cordless phone batteries

[ytre]

My old rechargeable batteries from my phone were AAA 550 mah 1.2v, i replaced them with 850 mah 1.2v but no power at all .
Tried the batteries in another device and working ok. Does the mah make any difference?

 

[mr_splatter]

Shouldn't do. This figure is just the capacity. What is the technology? NiMH? Are they fully charged? I replaced the batteries in something the other day and the problem was the initial charge. Some of the NiMH self discharge quite easily.

 

[ytre]

hi, there energizer nimh, fully charged them with the energizer charger. Im baffled.

 

[mr_splatter]

Then I am puzzled. The only other issue I have seen is the difference in voltage between these rechargeable and alkaline ones but I don't think this is the issue because you are replacing like for like. I bought a cheap battery tester from Lidl and it's been really useful because my kids get through loads of batteries and a small drop in voltage can be the difference between working and not.
Are you sure the charger actually charged them?

 

[ytre]

im assumimg it has when they worked in another device, im gonna leave it in the phone all night to see what happens. Thank you for all your help

 

[the snooper]

check the connections on the batteries some have more area exposed then others and dont match up with the device connections

 

[ytre]

just checked the connections and all are ok from what i can see

 

[the snooper]

if it worked with the old batteries then it has to be something like that try the old batteries again if they work straight away you have your answer, connections.

i replaced mine with no problems

 

[voipio]

They should work, unlesss maybe there's a problem with one of the cells. Check the voltages on each cell. Both cells should be prettym much the same if they've been treated similarly.

Another check is that the pips make contact with the +ve terminals. I've had problems in the past with rechargeables not making the +ve connection. Easily sorted with a quick clean with a file and a touch with a soldering iron. Juat enough to melt the solder, but not enough to damage the cell seals.

 

[ytre]

Thank you snooper had to bend the terminals out with a small screwdriver and hey presto

 

[the snooper]

well as BT advertised, its good to talk and now you can

 

[Wedg1e]

They should work, unlesss maybe there's a problem with one of the cells. Check the voltages on each cell. Both cells should be prettym much the same if they've been treated similarly.

Another check is that the pips make contact with the +ve terminals. I've had problems in the past with rechargeables not making the +ve connection. Easily sorted with a quick clean with a file and a touch with a soldering iron. Juat enough to melt the solder, but not enough to damage the cell seals.

A lot of AA and AAA batteries now seem to be made with the (+) contact lower than usual, so in a lot of equipment the battery won't 'reach' the spring terminal. We get it occasionally at work with irate clients claiming stuff we've sold them packed in - JUST when they fit new batteries (invariably cheapies from Asda or Lidl).
I have a multi-cell charger for my AA and AAA collection and the (+) terminals are shrouded, so you can't easily get at them to bend them out. Have to resort to bits of ally foil sometimes

 

[500e]

Just a tip
Clean battery terminals with a lead pencil, this cleans them without damaging any coatings that stop corrosion, soldering is not good as some rechargeable's vent through minute hole in + terminal