Monday, 18 March 2013


If you have a smartphone and your UK network provider is Three then you might be interested in the following. 

Three has been blocking some websites I’ve attempted to visit.  No….. not Adult sites!  Some fairly innocuous sites were being blocked.  After some experimenting I discovered the situation improved if I amended the APN in the phone settings from “” to “3internet”.  Next I discovered if I downloaded and installed Opera Mini as the phone internet browser it appears to circumvent the site blocking.

We’ve now had two nights of heavy rainfall and the River Kennet is back up.  Actually even the water in the canal has risen and as a consequence we no longer have a list.  Two of the hire boats returned today with some very miserable and wet boaters exposed on the stern.  The only place we will be going in the next few days is to the local water point!

Nick Norman left a comment on yesterday’s post pointing out the ‘Bulk’ charging of a battery to 80% is a very approximate figure.  He is correct, and there are many variables in calculating the duration of the Bulk charge.  With much I’ve written its either been very generalised or it’s specific to our particular equipment.

Part 5 – Battery Equalization

If a lead acid battery isn’t fully recharged on a regular basis or used unfrequently, two things can occur which may degrade battery capacity. The first is there may be a build up of sulphate crystals on the lead plates which then act as an insulator preventing the battery reaching 100% capacity during recharging. The second is stratification of the electrolyte. This means the electrolyte isn’t an even consistency which has an adverse impact on the ability to fully recharge the battery.

Equalizing the batteries is a process where a higher than normal voltage is put into the cells of the battery to ‘stir-up’ and re-mix the electrolyte in an effort to ensure all the cells are “equal”. The process can also remove some of the crystallization that may have occurred on the lead plates. A little like water blasting all the “crud” and minerals that have built up on the hull below the waterline.

It’s important the correct level of voltage is used during the equalizing process. Different battery manufacturers specify different voltages. Our Rolls manual states the equalizing voltage should be between 15.8V – 16.04V. The Sterling PDAR ensures our alternators produce a maximum of 14.8V but this appears to be insufficient for the equalizing of our batteries. The Victron combi inverter/charger is able to produce an “Equalizing” cycle but this is set at 15.2V. Again this is a lower voltage than specified in the Rolls battery manual. 

When we were living on Peter & Margaret’s boat (nb Kelly-Louise blog) Peter pointed out he used two CTek 240v battery chargers connected to shore-power to maintain the boat batteries. This has given me an idea and I started looking for a mains battery charger with the required characteristics to complete our equalizing charge. The CTek MXS 5.0 has a “Recon” (reconditioning) and a “Desulphation” cycle. Both are at 15.8V which is the minimum specified equalizing voltage for our Rolls batteries.  The charge output of the CTek (not the voltage) is too low to recharge the batteries.  However it’s the voltage during the Equalization process that’s the important factor (pressure of the water blaster rather than the volume of water).  So a small CTek charger would probably be able to produce the equalizing charge but not recharge the domestic battery bank.  However it would recharge the start and bow thruster batteries.

Our Rolls manual also states the batteries should be equalized every 30 days to 6 months depending upon use and the ability to be regularly fully recharged.

Both the Victron inverter/charger and the Ctek charger require a 240v power source. As continuous cruisers the only way for us to have an independent 240V power source is to have a suitable generator. So if we are going to effectively maintain the domestic battery bank we probably need a generator. If we have a generator then we might as well use it weekly to ensure the battery bank is fully recharged using the Victron. The latter has the ability to indicate when each stage of recharging is occurring (Bulk, Absorption & Float). This is something our Smartgauge cannot do!  We should also consider purchasing a CTek charger (or similar) so we can complete the required infrequent equalization charge. Another advantage in having a generator is it would also give us a secondary source of electricity should we have an engine problem.

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