Charge controller settings for unknown calcium/lead acid battery

paddo

New Member
Hey Everyone... Just a bit of a brief backgound on the project I'm currently putting together for my Mother .. Essentially the panel and battery only has to run a small pump to keep the water moving in the pond a little bit.. Doesn't really matter how long its on/off for, I was thinking fully charge the battery and then run the pump until the battery is low and then stop the pump and charge back up kinda affair.
She wanted a small fish pond and asked me to make a water feature for it, So the setup I got for her was the following.. A 50w solar panel, 12v 90ah sealed calcium/lead acid leisure battery with no info on it whatsoever.. That was the only info I got from the Ebay seller ! And a cheap ebay 15 quid 12v 30A PWM charge controller... The load is a small 7w submersible water pump to run the water fountain in her pond...
Now the issue really is... What general recommended charge/discharge settings would you say would be ideal for this type of battery chemistry ?.. I've nothing much to go on as It was an ebay battery purchase.. Quite a lot of them sold and it cost about 80 quid or therabout's.. Actually I ordered a 50ah one and they were out of stock of them so sent me a 90ah instead.. As far as I see on the controller theres provisions for float/discharge stop/discharge reconnect
So with that being said.. What would you guys recommend for those settings ? Like at what voltage is this battery considered fully charged.. and should there be a certain percentage I can safely discharge it down to without to much stress..
As you can probably guess, I'm not up to speed on charging with a solar charge controller...

Cheers

Pat
 

snoobler

Solar Honey Badger
Welcome to the forum:

Battery capacity: 12V * 90Ah = 1080Wh

1080Wh/7W= 154 hours run time.

7W * 24h = 168Wh used per day by pump

50W panel should be able to pull in 200-250Wh/day with good sun.

14.4V absorption
13.2V float
12.2V cut-off to prevent over-discharging the battery.

A cheap 10A PWM charge controller with configurable load ports would work.

With good sun, it should run 24/7.
 

mikefitz

Solar Addict
Have you a link to the PWM controller?
Some have user control for settings of the load outputs, if so, you could turn off the load outputs when the battery voltage fall to low and on again when it reaches a higher voltage. It seems you have this with the discharge control, stop at 12.4 volts, reconnect at 13.2 volts, would be settings to evaluate. Ideally you dont want to discharge the battery too much yet have a reasonable run time for the pump. Since its a feature, the pump does not need to run over night? Keep the 'stop' voltage as high as possible so the battery state of charge is in the high region.
Charge settings of 14.4 volts absorption ( maybe termed 'boost') and a float of 13.8 should be suitable for the battery.
SOC.jpg
Mike

sorry Mod , was typing as you posted
 
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paddo

New Member
Hi guys, sorry different time zone here I guess.. I'm located in Ireland..
Unpon further investigation into the charge controller, it seems that the absorbsion voltage is preset depending on the 3 options to select in the menu.. Theres b01..Lithium 12.6v B02 Gel 14.2v and B03 Flood 14.6v So im assuming my only option is to select flood.. Although it seems it has a higher bulk absorption rate than you guys suggested 14.6v as opposed to 14.4v.... Don't seem to be able to change that..
There's is also a load output menu but as its broken chinese english in the manual I interpret it as 24hr selectable cuttoff of the load output..
theres 3 settings or well 3 interpretations of what it is..
[24h] load output 24 hours
[1-23h] load on after sunset and closed after setting hours
[OH] dusk to dawn

Am I right in guessing that I would just leave it on 24h as in its on when its charged up and turns off when the battery is depleted down to the discharge stop setting? Im going to also assume that there will be a substantial amount of time that the pump is off, as im completely recharging the battery before the load comes on again.. Which leads me onto the part im most puzzled about, the discharge reconnect and float.. why couldn't I just set the reconnect to 14.6 v as in a fully charged battery ? Is it because the voltage actually drops back down, the bulk charge actually briefly increases the voltage above the nominal !!! And what exactly is float then ? Sorry between chinese english and getting a grasp on solar charging, im slowly coming round to it... Im well versed in Lithium as I use it quite often in my model planes..

cheers

Pat
 

mikefitz

Solar Addict
I am in the UK so same time zone. The load outputs of low cost PWM controllers are primarily designed to control lighting, typically you may want the lighting to be active from dusk till midnight. To prevent the battery from discharging too much the 'stop' and 'reconnect' are used.

The 'float' voltage is a value that a charger should default to once the battery is chargesd, this will keep the battery 'topped up' without degrading the battery too much. Many of the low cost controllers may not enter this mode.

With the settings you have flooded at 14.6 charge should be OK. If there is an option for float volts 13.4 to 13.8 volts will be suitable. Since your battery is a standard vehicle calcium battery designed to be charge at a constant 14.4 volts, the actual voltage wont matter.

Th amount you discharge the battery will determine the battery life, it was never intended to be cycled. As a starter battery the degree of discharge in the intended application would be a small fraction of capacity. If you cycle to a low state of charge its usable life will be short. You have a high ratio of panel power to pump requirements, so with reasonable solar conditions the battery will fully charged during daylight. Setting the stop/reconnect volts will determine performance time of the pump under poor solar or darkness.

