>>> would this be a case of abh as no weapons were used?
The level of assault charge depends
solely upon the level of injuries sustained by the victim.
e.g:
No injuries (or very minor injuries) = Common Assault
Injuries requiring a few stitches or minor fractures, such as a broken finger = ABH
More serious injuries, such a fractured jaw or skull = GBH
(GBH can then have 'with intent' added to it if there is evidence that the offender intended to cause such serious injuries)
As you've not given us any idea of the level of injuries sustained by the victim, nobody here can know what type of charge your friend might be facing. It might only be ABH but it could be GBH (or even 'GBH with intent')
The limits on detention in police custody are shown here:
https://www.gov.uk/arrested-your-rights/how-long-you-can-be-held-in-custody
Once charged,the police have to release an (alleged) offender on bail unless there are specific reasons for not doing so. (e.g. because they consider that he might commit further offences while on bail, for his own safety or simply because of the seriousness of the offence with which he's been charged)).
So there's not really enough for us to go on. However I suspect that he's been charged with a serious offence (such as GBH) and then refused bail. It will then be up to a court to decide whether to overturn that refusal or to remand him in custody.