Model Boat Mayhem
Technical, Techniques, Hints, and Tips => Batteries & Chargers => Topic started by: jaymac on April 28, 2012, 10:42:52 pm
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Hi Just got my first electric boat today and would appreciate advice on the following
It has two 8.2 3000Ma Nimh packs assume wired in Parallel
(1) can I charge these in Situ and both together or better to do singly
Also the charger has four rates 1amp 2 amp or 4amp which would be the better to use the label on the pack says standard charge 10 Hrs @300mA and 1 Hr @ 3000 mA Thanks
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does the charger have a cut off when the battery is full?
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Hi Just got my first electric boat today and would appreciate advice on the following
It has two 8.2 3000Ma Nimh packs assume wired in Parallel
(1) can I charge these in Situ and both together or better to do singly
Also the charger has four rates 1amp 2 amp or 4amp which would be the better to use the label on the pack says standard charge 10 Hrs @300mA and 1 Hr @ 3000 mA Thanks
Charge them separately, from a discharged state at 4 amp for 45 minutes (if your charger does not cut out when battery is charged) :-))
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Scoop has given you a good answer. Please remember that your batterys will develope a memory effect which will reduce there capacity. So as he correctly sayes always fully discharge them. You could use a bulb to discharge. Battery chargers that will automatically discharge and charge your batteries do exist but not worth the cost. Better to buy later type batteries if required. The component shop is a good source. Have fun. John.
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NiMH
do not have a memory problem and can be charged
from any state of charge unlike the old NiCads
Ned
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As Ned says, your NiMH batteries will not develop a memory like the older NiCAD batteries so you dont have to completely discharge them before charging them.
Charge them when you like. :-))
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If the charger does not have a meter to indicate the actual rate of charge, then you really have no idea what is going into the battery. The choice of 1A, 2A, 4A is most likely a maximum limit rather than an actual regulated rate, but it is the sort of thing that needs checking with a meter.
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Im sorry that i got batteries mixed up. John
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Thanks Guys well Re the charger shutting off when complete the Gubbins on the box says With LEd and beeper to indicate charging status .This went Off about 90mins after charging my first Pack @1 amp this pack was not fully discharged before charging
The second pack @ the same rate took just over 3 hours
Box also says charging controlled by 8bits CPU microprocessor
And Re-Peak function Thanks again
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Sounds like the charger I have, it gives an audible warning when the battery is fully charged.
It would be helpful if you gave us the make and model of charger.
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Sorry thought I had its BMI Ultra Peak 4A art2129 I guess? once its beeped it goes on trickle charge hopefully
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I do have one of these.
Set the switch for 4amps, connect battery to charger, red light will flash to indicate trickle charge.
For fast charge, when light starts to flash push red button, red light will stay on but not flash.
When battery is charged the charger will beep, the battery should be disconnected at this point.
It is best not to leave unattended when fast charging in case battery gets hot.
Hope this helps.
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Thanks Richard so I must have fast charged Aaargh! must remeber to leave the button alone .Curious though Re 4Amps according to the BOX
Variable charging current AC 4-8 cells 1.2amps
DC 4-7 cells 1-2-4 amps
does that mean only 1.2 available on AC
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The AC current quoted will be the mains AC consumption of the charger
All batteries are DC
Ned
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Thanks Richard so I must have fast charged Aaargh! must remeber to leave the button alone .Curious though Re 4Amps according to the BOX
Variable charging current AC 4-8 cells 1.2amps
DC 4-7 cells 1-2-4 amps
does that mean only 1.2 available on AC
I always fast charge my batteries as I have so many I would need too many chargers to trickle charge them all.
My oldest batteries are six years old and still going strong.
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Variable charging current AC 4-8 cells 1.2amps
DC 4-7 cells 1-2-4 amps
does that mean only 1.2 available on AC
Since batteries are DC only devices, and have never responded well to AC, I have to guess that the letters used in this case mean something else other than Alternating Current and Direct Current.
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The AC current quoted will be the mains AC consumption of the charger
All batteries are DC
That is what I said :-))
Ned
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Guys I know batteries are DC but as this charger runs OFF AC or DC I thought perhaps this had some effect regarding output depending on input
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The mains AC input is converted to DC. The 12v DC input stays as DC but is probably regulated.
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Thanks Richard so I must have fast charged Aaargh! must remeber to leave the button alone .Curious though Re 4Amps according to the BOX
Variable charging current AC 4-8 cells 1.2amps
DC 4-7 cells 1-2-4 amps
does that mean only 1.2 available on AC
It means that from a DC source, you can charge 4-7 cells at 1, 2 or 4A
but from an AC supply you can charge 4-8 cells at 1.2A
Mark.
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Thanks Mark thats what I thought it meant