Purchasing the right solar charge controller is an important decision for your power system. The right choice will be flexible and grow as you add solar panels and other components. As I mentioned in a previous post about MPPT charging, this is the most flexible choice.
I’ve looked over two popular MPPT charge controllers from Outback and Xantrex. Next month I think I’ll select the Xantrex XW MPPT 60 amp controller. Yes it costs more, but it will produce slightly more power from the exact same solar panel array. Here are my reasons for the MPPT style choice, and for the Xantrex unit:
- Flexible input voltage. This gives me a chance to re-wire my panels into a higher voltage configuration. Now instead of 12V, we can have 20-60Vdc and have even less power loss through the wiring from the array. (more power reason 1: less power lost in wires)
- Efficient power conversion with the Maximum Power Point Transfer technology. The Xantrex unit does not disconnect the array to run its MPPT sweep, so it can respond quickly to passing clouds.
- Ability to use newer panels. We won’t have to throw away extra power from newer large panels because the array voltage is too low.
- Flexible future battery bank voltage. I’ll still wire up the battery bank for 12V because I’m not changing the inverters yet. However, when I do we can reconfigure the battery bank to a higher voltage like 24 – 48 volts and still charge the batteries with the new charger
One thing that you may notice when you read the Xantrex XW MPPT charge controller manual is that this baby has plenty of features. So many that the initial read can be intimidating. Don’t worry, I’m sure we’ll go through the highlights of setting it up.
As I looked it over, the unit has a “boost” mode for charging. Thats really good news for off grid use with lead acid deep cycle batteries. It does a mini equalization charge each time it goes into the lighter absorption mode charging. This 1 hour “pulse” as it were helps prevent sulfation of the batteries in off grid use.
What do you think? Will the MPPT charger deliver on what I’m hoping? Share your thoughts and experience below in the comments!