Regulating 12v power when battery charging....

[Lorin]

Usual caveat applies here about asking thick questions and all

When the leisure batteries are on charge, am I right in thinking that the voltage feeding the 12v sockets coming off the batteries will also be higher than 12v (i.e. will be the same as the charger is putting in)? Seeing as I have a Sterling B2B charger, that would mean the sockets may be fed up to 14.8v when the battery is being charged.

Could this damage any/all of the 12v appliances that are plugged in?

If so, is there some gadget I can put between the batteries and the 12v sockets etc that ensures only the right amount of voltage gets through?

 

[Steve Wright]

Usual caveat applies here about asking thick questions and all

When the leisure batteries are on charge, am I right in thinking that the voltage feeding the 12v sockets coming off the batteries will also be higher than 12v (i.e. will be the same as the charger is putting in)? Seeing as I have a Sterling B2B charger, that would mean the sockets may be fed up to 14.8v when the battery is being charged.

Could this damage any/all of the 12v appliances that are plugged in?

If so, is there some gadget I can put between the batteries and the 12v sockets etc that ensures only the right amount of voltage gets through?

When you say the batteries are on charge ! Do you mean when the engine is running ?

But to answer your question, no it won't do any harm using 12 Volt items while on charge as long as the battery is
connected, as it will act as a capacitor( the only time you cannot use any equipment if the max voltage stated is 12 volts)

 

[Lorin]

When you say the batteries are on charge ! Do you mean when the engine is running ?

But to answer your question, no it won't do any harm using 12 Volt items while on charge as long as the battery is connected, as it will act as a capacitor( the only time you cannot use any equipment if the max voltage stated is 12 volts)

Yes, when the engine running the Sterling charges the batteries. If the batteries are reasonable low it charges at anything up to 14.8v. The instruction manual for my Waeco fridge states that it must be disconnected from the battery if a high-speed charger is being used otherwise it will cause damage. Instead of having to do this all the time, could I simply install a capacitor between the battery and the 12v sockets and then leave the fridge etc connected?

 

[Jon Wildsmith]

A capacitor won't help you Lorin. Does your Waeco specify an upper voltage? I have a Waeco and a Stirling DC-DC charger and none of the magic smoke has escaped All devices designed to be used in a car should cope with a wide range of voltages so I wouldn't worry about it. A device that just happens to run off a 12v power brick but isn't designed for use in a car is different and might well object to the higher voltage.

 

[Graham]

Hi Lorin,

I would reiterate what has been said before.
While the battery is connected to the charger, then its very unlikley that no undue damaging high voltages are going to damage the fridge, as the battery acts as a big stabiliser/regulator.

If you tried to run your fridge directly from the charger without the battery, then you would not have the stabilising effect of the battery, and the charger would indeed provide a voltage, too high for the fridge to safely cope with.

Where previous was mention of a "capacitor" this is to be taken in the context that the battery is the capacitor, a storage device, not the traditional capacitor that we generally understand.

Graham

 

[Lorin]

Thank you all for the advice. That has set my mind at rest.