"But it should be charging while I drive..."

In theory, yes. In reality, many caravans barely gain charge while towing.

The biggest misconception

People assume the tow vehicle alternator will:

• Fully charge the caravan battery
• Do it quickly
• Do it reliably

Modern vehicles simply don’t work that way.

Common reasons charging fails

• Voltage drop over long cable runs
• Smart alternators reducing output
• Undersized wiring
• No proper DC-DC charging system

The result? Your battery looks like it’s charging - but never reaches full capacity.

Why this matters off-road

Partial charging:

• Reduces usable capacity
• Shortens battery lifespan
• Causes confusion when solar "doesn’t keep up"

What proper towing charge looks like

• Dedicated DC-DC charger
• Correct cable sizing
• Charging profiles matched to battery chemistry

Anything less is compromise.

The takeaway

If your caravan "never quite lasts as long as expected", charging while towing is often the missing link.