Thunder TDR02020 20A DC-DC Charger With MPPT Solar Regulator

Quick answer

The Thunder TDR02020 charges a 12V auxiliary battery at up to 20A from the vehicle and has an MPPT solar regulator built in.

Thunder maps the charge for GEL, AGM and standard lead acid batteries from 18 to 250Ah. Lithium is excluded.

Problems it solves

• Computer controlled alternators that drop voltage. The manual says it works with them, with the negative taken to chassis on variable voltage systems.
• A separate solar regulator in the canopy. Up to 300W of panels at 13V to 25V wire straight into the solar terminal.
• Not knowing what the charger is doing. The display shows the charge stage in 10% steps, plus solar, reverse polarity and faulty battery lights.

Specifications

• Output: 20A, 12V batteries only
• Vehicle input: 12.2V to 17V; shuts off above 17V and needs a reset
• Charge voltage: 13.1V to 15.2V
• Float voltage: 13.8V
• Solar input: 13V to 25V, 300W maximum
• Charging: 8 stage from the vehicle, 3 stage from solar
• Battery size: 18 to 250Ah
• Battery types: GEL, AGM, standard lead acid
• Fusing: 30A minimum on input and output, breakers not supplied
• Standby draw: 3mA
• Operating temperature: 0 to 60C, current derates above 60C

Fitment and compatibility

12V auxiliary batteries from 18 to 250Ah in GEL, AGM or standard lead acid. Mount it in a dry spot inside the vehicle or van; the manual says it is not for outdoor use.

Install notes

Fit 30A minimum circuit breakers, not supplied, close to each battery. Size the twin core cable by run: 6mm up to 1 metre, 8 B&S from 1 to 5 metres, 6 B&S beyond 5 metres. A caravan install needs a heavy duty plug such as a 50A Anderson at the tow vehicle.

Warranty

12 month Thunder warranty against defects in materials and workmanship. This comes with the manufacturer's warranty through the Australian distributor. See the manufacturer's terms for details, plus our guarantees under the Australian Consumer Law.

FAQ about the TDR02020

Does the TDR02020 suit a lithium auxiliary battery?

No. Thunder covers GEL, AGM and standard lead acid only; lithium is excluded.

What cable size do I wire to the TDR02020 for a 4 metre run?

Thunder specifies 8 B&S twin core for runs between 1 and 5 metres. Size the twin core cable by run: 6mm up to 1 metre, 8 B&S from 1 to 5 metres, 6 B&S beyond 5 metres.

How much solar can the TDR02020 take before it is damaged?

300W at 13V to 25V. The manual warns that going past 300W will damage the charger. Up to 300W of panels at 13V to 25V wire straight into the solar terminal.

Also worth a look: Dual Battery Chargers and Dual Battery Accessories.