I specialise in the repair and service of Electrolux and Dometic 3.5 230V Travel Power generators which were popular throughout the ’00s on mainly Beta and Barrus engines.

Update: 20/5/21… Unfortunately due to the age of the units and scarcity of good 2nd hand parts I no longer offer repairs to Powerbox’s. With the move to Lithium systems travel powers are no longer a great solution. With a typical Victron 12/3000/120 MultiPlus max charging is limited to 120A and runing such a high load at tickover can potentially cause engine problems. I have a 200 Amp Bosch 12V alternator conversion which runs at 140A+ continuous output and the external regulator throttles down engine load at tickover. See below for an installation example.

I still carryout troubleshooting work and rebuilds to the engine mounted alternator which is the fault 90% of the time. Most alternator parts are available and I have good stock of the bespoke Dometic/Electrolux items.

Travel Power to High Power 12V Alternator + Alpha Pro Conversion on Nb. Funky Fish

Customer had a Powerbox fault on his ~2006 era 3.5 Travel Power system. http://www.selweb.com looked at the box and judged it uneconomic to repair. I fit a 200 amp Bosch alternator with 55mm freewheeling pulley and adapt it to work with a Mastervolt Alpha Pro III controller. System is setup to work with the Barrus Shire engine with 3.5:1 pulley ratio. At tickover alternator output is reduced by the controller and as engine revs increase full power is gradually unleased. See over 200 amps alternator output at 1200rpm which easily runs all the equipment through a Mastervolt inverter, originally powered by the Travel Power. Alternator temperature is kept in-check by the Alpha Pro’s temp sense control. Engine runs smoother under loads and battery charging is greatly enhanced by the Mastervolt Alpha Pro. My customer is delighted with the new setup and thinks it’s a real improvement over the old Travel Power system.

Travel Power Notes..

  • The vast majority of problems are caused by brush, slipring & connection issues and generally the powerbox’s are reliable. The problem is either alternator/loom or powerbox. If the system is working intermittently almost certainly it’s an alternator or connection issue.
  • The replacement brush box’s for the Bosch alternator have shorter brushes than the original and they wear prematurely. I re-brush them with longer brushes to the original spec – my competitors don’t.
  • It’s a good idea to have a TP alternator serviced from time to time. Rotor bearings can fail which can potentially destroy the expensive alternator with custom stator windings, or bearing can spin in the soft aluminium housing damaging the casing . As a very general rule I recommend 2-3000 hours for the Bosch alternator and slightly longer for the later Iskra unit.
  • When carrying out an oil change service or if the belt has to be re-tensioned always remove the TP belt and check for any roughness or play. If there’s any unusual ticking or whining noises switch off ASAP and check it out. The Bosch alternator is an old design and was never intended to be driven by a poly-V belt and the higher loads they can apply – all the automotive applications run a V belt. It’s very important not to over tension the belts on both types of TP alternator.
  • The jerky motion of a diesel engine particularly with a large crank pulley as fitted to TP installations cause driving forces along the poly V belt in both directions. This causes the belt to bounce, snatch, slip and squeak. Over-tensioning the belt helps to stop this. Fitting a freewheeling alternator pulley (a pulley which only grips & drives in the clockwise direction) generates forces along the belt in the driving direction only and makes the belt run dramatically smoother, increasing grip at a lower tension. The engine also runs smoother and the small (50mm) freewheeling pulley can increase generator output at tickover. Beta have installed freewheeling pulleys as standard to domestic and travel power alternator from around 2011 onwards.
  • Beta used to fit custom aluminium pulleys to Travel Power and domestic alternators. These pulleys are soft and once the poly-v belt profile starts to wear, contact area decreases and wear accelerates. Tell tail symptom is black belt dust around the front of the engine. If you have problems with squealing belts and you think you might be over-tensioning the belt it’s best to fit a freewheeling pulley. The small (~45mm) diameter solid steel TP pulley on some Barrus engines are also susceptible to profile wear. .
  • Fault diagnosis should be made on the boat. Fault’s can be with the wiring looms, connections/terminals, rocker switch, alternator, powerbox or appliances on the boat.
  • The alternator can be tested in-situ on the boat or run up on the bench and no Powerbox is needed. The powerbox is very rarely at fault.
  • The 5 core cable is often overlooked. With oil/fuel/water contamination the insulation breaks down and this can cause serious problems and potentially destroy the Powerbox. If there’s any doubt the cable should be cut back at the alternator end and re-terminated.
  • I carry new original spec quality 5 core tinned generator cable and the original spec uninsulated spade terminals for the early units (NOT the cheap SY control cable or brass or blue insulated terminals used by other repairers). As a safety point the outer braid of the 5 core loom should be clamped and connected (grounded) at the alternator and powerbox end.