I think every battery expert in the country would say that battery damage had already occurred at 11v, never mind 9.0v!!! Part of the problem is that so much information still abounds from the days when batteries had a resting voltage nearer 12.0v when a 1 volt range down to 11v was 'normal'. Yes 14.4v will give the best compromise between fast charging without overcharging with the resultant internal corrosion. Using a 13.2v float charge rate will protect the battery but may also reduce the efficiency of the system enormously, so not sure that is the best option? Conventional wet acid/flooded Starter batteries in Cars have previously had an average 9 year life. Fitting double the cost AGM's with claims of more than double the life should mean they last 20 years.

Big names like Zig, Bonus Systems, etc have never had a high technology mains charger, just low technology, 1990's style, fixed 13.5 voltage 'charger' which are little more than a power supply.. I understand that Solar works for you, but maybe our new enquirer only uses the vehicle to Ski during the Winter months, a time during which he also needs three times as much power for heating, yet will get only about 5Ah a day out of a 100watt panel. Always take care and follow the correct health and safety guidelines to protect yourself from serious injuries from fire, explosions or leaking acid.When a Motorhome can be sat on a Dealers forecourt for many months, that is a big annual cost in replacement wet batteries and subsequent damage to the charging systems. I suspect it works like most of the others in that it has an x hour 'timer' during which time it charges at 14.4v before dropping down to 13.8v float where the bulk of the charging will take place. In which case the time it takes to do that will also depend a lot on the power of the installation, if it is only an 80w Solar panel, it could take quite a while for the charge to make an impact on a discharged battery bank, so it could vary a lot with different set-ups and discharges. Explosion of the battery or fire is also not unknown with AGM batteries, which are more prone to Thermal Runaway than other Lead batteries. I'm just a novice when it comes to the topic of batteries but the whole NCC system seems a bit wonky to me.

We were recently challenged on this statistic by a big battery retailer who stated all Caravan/motorhome chargers now made in the last 10 years are all "Smart and powerful delivering a range of voltage settings".

Constant Current Chargers

AGM batteries typically require a 14.8v charging rate for maximum performance and life, when almost 50% of all the UK Caravans on the roads have a 13.5v/13.8v charger. If this is true, dropping the float down from to 13.8v to 13.2v will hamper charging significantly. B. Never boost-charge any battery that is below 11.00 Volts as it will be too sulphated to accept a charge; scrap the battery or charge normally.

In my experience the Voltage control of Solar regulators is too course. Even when the electronics is accurate, and they are often way out in real operation plus the limits are inappropriate.Victron 230v Mains chargers have two Float voltages, the normal short term 13.8v Float and a more protective, long term 'permanent' Float of about 13.2v, but never seen this mentioned on Victron Solar regulators so don't know if it applies to these. When fitting the charger to the battery, connect the positive lead to the positive terminal and the negative lead to the negative terminal. data-parent="#accordion-3">

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