Power supply for off-road and expedition vehicles – all components at a glance
Self-sufficiency in a vehicle is a calculation, not a question of brand. It starts with your daily consumption in ampere-hours: cool box, parking heater, lights, water pump, laptop, coffee machine. This gives you the usable battery capacity you need – and how much you have to recharge each day. In a vehicle you have three sources for recharging: the alternator while driving, solar while parked, and shore power or a generator when neither is enough. In this category you will find the components for all three routes – batteries, chargers, charge boosters, vehicle alternators, combi inverters, charge distribution and solar regulators. philippi develops and manufactures some of these components in its own factory in Germany and supplements them with selected brands.
Batteries The service battery determines how long you can manage without recharging. What matters is not the printed capacity but the usable one: LiFePO4 batteries such as the SB 12V210E NOMIA from SuperB deliver their 210 Ah almost completely and, according to the manufacturer, replace around 500 Ah of lead-acid – at a weight of 23 kg. That is the real lever in a vehicle, because payload and space are limited. Alongside the SuperB range (NOMADA, EPSILON, NOMIA) you will find BullTron batteries for 12 V and 24 V, the MLI Ultra from Mastervolt and, with the LB48/105, a 48 V battery for larger expedition bodies. Pay attention to the permitted temperature range: lithium may usually only be charged above 0 °C, while the NOMIA can be discharged down to –20 °C. If you travel in winter, the battery box has to be positioned or heated accordingly.
Charge boosters In a vehicle the alternator is the most important charging source – but rarely a good one. Modern vehicles reduce the alternator voltage depending on demand, and there are voltage peaks on overrun and voltage drop along long cables to the habitation area. A charge booster such as the DCB 12V turns this into a clean three-stage charging profile and fully charges the leisure battery even on short legs. The range runs from the DCB 12V with 12 V input and 60 A charging current through the DCB 24V (12 V to 24 V, 30 A) to the DCE 36V and DCE 48V – so you can charge a higher-voltage system without fitting a second alternator. Practical in a vehicle: soft start relieves the drive belt when pulling away, operation is fanless and therefore insensitive to dust, and the temperature range is –20 °C to +60 °C at over 96 % efficiency. For voltage conversion without a charging function – for example a 24 V system to 12 V loads – there are the DD and PV converters from alfatronix.
Battery chargers For shore power at the campsite or in the workshop, philippi builds the ACE series in Germany: ACE 12/30, ACE 12/44, ACE 12/64 and the high-power ACE 12/90 for 12 V, and ACE 24/25 and ACE 24/30 for 24 V. They charge up to three battery groups at once – for example leisure, starter and a third bank –, work without a fan using a heat sink in the housing base and accept 90–265 V AC without loss of output, which matters when travelling with weak grids. Seven charging programs cover flooded, lead-calcium, GEL, AGM and lithium batteries; the ACE 12/30 is designed for 120–250 Ah. Remote displays such as the F-ACE and FAL bring the readings into the cab. Also in the range: the ChargeMaster Plus from Mastervolt, the BatteryLink BS 7607 from Blue Sea Systems and high-power 24 V units from cristec.
Vehicle alternators If you drive a lot and stand still little, the cheapest energy comes from the engine. High-output alternators from Balmar are available in 12 V with 100 A, 120 A and 170 A (XT series, single or dual foot) and in 24 V with 70 A and 140 A. Regulation is decisive: external regulators such as the MC 618 (12 V), MC 624 (24 V) and ARS-5 provide a multi-stage profile instead of a constant voltage, and the CFII balancing regulator supplies a second bank. Because belt load and heat determine service life in a vehicle, belt tensioners (Belt Buddy), adjustment arm and matching pulley kits are part of the planning. From Mastervolt come the Alpha Pro III and the Alpha 24/150 MB. If driving and solar are not enough, the Panda 5000i generators from Fischer Panda supply power independently of the engine.
