charging a nexstar evolution in the middle of a field

[NicolaTerry]

I'm thinking about buying a nexstar evolution 8. I want to use it at a 5 night star camp. 

With no mains power available I'm trying to work out how to recharge the lithium battery.

My current thinking is a 12v leisure battery (about 110Ah) and a dc-dc converter.

Does anybody have any experience of this problem or can offer some advice

Thanks, Nikki

[Davey-T]

Lithium batteries should only be charged with the supplied mains charger, if you want to use a normal 12 volt battery you'll need a little inverter, about £30.00.

Dave

[NicolaTerry]

I've heard that cheap inverters can damage modern chargers and that an expensive (£2-300) pure sine wave inverter was needed.

I was hoping that the constant 15v output from a dc-dc converter would be about the same as the output from a mains charger but I can't find  any specs for the celestron charger.

[Cosmic Geoff]

If the Evolution can be run from an external +12v supply, the obvious answer is to have an external power pack on hand, and recharge the internal battery at home with the power supply provided.   Lithium batteries should always be recharged with the  designated charger. 

You could in theory use a large +12v battery to run an inverter to run the lithium charger but this seems inelegant.

My LiFePO powerpack is recharged with a +16v charger which cannot be used for anything else.

EDIT: A lot of telescope questions can be resolved by downloading the relevant manual and reading it.

This one indicates that the mount can run from an external +12v supply, and the designated charger also delivers +12v via the same port.