Solar/ leisure battery performance.

Phantom

Phantom

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My 2005 MH is pretty sorted to my liking now though feel that the leisure battery performance could be questionable but is probably not? Just using an LED TV for 4 or 5 hours can have the solar charger indicating that the leisure batteries are low. The solar controller is the type that the LED for battery charge state is either green, yellow or red, and flashing green for fully charged. Alternatively I can take a battery voltage reading via a cigarette lighter socket, usually shows 13.0 or 13.1 when charging well or fully charged, but is still not an ideal way to know your battery status so maybe I could do with some device that would accurately monitor and indicate the actual percentage of remaining battery power? Any recommendations welcome.

My current set up is a 120w solar panel with two leisure batteries rated 110 & 115 amps connected in parallel so potentially 225 amps in an ideal world. Just a few hours of morning sun or a drive will normally soon replenish the batteries from the previous night's use, so doesn't seem like they were actually that low? I added the second leisure battery just last year after the panel tripped out due to low voltage but when going to fit the new battery found a loose battery terminal on the original, I can't vouch for the original's health though but feel it is okay, and as it was already wired to take a second battery I just connected it up. I guess that I just really need a better battery status indicator that can measure power our and in? So what is good?
 
I think a Voltmeter at the very least would be a massive step forward from indicator lights.
And a Battery Monitor that incorporates an SOC reading would be a big jump up from that.
Two very popular options are the Victron BMV range and the NASA Marine models. Each have their own pluses and minuses and fanbase :)
I have a bit of a write-up of this subject on my website - https://www.wildebus.com/power-management/
You can get other generic SOC Monitors for a fair bit less - you would need to look at spending from around £40 or so and upwards.
 
Your biggest problem is trying to replace the 15A of power that your tv is using. In late summer in the Uk you will be lucky to get 3A for a couple of hours at midday. Driving will put more back in.
 
Phantom said:
My 2005 MH is pretty sorted to my liking now though feel that the leisure battery performance could be questionable but is probably not? Just using an LED TV for 4 or 5 hours can have the solar charger indicating that the leisure batteries are low. The solar controller is the type that the LED for battery charge state is either green, yellow or red, and flashing green for fully charged. Alternatively I can take a battery voltage reading via a cigarette lighter socket, usually shows 13.0 or 13.1 when charging well or fully charged, but is still not an ideal way to know your battery status so maybe I could do with some device that would accurately monitor and indicate the actual percentage of remaining battery power? Any recommendations welcome.

My current set up is a 120w solar panel with two leisure batteries rated 110 & 115 amps connected in parallel so potentially 225 amps in an ideal world. Just a few hours of morning sun or a drive will normally soon replenish the batteries from the previous night's use, so doesn't seem like they were actually that low? I added the second leisure battery just last year after the panel tripped out due to low voltage but when going to fit the new battery found a loose battery terminal on the original, I can't vouch for the original's health though but feel it is okay, and as it was already wired to take a second battery I just connected it up. I guess that I just really need a better battery status indicator that can measure power our and in? So what is good?
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I believe when you change a battery you should not add one , you should replace both batteries and at the same time.
 
Okta said:
That sounds very low for a charging voltage, I think you need more than that to get a full charge and avoid sulphation.
ps count me in the Victron BMV fanbase.
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I have this controller which will likely be the 10 Amp model for my 120w solar panel.
https://docs-emea.rs-online.com/webdocs/146f/0900766b8146fdd7.pdf
"The controller will focus its power delivery on the battery connected to the No 1 terminals until that battery is 70% fully charged. Once this is reached power will be delivered to both batteries equally until both are 100% charged."
The lights are currently flashing green to indicate both fully charged batteries. But with a multimeter the leisure batteries are 13.14v and the new starter battery is 12.8v. I don't think I have ever seen a voltage above 13.3v except when being charged from the vehicles alternator. Does that seem right?
 
Phantom said:
I have this controller which will likely be the 10 Amp model for my 120w solar panel.
https://docs-emea.rs-online.com/webdocs/146f/0900766b8146fdd7.pdf
"The controller will focus its power delivery on the battery connected to the No 1 terminals until that battery is 70% fully charged. Once this is reached power will be delivered to both batteries equally until both are 100% charged."
The lights are currently flashing green to indicate both fully charged batteries. But with a multimeter the leisure batteries are 13.14v and the new starter battery is 12.8v. I don't think I have ever seen a voltage above 13.3v except when being charged from the vehicles alternator. Does that seem right?
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The document for the controller says it should give an equalisation voltage of 14.6v. Are you seeing this voltage? Perhaps the panel and controller are struggling to to provide enough power for 2 leisure and 1 engine battery, especially now the sun is lower and daylight shorter.
 
Measured at the controller the solar voltage going in is in the range of 13.3v to 14.4v. Shouldn't it be higher, like about 16v?
 
If you have a lead acid battery, I don't think it would like 16v.


Ignore this. I was thinking of battery voltage.
 
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Voltage going in at full sun over head should be much higher,you should be seeing 14.4 on meter at battery,do you have a pwm or a mppt regulator,wildbus is the man for this stuff,listen to what he says as he is doing a lot of testing on this.
 
Phantom said:
Measured at the controller the solar voltage going in is in the range of 13.3v to 14.4v. Shouldn't it be higher, like about 16v?
Click to expand...

If you have a PWM Controller - which you indicate you have, then I would say the voltage into the controller will be as you have measured. If you have the controller set to charge at 14.4V (quite typical), then once the battery gets to absorption level, you should be reading around 14.6V at the soalr input on a PWM.
If you have an MPPT, then it would be as you think it should be - >16V just about all the time when there is daylight

It's the way PWM controllers work - they cut the voltage down to a few 10ths of a volt above the Battery voltage.
If you want an idea of what you could get in if you had an MPPT, remove the battery +ve or -ve and then measure the controller voltage :)
 
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