Split-charge installation: VSR or DC-to-DC
A split-charge system uses the vehicle alternator to charge the leisure battery while the engine is running. JRGMTS installs both voltage-sensitive relay (VSR) systems and DC-to-DC chargers because the best solution depends on the vehicle and battery.
What is a VSR?
A VSR watches starter-battery voltage. When the alternator raises voltage above its threshold, it connects the batteries so charge can flow; when voltage falls, it disconnects them. It can be a good solution on suitable vehicles with traditional charging systems.
What is a DC-to-DC charger?
It takes power from the vehicle electrical system and actively controls the voltage and current delivered to the leisure battery.
Why smart alternators change the answer
Many newer vehicles vary alternator output. A simple VSR may not see a stable high voltage for long enough, so a compatible DC-to-DC charger is often more suitable.
What about lithium?
Lithium batteries can accept high current and need a suitable charging profile. A correctly specified DC-to-DC charger can control alternator demand and charge profile.
We install both
We do not treat DC-to-DC as automatically better for every vehicle. If a VSR is technically suitable and meets the need, we can install one.
Frequently asked questions
Is DC-to-DC always better?
No. A VSR can still be sensible on a suitable vehicle.
Do smart alternators need DC-to-DC?
They often benefit from it, but the actual vehicle should be checked.
Can you upgrade a VSR system?
Yes, subject to existing cabling, fusing and battery suitability.