As I suggested you will have to play around with the stop and reconnect voltage settings to get a useful operating time for the pump without discharging the battery too much. Setting the reconnect to 14.6 volts may be one option but exactly how the pump, battery and solar play together wont be known until the systen is functioning.

Typical charge time graph of lead acid batteries,
charge graph.jpg
Mike
 

paddo

New Member
Cheers for the help mate... Used to Live in London myself up until last summer, Spent a good few years working up and down England ;)
About the battery... Well at least I hope its not just a standard car battery otherwise I got conned, Here's a link to the exact one I have, Says Dual use Leisure and starter anyways..

Anyways like I was saying, Im not too concerned about the times the pump is on or off at... It just trickles water for a nice sound effect kinda vibe when its on and helps stop the pond from freezing in the winter I hope..

Cheers
 

paddo

New Member
BTW.. Heres a few pics of the setup... Don't mind th2.jpge state of the pond.. Its being emptied to clean out for incoming fish :giggle:
 

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mikefitz

Solar Addict
Says Dual use Leisure and starter anyways.
Its a low cost starter battery, its either an EFB, enhanced flooded battery, or an AGM, absorbent glass mat, one or the other, it cannnot be both. The company you bought from is a small car accessory shop. The battery is most likely a Turkish made battery using the name of the Polish Company. A search of the net throws up muliple issues with Number One Batteries and the owner.
No doubt it will power your pump for a time but dont expect a long service life.
no 1 car parts.jpg
Mike
 

Phil.g00

New Member
Silver Calcium batteries need about 0.8 to 1V higher than standard lead acids. So take standard lead-acid settings and adjust the various voltage thresholds upwards accordingly.
 

paddo

New Member
Lol... No I was under no illusions that it would be a very good battery.. Ive seen the prices of them for a decent one.. But Its enough for a very small load I was thinking... Was just hoping that it wasn't just a generic car battery because I could have just bought one of those in the local garage for buttons.. 😣 I suppose that means that I cant discharge it too low considering its mostly designed for short draws of current.. Maybe 70-80% then so 12.3 12.4 cuttoff ??
 

paddo

New Member
The battery is most likely a Turkish made battery using the name of the Polish Company. A search of the net throws up muliple issues with Number One Batteries and the owner
Jesus !! I just looked at some of the reviews there !!! Wow what a bunch of $%%%holes... Selling low quality knockoff stuff for years and just switching up the name and closing and opening company's.... Im pretty annoyed at myself f and for buying one now to be honest.. I couldn't check up the battery when I was buying it so assumed foolishly that it was probably an OEM just rebranded.. Luckily I just have the one and its use is minimal.. Id be severely bummed if I bought a stack of them for a mobile home or something. I'm sure lots have..
 

paddo

New Member
Hi guys just an update on the status of my project... I think Im going to bin the pwm charge controller.. I think its just overcharging the battery and not actually cycling to a float voltage at all... It just seems to want to stay topped up to the max which Ive a feeling is even over the 14.6v absorbtion it states.
Any suggestions on a reliable low cost controller for this project ? I know you get what you pay for.. But just because this isnt a consumer setup and just a small pump in a fish pond.. Id like to keep it as cheap for my Mum as possible..

Cheers

Paddy
 

mikefitz

Solar Addict
Anybody Know anything about these
Not that specific unit but many of the low cost PWM use similar 'insides'. I have evaluated several and most fail to operate as specified, the usual problem, as you have found is over charge.
Since its Amazon that offer that controller and similar at low cost units you could evaluate one, returns are easy.

The lowest cost MPPT controller available is the tracer 1206.


Mike
 

paddo

New Member
Thanks for the advice mike... If it were me personally id go with a mppt and forget the hastle, But trying to convice my old Mum is another story.. Needless to say she wasnt happy with me already when I had to tell her that the battery was crap and now the charge controller is potentially crap.. I was the one who convinced her to get a little solar setup in the first place..GULP !!!
In other news ive been keeping an eye on the current charge controller again.. Weather has been great the past 2 weeks so the panel was probably fairly effecient at keeping the battery topped up.. Now My understanding is,I might have gotten the screens mixed up.. the voltage has actually dropped to 12.6v down from 13.8v.. today is cloudy just for reference.. So Maybe the controller is trying to keep at the float voltage setting actually when the sun is out.. For the last few days its been what seems like trying to keep the voltage at 13.8v which is the float I set... Maybe it will never do a bulk phase at all, but try and keep at the float ?? Anyways today like I mentioned its down to 12.6 volts.
For the last few days with full sun, I could see what looked to me like the controller constantly switching on and off the panel and then reach 13.8volts
It would drop to 13.4 or around that and then back up to 13.8....
If that's what its actually doing instead of bulk charging, would that be fine ?
My only major concern is that the cuttoff voltage I've set is by default quite low even at the max setting.. the max I could set it to was cuttoff at 11.5v.. No way to adjust it above that, only lower down to 10.7 v which might be if you were using Lithium cells..

Cheers

Paddy
 
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