Should The Bright Way Switch Mode Battery Charger BRW77FR Go To Zero ohms When Not Plugged In?
Updated 11/04/2025 | Published 07/31/2025 >
Question:
My dump trailer has to spend a lot of time away from a 120 volt plug in. If it’s more than a month, unit not used but starting with a fully charged battery, the battery will be flat. Ohmed out the two leads on the charger and there are 6.6k ohms. Is this unit supposed to go to zero ohms when not plugged in? This is a class2 battery charger. 5 amp fully automatic for 12 volt battery.
asked by: Chris R
Expert Reply:
Hi Chris!
The Bright Way Switch Mode Battery Charger for Hydraulic Lift and Dump Trailers - 12V - 10 Ah # BRW49FR incorporates circuitry that uses very small output pulses to detect if a load (like a battery) is connected. This allows it to "turn on" when a device is plugged in and minimize power consumption when idle. The 6.6 ohms likely reflects the resistance of this internal detection circuitry, not a fault in the charger. Measuring resistance also helps chargers determine the appropriate voltage and current to deliver, preventing overcharging or damage to the battery.
Hope this was helpful and please let me know if you have further questions!
Out of curiosity, why does your dump trailer spend so much time idle?
Product Page this Question was Asked From
Bright Way 12V Onboard Battery Charger for Hydraulic Dump Trailers AC to DC - 12V - 10 Ah
- Battery Charger
- Battery Charger
- Dump Trailer
- Trailer
- 12V
- Charges and Maintains
- Lead Acid
- Shore Power to Auxiliary Battery
- Smart Charge
- Bright Way
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Chris R.
8/5/2025
It is used on the farm and stays in or at a barn with no electricity.