Portable Battery Chargers - (DIY vs Buy)

So this fall I will be traveling to Alaska, I know cell coverage up there is available but not always the most reliable even in the populated areas so I will be taking at least one set of radios up there with me for the trip.

At the moment I am considering taking 2 Motorola UHF HT750’s. They are the best suited for the environment of the units currently available to me. The downside is having to charge the batteries. I know the standard rapid charger requires an 18 volt input to charge these units so I am considering either buying or building a portable power source to have as a backup should I need to charge these in the field or provide power for phones / tablets.

So the way I see it there is a few options. Either I get a 12 volt rig that I can then plug a car 12v to AC adapter into or I custom build something that has the ability to output different voltages.

Going the 12v method means I loose a lot of energy going from one medium (12v dc to 120v AC back to 18v dc) and may need a larger battery to be worth it. But custom making the battery/charging station would take more time and perhaps money, but may result in the best size/least amount of equipment.

Any one have any thoughts or taken on a project like this?

best wishes and do not forget to post the pics of the tour and battery station

There are chargers on the market that offer both AC and DC options. Here’s an example of a 3 bank charger, and a 6 bank charger..
These are self switching smart chargers.

Thanks Kyle, that’s actually a really good solution. Perhaps a bit expensive for the current use case but I never knew someone made one that has the ability to do the different batteries. Does it do different voltages?

These chargers are 110/240V self switching for international use or 12V in DC, and while using both power supplies simultaneously, the charger will choose the AC power.
I’m not sure how many radios you are taking but it may be more affordable to take an AC and a DC single Charger.
Typical charge time is 2-3 hours.

Thanks Kyle, I was referring to the batteries that the charger can charge. So for example I have an HT750 whose battery produces 7.4V and an CLS1100 that produces 4.5v. As a guess I would believe that the two radios need different charging voltages to correctly charge the batteries (ie: The charger would need to produce a different charge voltage for each radio) is that possible with this system?