How the hell do I post an item with a battery out of this country? No courier will touch me.

DPD, GLS or ups standard.

All will take batteries.

It's an international Air restriction. So "couriers" or postal services that use aircraft to transport packages will not take them.

DPD GLS and ups standard use sea/road services.

UPS, DHL and FedEx will all take batteries on their express air services also as they use cargo aircraft. The restriction is for regular passenger flights which An Post would normally use. There are some limitations but any standard consumer electronics batteries should not fall under this.

What couriers did you try?

I remember something about your typical "battery" which would be in most consumer electronics, not technically being a battery, but rather a cell and not having to declare there is a battery in the package in this case, but I think it's a grey area so best to be transparent with the shipper.

You can try https://www.parceldirect.ie/

I contacted them before about it and they sent me a battery sticker I had to print out and put on the package, didn't cost any extra.

UPS will take batteries and are reasonably priced. So will DHL and FedEx but they are very expensive.

Also I wouldn't take much notice of Parcel2Go's prohibited items list. Their list is far more restrictive than the couriers' actual prohibited items lists. But bear in mind you will not be insured if you use Parcel2Go to send a restricted item.