I am in the process of installing the battery charging system in a sailing boat which will have an electric propulsion motor. It’s a 24v system with six, 100ah batteries in two banks of three. I will have a 24v solar panel array charging the batteries through a 45amp 24v charge controller. My question is: Is there any reason why I cannot use this same controller coupled to a 24v power supply to load the batteries either from shore supply or an auxiliary generator using a manual switch to chose between the supply method? From what I can gather a solar charge controller seems to have all the properties of a high end battery charger but of course needs a compatible dc power supply. Am I correct in my assumptions or are there reasons why it will not work?
I would appreciate any input. Peter
Hybrid system
Moderator: Peak Moderation
Boat query
Hi,
Interesting project, just 2 thoughts :
"recharging from shore" That means from the mains? If yes, then you would need a different appliance ie battery charger for mains use (AC)
What is the power of your array? Solar panels to charge such a big set of batteries will need to be quite big... Is a little wind turbine possible on your boat?
This charger is for both solar / or wind, as long as an generator gives you a current which is in the range of ccurrent and voltage of your controller I think that should be fine
Interesting project, just 2 thoughts :
"recharging from shore" That means from the mains? If yes, then you would need a different appliance ie battery charger for mains use (AC)
What is the power of your array? Solar panels to charge such a big set of batteries will need to be quite big... Is a little wind turbine possible on your boat?
This charger is for both solar / or wind, as long as an generator gives you a current which is in the range of ccurrent and voltage of your controller I think that should be fine
Hi sjaglin, Thank you for your post. I also wrote to a few companies that make controllers and this was the answer I received:
(I think the source of the DC is largely irrelevant and the controller should be fine as long as the current doesn't exceed the specified ampage. Therefore it ;possible to obtains all the benefits of PWM from your shore source.)
My purpose of doing it this way is to charge the bank up to float level with the shore power/generator and then switch to the solar array to top up.
As most of my sailing is on a lake with access to shore power, I have no plans at present to incorporate wind power which is always an irritation to neighbors in a marina.
I was convinced that this system would work but not being an electrician I have previously found to my cost that logic isn't always true.
Peter
(I think the source of the DC is largely irrelevant and the controller should be fine as long as the current doesn't exceed the specified ampage. Therefore it ;possible to obtains all the benefits of PWM from your shore source.)
My purpose of doing it this way is to charge the bank up to float level with the shore power/generator and then switch to the solar array to top up.
As most of my sailing is on a lake with access to shore power, I have no plans at present to incorporate wind power which is always an irritation to neighbors in a marina.
I was convinced that this system would work but not being an electrician I have previously found to my cost that logic isn't always true.
Peter
May be of interest:-
http://www.powermastersystems.com/Template_000.htm
I have one at home and use the mains as 'shore power' to top up the batteries when my PV system isn't generating enough to keep it topped up. Highly recommended.
http://www.powermastersystems.com/Template_000.htm
I have one at home and use the mains as 'shore power' to top up the batteries when my PV system isn't generating enough to keep it topped up. Highly recommended.
Andy Hunt
http://greencottage.burysolarclub.net
http://greencottage.burysolarclub.net
Eternal Sunshine wrote: I wouldn't want to worry you with the truth.
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adam2
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Re: Hybrid system
I dont think that it will work.classboat wrote:I am in the process of installing the battery charging system in a sailing boat which will have an electric propulsion motor. It’s a 24v system with six, 100ah batteries in two banks of three. I will have a 24v solar panel array charging the batteries through a 45amp 24v charge controller. My question is: Is there any reason why I cannot use this same controller coupled to a 24v power supply to load the batteries either from shore supply or an auxiliary generator using a manual switch to chose between the supply method? From what I can gather a solar charge controller seems to have all the properties of a high end battery charger but of course needs a compatible dc power supply. Am I correct in my assumptions or are there reasons why it will not work?
I would appreciate any input. Peter
Most PV charge contollers short circuit the PV input when the battery is full, this is fine for for PV modules but would would be liable to damage a mains operated DC power supply.
To charge your 24 volt battery from the grid, or from a generator, purchase a 24 volt battery charger.
A very basic one could be as cheap as £20, though a better qauility more expensive model would be better.
"Installers and owners of emergency diesels must assume that they will have to run for a week or more"
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adam2
- Site Admin
- Posts: 11014
- Joined: 02 Jul 2007, 17:49
- Location: North Somerset, twinned with Atlantis
A blocking diode wont help.
Blocking diodes are installed to prevent a battery discharging into a PV module at night, or for similar purposes.
They wont prevent a PV charge controller from short circuiting the power source when the battery is full or nearly so.
The short circuit current of a PV module is only very slightly higher than the normal load current, and no harm comes from short circuiting them.
A D.C. power supply though will "try" to supply a very large current if short circuited, and would probably be damaged, and might well damage the PV charge controller.
Another problem would be selecting the correct voltage. If the power supply has a voltage even slightly lower than the battery voltage, then no charging would result. If the voltage was higher, then an excessive current would flow and be liable to damage the charge controller, the battery, or the power supply.
I would simply buy a battery charger.
For unattended use, a good qaulity fully regulated version should be used.
If however you dont mind monitoring the charging, and turning off when done, then a much cruder charger will serve.
Blocking diodes are installed to prevent a battery discharging into a PV module at night, or for similar purposes.
They wont prevent a PV charge controller from short circuiting the power source when the battery is full or nearly so.
The short circuit current of a PV module is only very slightly higher than the normal load current, and no harm comes from short circuiting them.
A D.C. power supply though will "try" to supply a very large current if short circuited, and would probably be damaged, and might well damage the PV charge controller.
Another problem would be selecting the correct voltage. If the power supply has a voltage even slightly lower than the battery voltage, then no charging would result. If the voltage was higher, then an excessive current would flow and be liable to damage the charge controller, the battery, or the power supply.
I would simply buy a battery charger.
For unattended use, a good qaulity fully regulated version should be used.
If however you dont mind monitoring the charging, and turning off when done, then a much cruder charger will serve.
"Installers and owners of emergency diesels must assume that they will have to run for a week or more"