Combi inverters 230 V in a vehicle comes either from a pure inverter or from a combi unit that combines inverter, charger and transfer switch. The Studer XTM and XTH combi inverters cover 1500 to 3500 VA for 12 V and 24 V systems, charge at up to 100 A and, with Smart-Boost, also start loads with high inrush current by adding battery power to shore power. Where only inverting is needed, the sine-wave units of the AJ series from AJ 275 to AJ 2100 / AJ 2400 are enough; from Mastervolt there are the Mass Sine and Mass Combi Ultra. Operation and monitoring are via the RCC-02 or RCC-03, and the RCM 10 add-on module reduces standby consumption – a real factor in a vehicle, because quiescent current works against battery capacity over days.
Charge distribution So that starter and leisure batteries do not drain each other, charge distribution separates and connects them automatically. For this, philippi builds the VHR 200 isolating relay, the 40 A and 70 A automotive relays, the BLA charge equaliser as well as cable sets and the ACE-T cables for the P-Bus connection. From Blue Sea Systems come isolating relays such as the ACR 12/24, the ML 500A 12V ACR with manual override for emergencies, the ACR Mini and the complete Add-A-Battery kit for easy second-battery retrofits. The Studer RCE charge distributor and the Mastervolt Mac Plus complete the range.
Solar regulators Solar is the source for long stays – but in a vehicle it is limited by roof area. The Studer VT MPPT solar charge controller gets the most out of existing panels and is available as VT 40, VT 65 and VT 80 with 40, 65 and 80 A charging current for 12, 24 and 48 V batteries, with IP 54 protection and under 1 W reverse current in night mode. The Solar ChargeMaster from Mastervolt is the alternative. How much you really harvest and use is shown by a battery monitor such as the philippi BLS – without measurement, every self-sufficiency calculation remains an estimate.
Not sure how consumption, battery capacity and charging sources fit together in your vehicle? Our team will advise you personally – from the first consumption calculation to the finished installation.
Frequently asked questions about power supply in vehicles
Do I need a charge booster?
In most newer vehicles, yes. As soon as the alternator is regulated according to demand, the charging voltage drops after a short time, and the leisure battery never gets full through a simple isolating relay. A charge booster such as the DCB 12V creates its own three-stage charging profile from this and also compensates for the voltage drop along long cables to the habitation area.
How big does my leisure battery need to be?
First add up the daily consumption of all loads in ampere-hours and multiply it by the number of days you want to bridge without recharging. With LiFePO4 you can count on almost the full capacity, with lead batteries only on about half. The Academy article Calculating battery capacity shows how to do this step by step.
Is solar alone enough for self-sufficiency in a vehicle?
Usually not. The usable roof area is limited, and the yield varies greatly with season, location and shading. Solar covers the base load while parked well, while driving current via a charge booster recharges the bulk; a shore power charger or a generator such as the Panda 5000i remains the fallback.
Lithium or lead in an expedition vehicle?
Lithium provides much more usable capacity per kilogram and per litre of space, which is decisive with limited payload. The price is the temperature limit: LiFePO4 may typically only be charged above 0 °C. If you travel in winter, you have to choose the battery location accordingly or heat it. More on this in the Academy article LiFePO4 or AGM.
Do the devices work in 12 V and 24 V vehicles?
Yes. The ACE chargers are available for 12 V and 24 V, as are the XTM and XTH combi inverters, and the VT solar charge controller can be configured for 12, 24 and 48 V. For vehicles with a 24 V system and 12 V loads there are also voltage converters, such as the DD and PV converters from alfatronix.
How do I monitor the system in operation?
With a battery monitor such as the BLS, which shows voltage, current and state of charge. The philippi ACE chargers can be integrated into P-Bus system monitoring via the ACE-T cables, and Studer units are operated and monitored via the RCC-02 and RCC-03 remote controls. This lets you see yield and consumption in one place.
