charge time

[PandaBear]

Just a bit of reality check here, Jamie – Tomy’s TX charges the battery in 45 secs. By experiment we think a double charge gives the best result… ie 90 secs – let’s assume this is “full” charge. So to pump 50mA into that little battery in 90 secs… you already need 2A.

Test the current yourself if you like. Connect 2 fresh AA alkalines to 1 nicad and the current is approx 1-2A, depending how flat the nicad is. Use 2 fresh AA nicads instead and the current jumps to 2-3A.

Dunno what Tomy’s fancy electronics does apart from timing; but if you connect battery to battery like some guys are doing then the only thing that limits the current is the internal resistance of the cells.

About 15 yrs ago I bought some car+track set (like Bit Racer) using same size 1/3 AAAs. This one’s charger held 3x C-batteries which charged up the car in 20 secs (user-timed!)but they did wire up a small ricegrain lightbulb in series with the charging circuit.

But I entirely agree with you – RC nicads don’t have an easy life! We run them waaaay outside of factory specs… I’m sure Sanyo & Panasonic don’t like us charging our bigger subCs at 8-12A then draining them at 30-40A!!

[Admin]

If you charge the cell at 1 A it will self destruct. Trust me, 1ts 20C , wheres the max is about 5C.

[PandaBear]

Easiest is to whack your ammeter on and see… (hint:- use the 10A setting first).

[PandaBear]

Quote:

CORRECTION by PandaBear

To DOUBLE your TX’s charge time, they say to replace C3 with a 47uF capacitor (for our 3V the cap can be of any rating, lowest/cheapest is usually already 16V).

Make that “C2″… :smiley9:

Quote:

But me thinks… the original is 22uF. There is no harm in ADDING another 22uF or 27uF capacitor in PARALLEL piggyback with the original one and that should do the trick too. That way you can easily reverse the mod if you need to, saves work too.

Okie… have DONE that!!! :smiley10:

[Admin]

Yeah i know what you are saying. When i charge my vehicle/plane packs I put them in a soft wine cooler which helps regulate the temp, and allows me to charge at higher current. Cause I hate waiting!! I don’t like the primative controller charger…but you cant use deltapeak, or “smart” chargers, because the reciever is always drawing current, and they don’t like this.

Someone tested the charger on the TX, and it chaged at about 400mAh, which gives it just a ‘zap” of power. Thats why I get 5 mins with TX charger, and 20 mins with electronic stand alone charger.

[Admin]

And by the way, my home made electronic charger, cost less than 5 dollars…..

[PandaBear]

Quote:

Originally posted by jamiekulhanek on 22October2002

Someone tested the charger on the TX, and it chaged at about 400mAh, which gives it just a ‘zap” of power.

I find the current is highly dependent on type & freshness of the batteries in the TX, and also how charged your BCG is at the time. (My max current was with fully-charged 2x NiMh and a totally dead Bit – I got spot of about 1.5A!!)But either way… yeah, DON’T use the 200mA setting on the multimeter – definitely will blow the fuse. :smiley1:

Have now got “switchable” std/double charge time on my TX now. Timed it manually:- Std = 49s, Double = 1m40s. Car doesn’t really go any faster, only about 50% longer.

Picked up a plugpack for charging 4.8V “Jet Hopper” packs (pumps out 400mA)… methinks might be handy for home charging – time to do more experimentation. Was only $0.50 too.

[PandaBear]

Quote:

Originally posted by jamiekulhanek on 22October2002

I don’t like the primative controller charger…but you cant use deltapeak, or “smart” chargers, because the reciever is always drawing current, and they don’t like this.

I’ve still got an ancientKyosho LambdaPeak from when deltapeaks first came out for RC and this is super-sensitive, so I know what you mean. Its even sensitive to input voltage so its can be run off 12V battery only, not even a regulated powersupply.

But the RX takes a constant current and its very small anyway, so I don’t think it’ll adversely affect the modern smart chargers. As long as the car doesn’t pickup any TX signals and activate coil or motor, it should be ok.

Unfortunately I’ve got tons of different chargers for RC packs but I haven’t got anything that’ll peak a single cell. I’ve got a single-cell charger for my gloplug but this pumps out 5A into a subC 2000mAh… haha, yup this’ll totally nuke the Bit cell.

Ahh, I’ll just stick to the mod’d TX.

[Admin]

Anything is worth a try….just means replacing the internal battery mor often if you charge it too fast..but they are only like 3 bucks each so what u got to lose?

[PandaBear]

If you nuke the cell it *could* spew nasty caustic liquid all over the electronics… that wouldn’t be very nice. Then again, there’s only so much volume in that tiny cell… :smiley2:

Actually, bit of lunchtime dreaming here… what if we could make that battery easily removable (like RC packs), then can charge them offsite and the BCG can run continuously. ENDURANCE RACING??!! Hmm… maybe cut a hole on the side, heh heh heh.

[Admin]

the faster you charge the cell the less capacity it has

if you charge it fast you need to cycle it. The manufacturer recommends every time u charge it you should cycle it..bugger that, every 20 odd charges might be ok

[z-beam]

what is cycling?

I just fitted NiMH cells into my bits and they work great on a double charge. whats the limit on how many times i can charge it in a row with the standard controller?

[Author]

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