PWM Solar Controller Question

[LONG_KEELER]

I have the PWM solar controller set to 13.7v float charge.

Have checked that the controller only kicks as above.

Whenever I visit the boat , the battery voltmeter, and multi meter reading is always 14.2v.

Any ideas as to what I might be doing wrong ?

I have one 75 ah battery and 55 watts of solar .

TIA

 

[V1701]

I dunno but I think I'd ry setting the float to 13v & see what happens. I think those PWM controllers are not very sophisticated devices and that solar panel is capable of float charging significantly more than 75AH worth of batteries so I also wonder whether the charge gets higher than the voltage you've specified before the controller realises and cuts the charge...

 

[Norman_E]

55 watts should be quite enough to get the battery charged fully and the controller settled to float mode. Do you have anything connected that is draining current? e.g. gas alarm, bilge pump with a light on the panel telling you its connected, anything else? If so you might have enough current drain that your controller keeps in its bulk charge mode and does not drop to float mode.

 

[LONG_KEELER]

I dunno but I think I'd ry setting the float to 13v & see what happens. I think those PWM controllers are not very sophisticated devices and that solar panel is capable of float charging significantly more than 75AH worth of batteries so I also wonder whether the charge gets higher than the voltage you've specified before the controller realises and cuts the charge...

Good idea . Didn't think of that.

 

[lw395]

There are a lot of subtly different 'PWM' solar controllers out there.
I would presume this one is not switching to float.
Basically, you need to understand how it decides when to switch to float and ensure that's compatible with your battery and the way you use it.

Almost all solar controllers are designed around systems which get loaded every day, not boats which only get used at weekends.

But is 14.2V doing any harm? Is the battery fully charged and gassing? Can you add water regularly and all will be OK?

 

[LONG_KEELER]

55 watts should be quite enough to get the battery charged fully and the controller settled to float mode. Do you have anything connected that is draining current? e.g. gas alarm, bilge pump with a light on the panel telling you its connected, anything else? If so you might have enough current drain that your controller keeps in its bulk charge mode and does not drop to float mode.

I do have a watt meter permanently on that scrolls through peak amps, watts , cumulative AH, etc, so that is something for me to consider. Thanks.

 

[LONG_KEELER]

There are a lot of subtly different 'PWM' solar controllers out there.
I would presume this one is not switching to float.
Basically, you need to understand how it decides when to switch to float and ensure that's compatible with your battery and the way you use it.

Almost all solar controllers are designed around systems which get loaded every day, not boats which only get used at weekends.

But is 14.2V doing any harm? Is the battery fully charged and gassing? Can you add water regularly and all will be OK?

I was a bit concerned during lock down, but had a kind live aboard in the marina make regular checks.
There does not seem to be any gassing problems and nothing is warm or hot to touch.
The battery is sealed. Thanks

 

[Jmc1764]

My solar charge control has different settings for different types of battery, I think although could be wrong GEL type batteries need a higher charge voltage than WET Acid batteries, it may be worth checking if there is a similar setting on your unit ?

 

[Norman_E]

I do have a watt meter permanently on that scrolls through peak amps, watts , cumulative AH, etc, so that is something for me to consider. Thanks.

The meter won't draw much. Do you have a bilge pump?, If so is it running occasionally, as that would use enough current. I once had a small leak from a fresh water tank thar ran the bilge pump from time to time until I had the tank out and welded the leak.