All of this solar kits we sell come with a PWM charger as standard. This is the box that turns the solar power into something your battery/ies can handle and charges them correctly.
But there is a better option - MPPT. MPPT chargers typically produce 20% to 30% more charging power from the same panel than a PWM charger (in our experience 20% is realistic). At the bottom of this page is a technical explanation why.
The charger upgrades we offer are:
Above is the 10Amp MPPT charger with built in LCD display. The black LCD on the right is the optional "external/remote LCD" display. You can buy the charger upgrade with or without the remote LCD which shows the same information as the charger's built in display, but with more information on the screen at one time. It also means you can install the charger in a cupboard and flush mount the remote LCD in the side of a cupboard/wall/surface (the LCD is shown in it's surface mounting box, but it can be removed and mounted almost flush). It links to the charger with one slim network cable.
Also available is a 250 Watt version that you will need if you buy a 240 watt solar panel system. It's the same, just larger, and can handle 20 amps.
Above is the Victron 75/15 MPPT charger. What is different about this charger is that there is no LCD display at all. You can access charging information and configure the charger via your smartphone with the supplied app (iOS & Android) using bluetooth. The charger is highly configurable via the app - right down to how the charging cycle works! Note that we now sell the SmartSolar version which has Bluetooth integrated , rather than the separate dongle as shown above.
Note - the Victron 75/15 is a 220w rated charger in its specs, but it can handle two panels at 240w as it can handle 15 amps (the panels will produce 12amps in a pair, in optimum conditions) - but it is on the limit, therfore we supply a 100/20 Victron which can handle 290 watts if you order a dual panel kit. If you bought a 75/15 charger and then added a panel later on down the road, it would run both panels happily.
This charger is a good solution if you want to hide your charger and don't want to cut big holes for an LCD display/control panel. The disadvantage is you can't see your battery voltage or charging status at a glance. You have to open the app on your phone or tablet.
The Epever DuoRacer series (above) is a dual battery MPPT charger. This MPPT solar regulator will charge both your starter battery and your leisure batter/ies. The standard 10A model can handle up to 130 Watts of solar panels. Note it is a special order so adds around 3 days extra to delivery times. We also sell a 30A model that is suitable for twin panel installation and can handle 390Watts.
Additionally, you can add a remote MT11 LCD display panel that repeats the information on the charger screen. It comes with a 1m cable.
An MPPT charger works differently from a PWM charger. Solar panels typically produce 12-20volts. The voltage goes down as the sun diminishes, and as the panel gets hot. To charge a leisure battery the volatge of the charger needs to be more than the voltage of the leisure battery - approx 13volts. This is why solar panels produce up to 20volts, so there is some room to play with. We always recommend MPPT chargers with slimline panels as they priduce a higher voltage, which suits MPPT better - you waste less energy.
When a panel is produces, say, 18 volts, a PWM charger "throws away" the spare 5 volts. With MPPT the charger turns the spare voltage into charging current. The voltage lowers but the amperage increases. The upshot is that, in ideal conditions, an MPPT charger can extract an extra 30% charging power from the same solar panel. Ideal conditions are bright sun and low temperatures - which means winter, or bright but cool days - i.e. frequent British Springs/Autumns.
An MPPT charger is the way to extract every last drop of energy from your solar panel and are particularly recommended for ultra-slim panels.