Re: Can 24V circuit be available during batteries replacement?

The Mastervolt manual for the 24v/100A Chargemaster does not specifically state that the chargers must be used with batteries always.  However, this is strongliy implied, as it reads that batteries should be connected "under normal circumstances."  You are correct that Mastervolt customer service needs to be consulted and a clarification must be obtained.

Where the UK guy went wrong is that he said there is no need to setup the charger for this mode.  Via DIP switches, the charger can be set to constant voltage instead of 3/step.  In this case, voltage will be a constant 26.5V.  I do not recommend using the DIP switches on a Mastervolt charger.

The better solution is to use your PC and the MasterAdjust software (supplied free by Mastervolt) to set the chargers to constant voltage instead of 3/step, and to adjust the voltage to, for example, 25 volts, constant.  This way you do not have the charger switching from Float to Abs to Bulk as you turn on or add or drop loads from the system.

You can also use a Mastervolt EasyView display to do the same adjustments described above.  Much better than using DIP switches.


SM2K Nr. 350 (2002)
High and dry, Marmaris, Turkey

---In amelyachtowners@..., <svgarulfo@...> wrote :

Thanks Bill,

So I asked MasterVolt about using my ChargeMaster chargers as power supply only and I various answers:

In France, the guy said no. He said the chargers would suffer from being used that way and that the batteries act as a buffer for current picks and troughs. He does not recommend it. He said the charging cycle wouldn't be suitable for loads either. 

Next, in the UK, the guy said yes, but do not exceed 70% of the charger current capacity. No need to setup the charger in a specific mode (re: Alexander's reply with respect to his own system). Without batteries, the charging cycle will play in 17mins and stabilise the voltage after that. 

My conclusions are:
I'll follow Bill's recommendation as it is the safe way in the absence of a definitive answer.

I don't think MasterVolt's answers are completely contradictory. I would probably be happy to do it to run lights, pumps and a fridge fir a limited period of time, but not the bow thruster!

I wish MasterVolt had a clear power supply mode like Alexander's system. 


Fair winds

On Thu, 22 Jun 2017 at 14:40, 'Bill & Judy Rouse' yahoogroups@... [amelyachtowners] <amelyachtowners@...> wrote:

The answer depends on the batteries and your charger. 

And if I were you, I would leave one pair of batteries connected while you change the remainder, then change that one pair last. 

CW Bill Rouse
Admiral, Texas Navy
Commander Emeritus
Amel School
720 Winnie St
Galveston Island, TX 77550
+1(832) 380-4970


On Jun 22, 2017 03:37, "svgarulfo@... [amelyachtowners]" <amelyachtowners@...> wrote:

Hi all,

Can the 24V circuit be available if the chargers are on, when batteries have been removed -for example to be replaced and things get delayed...?





Amel 54 #122
Cap d'Agde, France

Amel 54 #122
Cap d'Agde, France

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