I have an android, and my phone's battery seems to run down a lot quicker with my new sim. For example, on idle (with wifi, 3g switched off), the battery decreases by around 5% overnight, whereas with my old sim, my phone could last through the night without dropping a single percentage of battery. Don't know if this is relevant, but I have noticed that with my new sim, the 3G internet coverage/speed is a lot poorer than my old sim, but their phone reception seems near equal.

Does anyone know of this problem? I've never heard that a change of sim card can affect battery life

my old sim is giffgaff, and my new sim is ovivo

Yes it's possible.
Giffgaff runs on o2 and Ovivo is vodafone so the phone could be hunting a signal more depending on the distance to the nearest vodafone mast which in turn will affect battery life.

is it possible to check where exactly my nearest o2 and vodafone masts are?

I'm unsure if this is the problem because I live in busy city centre, so surely there can't be that much of a difference between these two network providers in terms of phone coverage, to affect my phone's battery life by this much. Although my ovivo 3g signal is a lot worse, isn't that irrelevant because as I've said, I have my 3g data turned off when my phone's on idle. And in terms of the phone coverage with making calls and text, they're both almost as good as each other.


do you think I should try putting my phone in airplane mode?

The lower signal level will mean that when in use, your phone will have to transmit at a higher power to reach the new serving site, so this will impact your battery life. Even when your phone is idle it does update its location periodically to the network (and by location that's network location not actual location, which is usually based on network controller areas). You might also be really unlucky and now be on a network location border, which can cause the phone to do this update even more often as it moves about your house.

If you put it in airplane mode then this will disable the radio and impact of this, so would restore your previous battery life (and should give an even longer life). If it's an Android phone, you can check your battery use by application under settings->battery, e.g. Mine currently says 9% due to Mobile standby, which are these background, idle mode network updates.

Put your phone in 2G only mode.

An update here. I've put my phone into airplane mode (with my new sim on), and I've noticed that the battery drain has gone away. So is it certain that the problem is due to the sim's network? that the nearest vodafone mast really is too far away from me?

Yes. That's the issue. Put it in 2G only mode

how do I do that? and why would this make a difference?

I assume you have an android phone?

Go to Settings> More > Mobile networks > Network mode > change from WCDMA to GSM.

2G uses less battery.
Also you have a weak 3G signal so the phone is constantly searching for a stronger 3G signal. This cause battery drain. On 2G it won't do this if you have a good 2G signal.

I tried this, the same battery drain occurs. I'm at the city centre, do you think vodafone's reception would be this bad in such a busy area? (using ovivo, but apparently they're on vodafone's network)

I've noticed this as well:

When I put it on 'WCDMA only', I can't get any signal at all. My signal bar is down to nothing. Whereas before when I had it on 'GSM only' or '4G (preferred)/WCDMA/GSM', the signal bar was showing at max or near to max. But I've just realized this occurs when I'm inside. With my phone still set at 'WCDMA only', I stuck my phone outside my window, and the signal strength went to 3-4 bars out of 4. And as I took the phone back inside, the signal we back to nothing or very weak.

bump, any ideas?