Ac - dc adapters

[HOTDOGHARRY]

Where is the best place to buy replacement adapters please?
Thanks
cliff

 

[amlu]

your local charity/junk/second hand shop. they have lots of them around.just keep an eye on voltage/current ratings...

 

[HOTDOGHARRY]

THANKS FOR THAT
Dont know if you can help but I have a 14.4v drill which came with a charger that outputs 18v is that ok being higher voltage and if the output is 400mA can I get an adapter with higher mA say 800mA and reduce charging time by half?
hope that makes sense
thanks in advance
cliff

 

[Marvo]

THANKS FOR THAT
Dont know if you can help but I have a 14.4v drill which came with a charger that outputs 18v

Did you measure the output voltage with the charger unplugged from the battery holder? Chargers will often test as a much higher voltage when there's nothing connected to the output so always measure the voltage whilst it's under load. Also the output of the charger could be pulsed or modulated so your tester might not be able to give you and accurate measurement.

I would just stick with a charger with the same specifications as the original. If you do manage to double the charging current either the battery will be damaged or it might even overheat and catch fire or explode.

 

[tazz]

The voltage to charge Nicad, Nimh batteries, is not critical, aslong as it is above the total cell voltage. Now manufactures ensure their charges suit the limits of their batteries, in regards to current charging and current limiting.....so changing psu is not recommended, and at extreme, may result in battery splitting or exploding.

 

[HOTDOGHARRY]

hi
thanks for your reply the 18v output is on the charger adapter but apparently this is ok, thanks for advice about doubling current
cheers cliff

 

[HOTDOGHARRY]

[....so changing psu is not recommended, and at extreme, may result in battery splitting or exploding.[/QUOTE]

cheers tazz

 

[HOTDOGHARRY]

have noticed sellers on ebay selling adapters with 1.5a output saying will be fine to replace anything below 1.5a say 500mA but that would be trebling output amps!!!
Are you saying this could cause problems?
sorry for my ignorance on these matters but want to get right adapter
cliff

 

[tazz]

Stick to manufactures....they have done the homework, and designed the chargers, to be compatible with their batteries, if you can find an alternative manufacture then all good, but only if they can guarantee compatibility......There are alot of batteries on the market....nicad, nimah and lion....all charged by current rating not voltage........Lead acid, is the opposite, charged by constant voltage

 

[HOTDOGHARRY]

thats the problem cannot find one with same rating of 400mA only 1.5A (WHICH EBAY SELLERS SAY WOULD BE FINE)
THANKS ANYWAY WILL KEEP LOOKING

 

[tazz]

If you check the specifications on the ebay seller im sure you can work it out

 

[telectrix]

the charger will be capable of supplying 1.5A, but the actual current drawn depends on what the battery requires. might only draw 300mA or so.the charger can't force excessive current to the battery if the voltage is within limits. e.g. for a 14.4V battery, you want a charger uotput ( on load) of approx. 16-17V.

 

[HOTDOGHARRY]

so with the amps it does not matter how high you go or is there any reason not to go much higher than original charger cable
thanks
Cliff