Chippy
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| posted on 4/11/09 at 11:43 PM |
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Making a battery charger?
Hi, I have tried to get hold of a battery charger that will charge a 14 cell 21V pack with zero luck. Would it be difficult to make one, and if
anybody has the required information would they do me a wiring diagram, or contact me by PM or email. Thanks Ray
To make a car go faster, just add lightness. Colin Chapman - OR - fit a bigger engine. Chippy
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splitrivet
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| posted on 5/11/09 at 12:04 AM |
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Use one of these
http://cgi.ebay.co.uk/Universal-DC-Power-Adapter-Charger-for-Laptop-Notebook_W0QQitemZ260501308234QQcmdZViewItemQQptZUK_Computing_LaptopAccessories_Po
werSupplies?hash=item3ca716834a
Just cut the end off and use insulated croc clips, cheaper than making one.
Cheers,
Bob
I used to be a Werewolf but I'm alright nowwoooooooooooooo
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MikeRJ
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| posted on 5/11/09 at 12:19 AM |
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Unfortunately that is not a stand alone charger, it's simply a power supply with a selectable output designed to replace a laptop adapter. With
most commercial products the charging intelligence is inside the product itself and/or the battery pack.
Charging NiMH cells properly (i.e. with reliable automatic charge termination) is surprisingly difficult. If you just want a simple constant current
charger that you manually switch off after a certain time or when the cells get warm that's rather easier.
This is a good ready made solution for a very reasonable price, but you will need a suitable power supply for it to use
from the mains. An old laptop adapter may well be suitable for this application (check voltage and current ratings though!).
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londonsean69
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| posted on 5/11/09 at 12:32 AM |
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14 cell and 21V?? Are you using 1.5V cells??
That strikes me as strange, most cells are 1.2V, therefore 15 cells would be 18V.
One of these could do 18V (15 cells @1.2V)
>>>charger
linky
I used to use an ansmann to do a 14 cell pack for a dive torch
Hope that helps
Sean
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splitrivet
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| posted on 5/11/09 at 09:01 AM |
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Mike that is ample to do the job in hand and would give exactly the same results as the original charger supplied with Ray's kit (a large
chinese made r/c car I believe).
The other charger would be better but I think if you factor in its cost and the the cost of a 12v supply to power it you could buy a brand new car
with charger.
Cheers,
Bob
I used to be a Werewolf but I'm alright nowwoooooooooooooo
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MikeRJ
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| posted on 5/11/09 at 01:03 PM |
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quote:
Originally posted by splitrivet
Mike that is ample to do the job in hand and would give exactly the same results as the original charger supplied with Ray's kit
If Rays kit was originally supplied with a regulated power supply and the charging circuit was built into the car etc. then it may well work.
However it's completely and totally unsuitable for connecting directly to a battery. It is a regulated power supply, NOT a charger, and hence
has no suitable current limiting or charge termination abilities.
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splitrivet
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| posted on 5/11/09 at 07:47 PM |
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The chargers supplied with those type of R/C cars had no current limiting or overcharge protection, I should know I used to sell them. It would be a
doddle to make a charge limiting circuit if required.
Cheers,
Bob
I used to be a Werewolf but I'm alright nowwoooooooooooooo
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Chippy
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| posted on 5/11/09 at 10:44 PM |
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Hi Guy's, well still in the dark, as the ideas so far don't seem to fit the bill. Looks like I am going to have to tell the grand kids
that its beat grandad this time, now that is a first. Thanks anyway. Cheers Ray
To make a car go faster, just add lightness. Colin Chapman - OR - fit a bigger engine. Chippy
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splitrivet
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| posted on 6/11/09 at 12:07 AM |
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quote:
Originally posted by Chippy
Hi Guy's, well still in the dark, as the ideas so far don't seem to fit the bill. Looks like I am going to have to tell the grand kids
that its beat grandad this time, now that is a first. Thanks anyway. Cheers Ray
Dont give up that easily Ray your Grandad after all, my grandkids think I can turn water into wine well into Coca Cola anyways and fix anything from a
matchbox car to a dropped Ipod and for them I have. Take it from me my solution will work, to make it more kid proof buy a DC connector socket from
Maplins and fit it into the car and tee it into the battery connections the charging must be timed though. If its 14 cell it will be 16.8v in saying
that if its been given to them its probably tatered anyroad.
Cheers,
Bob
[Edited on 6/11/09 by splitrivet]
I used to be a Werewolf but I'm alright nowwoooooooooooooo
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