# Can using a battery charger harm a controller?



## budgetprepp-n (Apr 7, 2013)

I have a small (800 watts) gas generator that I can use to run a battery charger to keep my 
batteries up if we have an extended amount of days with no sunlight. (solar set up) 
I was doing some reading and something was said about ruining a controller by charging the
batteries with a battery charger. Anyone ever heard of this?


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## 8301 (Nov 29, 2014)

Since a solar controller simply controls the power from the panels to the battery a charger hooked directly to the battery bank shouldn't hurt it. Do not hook the generator between the panels and the controller; that could overload the controller. Instead hook the generator powered battery charger directly to the batteries. Realize that during times of solar production if the generator powered battery charger is running (changing the battery bank voltage as it charges them) the solar controller may think the batteries are fully charged and not allow the panels to charge the batteries.


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## SOCOM42 (Nov 9, 2012)

The quality of the charger may play a part also. If there is any ripple in the voltage, the inverter may not be able handle it. 
They are built to take in pure DC from the panels or batteries.
To be safe I would put a full wave bridge rectifier in between them.
The bridge should remove any residual ripple from the charger, you can add a couple of electrolytic caps too if needed. 
An O'scope would be nice to be able to see the output form.
If you had a scope you could see if just the caps would do.


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## 8301 (Nov 29, 2014)

SOCOM42 said:


> The quality of the charger may play a part also. If there is any ripple in the voltage, the inverter may not be able handle it.
> They are built to take in pure DC from the panels or batteries.
> To be safe I would put a full wave bridge rectifier in between them.
> The bridge should remove any residual ripple from the charger, you can add a couple of electrolytic caps too if needed.
> ...


The battery bank will stabilize any voltage ripples. I don't think he plans to hook the charger directly to the inverter.


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## SOCOM42 (Nov 9, 2012)

FoolAmI said:


> The battery bank will stabilize any voltage ripples. I don't think he plans to hook the charger directly to the inverter.


 if he goes on the battery side he will be ok.
I thought I read it to be on the panel side.


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## 8301 (Nov 29, 2014)

budgetprepp-n said:


> I have a small (800 amp) gas generator that I can use to run a battery charger to keep my
> batteries up if we have an extended amount of days with no sunlight. (solar set up)
> I was doing some reading and something was said about ruining a controller by charging the
> batteries with a battery charger. Anyone ever heard of this?


Just a quick thought, If your gas generator is 800 amps it isn't small. I'd suspect that instead your generator is 800 watts.


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## budgetprepp-n (Apr 7, 2013)

FoolAmI said:


> Just a quick thought, If your gas generator is 800 amps it isn't small. I'd suspect that instead your generator is 800 watts.


Opps yes 800 watts


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