whilst racing and marshalling.

That took about 12 minutes then back to the 'pits' to monitor things and mess with the
vehcle. twas a rather hectic, but enjoyable, ecening out.

J.

[HS93 (RIP)]

I started 12th scale cars 1979/80 and at that time the nicads where all 1.2 ah most people charged them for racing at 4 ah constant current ,depending on the circuit .you could also charge for 10 min then peak the last few min at 5ah  to give a kick of the line.At the euros in 1982 some people where seen charging straight of a car battery with the nicads in a bucket of water to cool them again they where peeked. at this time standard motors where run in bl placing them in a glass of water and run for about 10 seconds ,this bedded the brushes in very fast without burning them .the problem was that they rusted very fast... even if you cleaned them in trike
which was not very good for your lungs.it was a year or so before Ever Ready brought out 1.4 ah cells and they became legal but they would not give up all there power quick enough ,and so it was a few years later befor cells started to improve . by this time 12th scale had lost a lot of people to buggy's and the clubs died out in a lot of areas. Peter

[Glyn Cleaver]

3 but it will probably melt something important. 

[J.beazley]

blimey the replies are interesting to read, very good info being put across cheers lads.

Another question is ive got a normal car charger that will charge at 6v or 12volts and only puts out 6 amps (not that i would charge my SLA with it ) could i charge my 6volt 12ah SLA with it?
waiting to raise some funds before i get a proper SLA charger as need a new car first ::)

Jay

[Shipmate60]

Put simply.
NO.
If you want SLA batteries charged just drop them round.

Bob