Can an RV MPPT solar charge controller work with 12V, 24V, 48V and 96V banks?
6 min read
Across the family, yes, and each model is published for particular bank voltages rather than for all of them: 12V and 24V on the 20A and 30A models, 48V on the 40A and 60A models, and 96V on the 80A and 100A models. What changes with the bank voltage is the panel side: the published maximum open-circuit voltage and the maximum panel power both rise, which is why the same controller current can accept far more solar on a higher-voltage bank.
Why the bank voltage changes everything
A charge controller is rated by output current, and power is current multiplied by voltage. The same 40A of charging current is 480W into a 12V bank and 1920W into a 48V bank, so a higher-voltage bank lets a controller of the same current rating pass far more solar. That is the real reason van systems move up to 24V or 48V, and it is why the published panel power limits differ so much between models.
What our range publishes
| Models | Battery voltage | Maximum panel open-circuit voltage | Maximum panel power |
|---|---|---|---|
| 20A | 12V | 80V | 240W |
| 30A | 24V | 80V–105V | 720W |
| 40A / 60A | 48V | 180V | 1920W / 2880W |
| 80A | 96V | 280V | 9600W |
| 100A | 96V | Not listed for this bank voltage | Not listed |
The minimum working battery voltage
- 12V and 24V models: 10.5V or above, published as the minimum working battery voltage.
- 48V and 96V models: 40.5V or above.
- That figure is where the controller starts working and where it stops, so a deeply discharged bank on a higher-voltage system has further to come back before the controller will help.
Choosing between them
- Start from the bank, not the array. A 12V bank cannot use the headroom a 96V model offers, and a 48V bank will not accept a 12V model's charging profile.
- Then match the array to the published panel power limit for that bank voltage, because that is the figure the model is rated for.
- Then check the string's open-circuit voltage against the ceiling for your bank voltage, remembering that panel voltage rises in the cold.
- If you are planning to move the system to a higher bank voltage later, say so when you ask us: the note on the published table exists because the answer depends on the configuration.
Frequently asked questions
- Will one controller work on both a 12V and a 24V bank?
- The 20A and 30A models publish 12V and 24V as their battery voltages, with the same minimum working battery voltage of 10.5V. The panel ceiling differs between those two models, so the array has to suit the model rather than the other way round.
- Can I use a 48V controller on a 12V bank?
- No. The 48V models publish a battery input voltage of 48V and a minimum working battery voltage of 40.5V, so a 12V bank is outside what they are published to charge.
- Does a higher bank voltage mean more solar power?
- For the same controller current, yes, and the published panel power limits show it: 480W at 12V against 1920W at 48V on the same 40A. The array you can connect is limited by the model's published figures for your bank voltage.
- Why does the 100A model have no 48V or 96V panel voltage listed?
- The published table leaves those cells blank with a note that the ratings are configuration-dependent and should be confirmed with us. Rather than guess, ask us for the model you have in mind and we will give you the figure for that configuration.
