Lithium (LiFePo4) batteries are a big deal and offer huge benefits for narrowboat life off-grid. Generally boaters don’t realise or appreciate just how good a well designed Lithium system actually is. It’s hard to explain or describe without showing a setup being used but it totally transforms power onboard.

This page ties in with my ‘Alternator Controller’ page to lithium proof and maximise alternator charging.

I’m happy installing a complete system from scratch, working on specific components of a system, or make improvements and additions to an existing system (such as a alternator/charging upgrade or battery monitoring and control).

Pretty much all factory installed engine alternator setups haven’t been designed with lithium batteries in mind. I’ve developed upgrade kits for some of the most popular engines to realise the awesome charging properties of a lithium setup.

  • For Isuzu Canaline engines a complete kit using a Bosch 200 amp alternator with 6PK Poly V crank pulley conversion.
  • For some Barrus Shire 40 & 45 a 200 amp Bosch upgrade kit with a 6PK poly V crank pulley conversion.
  • For the Beta 43, 50 & 1903 a 12V 200 amp or 24V 120 amp Mahle (Iskra) with custom freewheeling pulley.
  • For the 3.5 Travel Power there’s a 12V 200 Amp Bosch, or 24V 110 amp Mahle alternator conversion available.
  • On a new-build it’s so important to pick the right engine even if there’s no plan to install lithium batteries at that stage. Some engines are far better suited than others. Long term it will make switching to Lithium far easier and cheaper. At this point it’s well worth considering a 24 volt system.

The incredible limitless recharge property of Lithiums mean you have to ‘lithium-proof’ the alternator. People try to achieve this in different ways. I specialise in installing an alternator controller and (IME) this is by far the best approach – any other method is just clumsy and compromised in comparison. I carry the Mastervolt Alpha Pro and along with an alternator upgrade kit supply and fit as a complete package. You don’t need the expensive Balmar or Mastervolt alternator and when running a poly V setup I’d advice against them due to inability to run a freewheel-clutch alternator pulley – this makes for a smoother power transfer reliably handling continuous high loads. I can modify all alternators to work with Mastervolt, Wakespeed & Balmar controllers. If you already have a Beta 43, later Barrus, or Engines Plus Canaline engine with a poly V setup and 150A + alternator you’re along way towards a great lithium proof setup.

Key points that alternator controllers offer in respect to charging lithium:

  • Alternator temperature sensing: Damage caused by the alternator overheating is a real risk without any temp sensing. This is an important point as engine bay air temperatures can become incredibly high particularly in warmer weather and limiting current alone isn’t always enough.
  • They enable an alternator to be easily shut down – either with an engine panel mounted switch, or automatically with a lithium BMS or a Victron BMV Battery Monitor. This means you are not disconnecting the output load which risks destroying the alternator. Doing this safely is complicated in itself requiring a dump load.
  • Absorption voltage can be adjusted to a safe, conservative level – so you generally don’t need to rely on a Battery Monitor or BMS completely disconnecting and disabling charging as is done with other methods.
  • They can de-rate the alternator to suit maximum recharge current rating (C rating) of the lithium (or lead acid) battery.
  • Some controllers have a ‘small engine’ feature where output is throttled back at low engine speeds to improve engine driveability but at a selected engine speed full power (or an adjustable percentage of full output) is unleashed. This is an awesome feature and fully enables the fast recharge ability of Lithium while protecting the engine and alternator.
  • Small engine mode is useful for the 35-45hp engines typically seen in narrowboats where large alternator loads can cause serious engine running problems at low engine speeds particularly in-gear tickover. Raising tickover isn’t a good way to deal with it.
  • Small engine function is useful (IME vital) for Beta 43 & Beta 50 engines where uncontrolled high alternator loads below 1200 rpm increase the risk of the crank pulley issues associated with these engines.

For narrowboats already with a 3.5 Travel Power and a Victron 12/3000/120 Multiplus it’s possible to build a great simple setup. The Multicontrol AC current control should be dialled to put a limit on crank loads at tickover. For the Beta 43/50 in particular it’s important to have a sensible limit on crank load at low engine speeds & high alternator loads should be disabled while using the Travel Power.

I have the equipment to program and setup all of the Victron and Mastervolt kit.

Any queries or if you need this type of work doing please call Ed 07922 163072.