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Author Topic: Charging help.  (Read 2278 times)

hama

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Charging help.
« on: January 24, 2009, 07:28:52 pm »

Hello!
I have a simple charger that I've used for several years, it's labelled 12V 250mA. I use it to charge a 9,6V 1600mAh battery and I charge it for 10hrs because someone told me so I think. It works but is it correct? I plan to buy a 9,6V 2000mAh battery and wonder if I can use this charger and how long should I charge the battery? Would be very grateful for an answer as I am no good at this at all.
Thanks!
Hama.
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malcolmfrary

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Re: Charging help.
« Reply #1 on: January 24, 2009, 09:19:58 pm »

A lot depends on what is limiting its output to 250mA.  If its just that the transformer inside it has that limit, there could be a certain amount of luck involved.  The output windings will generate heat, depending on how much work they are doing - if the transformer can get rid of the heat faster than it is generated, no problem.  If the transformer gets too hot, the insulation starts to degrade and will eventually fail.
Your arrangement will probably work OK, but it might need a bit longer than the charge time you are using now.
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Shipmate60

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Re: Charging help.
« Reply #2 on: January 24, 2009, 11:25:30 pm »

hama,
Dedicated chargers have come down in price lately.
The basic Delta Peak chargers can be bought for about Ģ25.
They will fast charge till almost charged then drop down to a trickle charge for the final charge.
1 charger will normally charge from 7.2 volts to 9.6 volts.

Bob
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hama

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Re: Charging help.
« Reply #3 on: January 25, 2009, 10:59:34 am »

Thanks a lot for your kind answers! Seems like I should invest in a new charger as well then. Donīt want to set the house or the new battery on fire!
Hama.
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TCC

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Re: Charging help.
« Reply #4 on: January 25, 2009, 11:27:01 am »

Does he have to buy a new charger? If his old charger will do a new battery of the same type, it makes no difference what rating the new battery is, he'll just need to charge for longer, no?

I'm no good to you as I'm not that knowledgable on electrics but it went something like this:

if you have a 10 ah sla (sealed Lead ACID) and a charger that put out 50 mah, then 50 into 1000 is 20 thus 20 hrs and you always give it an extra hour.

So, 21hrs of charge to charge that battery with that charger.

Has someone got a list of these equations for:

sealed lead acid
Ni-cad
Ni-MH

?
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FullLeatherJacket

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Re: Charging help.
« Reply #5 on: January 25, 2009, 12:47:28 pm »

I suggest you might try my friend Iain's website http://www.component-shop.co.uk/ and then click on the yellow button "Batteries explained".
You can buy a decent charger for half the price of a 9.6v NiMH pack and know for sure  that it's going to do the job.
Suit yourself.

FLJ
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Seaspray

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Re: Charging help.
« Reply #6 on: January 25, 2009, 12:49:45 pm »

By the sounds of it ,its a ni-cd or Ni-Mh thats being charged.

The Pro-Peak is the one for that job. Al thou I've had the Pro-Peak shut down on trying to charge batts that has been discharged for a year. It is a delta peak fast charger and can charge both types of batteries.

I had to use my R/C Bike charger o/p dc 7.2-8.4v 1.2A to knock a little life into them so the Pro-Peak could read them and set of to do the charging.

Seaspray
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hama

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Re: Charging help.
« Reply #7 on: January 26, 2009, 10:24:03 pm »

Hi again! Thank you again for your help, component shop was a great find and I might use them in the future.
Perhaps I should have told you that the charger I was referring to was the one supplied with my Dickie tug, so it was meant to charge the supplied NiCad battery. After about a year I replaced the battery with a 1600mAh NiMh and have used the same charger for about 4 years without problems. Anyhow, now I need a battery for my Tenby and I want a little more endurance. I found a cheap 2000mAh one and I think it could be wise to invest in a bit better charger at the same time. At the same shop they sell a delta V peak charger that seem to suit me. Two questions;  1. The instructions on the internet state that it has a discharge button, is there any point in using his on a NiMh battery?  2. It has two charging settings, I guess this controls how fast you want to charge. How do I know whats right for my battery?
Thanks again!
Hama.
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Seaspray

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Re: Charging help.
« Reply #8 on: January 27, 2009, 08:35:09 am »

I think the discharge button  is for Ni-cds as they have a memory and if not discharged you could get a false charge. I've never had that trouble as I leave them in the Tx till they're flat. Ni--Mh don't have this trouble but I like to run them flat from time to time.

My Peak charger is easy. Just connect your battery and press the charging button and it fast charges light goes red. Connect battery don't touch the button it trickle/slow charges the light stays green. After a fast charge is complete it switches to slow charge green light but its old now, yours probably be newer.

 I don't discharge the SLA batteries only a trickle charge now and again cause if they go flat there finished.

Alternatively try FLJ link on Reply 5
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DickyD

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Re: Charging help.
« Reply #9 on: January 27, 2009, 08:43:19 am »

Hi Hama

The discharge button is for nicads which should be discharged before charging
The two charging buttons are one for trickle charge and one for fast charge.
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