Charging time

Craigmarc

I was wondering how long my batteries should take to charge they have been charging for two weeks now and haven't gotten beyond 0-35 percent charged. I am only using them to charge my cell phone and run a propane refrigerator which use dc to ignore the propane.

I have two 265 watt solar panels and four batteries with a total of 610 a/h. The batteries are charging with a absorption voltage of 14.3.

mike74820

ive been checking my system to see when it hit float,  and today it went to float at 2pm.  ive got 300 watts going to 235 hr battery bank

vtmaps

What batteries? 

Also, how much current does that propane fridge use?  If you are not using propane, then the fridge will be extremely inefficient when operating on electric power (AC or DC). 

--vtMaps

Craigmarc

The refrigerator is running on propane it just uses 12dc the light the flame and run a led console so I imagine it draws very little current. I'm thinly that something must be wrong with my batteries or some other component of my solar system since it was installed two weeks ago has had very little current drawn offf of it and it still won't charge my batteries.

Photowhit

Okay, treat us like we know nothing about your system, what batteries, charge controller and system voltage? Do you have an inverter attached. Do you have a volt meter integrated into the system or can you take voltage readings?

Any other know loads on your system?

petertearai

Hi . at  a glance . if you have floaded batterys, the absorb voltage looks a little low . Also with that amount of battery i think you need more pv  to get the required amps in .

vtmaps

petertearai said:

Hi . at  a glance . if you have flooded batterys, the absorb voltage looks a little low . Also with that amount of battery i think you need more pv  to get the required amps in .

Those were my first thoughts, but I figured I had better wait for clarification on the batteries... are they AGM?  are they really 610 ah at 12 volts?  does OP really have virtually no loads?

--vtMaps

Craigmarc

The batteries are sun xtender pvx-3050t 4 6 volts batteries wired two in parallel and two in series for a twelve volts system. They are 305 a/h, bulk charge 7.1-7.2, float charge 6.6-6.7. I am charging with an tristar mppt 45. I don't have any way to check the voltage but the yellow and red lights are lit on the mppt indicating a 0-35 percent charged and after two weeks haven't gone any higher.

Craigmarc

Also I have an inverter but it is shut off for now because I don't want to drain the batteries any further.

vtmaps

At least part of the problem is that you do not have enough solar panels to charge the batteries properly.   Under typical mid day conditions you only have about 408 watts available to charge the batteries (assuming NO loads).  At a charging voltage of 14.4 volts, that is a charging current of about 28 amps.  That is a bit low for a 610 ah bank, but I am not sure that is your entire problem.

Craigmarc said:

I don't have any way to check the voltage but the yellow and red lights are lit on the mppt indicating a 0-35 percent charged and after two weeks haven't gone any higher.

You do need to get hold of a DVM (digital volt meter) if you are going to troubleshoot the system.

--vtMaps

Photowhit

Craigmarc said:

The batteries are sun xtender pvx-3050t 4 6 volts batteries wired two in parallel and two in series for a twelve volts system. They are 305 a/h, bulk charge 7.1-7.2, float charge 6.6-6.7. I am charging with an tristar mppt 45. I don't have any way to check the voltage but the yellow and red lights are lit on the mppt indicating a 0-35 percent charged and after two weeks haven't gone any higher.

Okay, did you really set the charge controller to 7.1 - 7.2 volts and float at 6.6 - 6.7 volts?

Can you disconnect the strings and see if one gives you a different reading? In string might be dead and the other losing voltage trying to maintain it. After being disconnected and sitting for 20-30 minutes, one might give you a middle range. Worth checking until you get a meter.

Craigmarc

No the charge controller is set to 14.3. 7.1-7.2 are the batteries specs.

westbranch

Can you post a picture or 3 of the setup, showing connections etc from the panels to the CC to the battery?

Mountain Don

Have you tried charging the batteries while all the loads are turned OFF?  Will the batteries actually come up to full charge with no loads?

I agree that it would seem you need more PV capacity for that much battery capacity.  As has been mentioned a complete list of the components you have along with configuration / setup info and general location is needed to be of most help.

Craigmarc

Here are some pictures im not sure how much they will help. I haven't turned off all the loads because i need to keep my refrigerator running and charge my cell phone occasionally. The refrigerator is a norcold propane refrigerator I haven't been able to find out how much current it draws but I don't think that it is too much during propane mode. Also my location if Flagstaff as and I've been getting plenty of sun lately but the batteries still haven't gotten beyond 0-35 percent charged.

BB.

How do you know state of charge?

If flooded cell, need a hydrometer for accurate measurements.

Otherwise, use a good digital volt meter and tell us the charging voltage, and how many hours the charger holds the voltage.

Also, what is the voltage of the battery bank (and each battery) later on the evening?

-Bill

Craigmarc

The yellow and red lights are on on the charge controller indicating that the batteries are 0-35 percent charged.

BB.

I would highly suggest a Sears AC/DC current clamp DMM and a Hydrometer (this one is very nice/easy to use).

The controller may be correct, or it may not be. You need some sort of verification. They hydrometer is the "gold standard" for flooded cell batteries state of charge estimates.

The Sears meter is about the cheapest DC Current Clamp DMM I have seen that works "good enough" for your needs. The voltage measures to debug your system. And the DC current clamp so you can confirm current flow is what you expect.

-Bill

westbranch

Am I seeing tings or is there a curve in the vertical surface, where the Sunextender data sticker is?
this could be an indicator of internal problems with that (AGM?) cell where the red,positive, cable is connected...

Craigmarc

You mean the wall of the battery? Yeah they all have kind of a convex shape I was wondering if there might be something wrong with the batteries. They were at less then 35 percent charged when they were hooked up is that normal?

BB.

It can be normal to have the case look a bit inflated--There is usually an over-pressure valve in the cap that will vent at ~1-2 PSI.

Can you measure the voltage across each battery when charging? Running a bit of pressure in an AGM/VRLA battery would seem to indicate that the battery is getting at least the minimum charging voltage (should be hitting and holding ~14.2-14.4 volts for a few hours if all is OK).

AGM/VRLA batteries should actually be spaced apart (an inch or more) so that they have good cooling. The inner batteries could run hotter if they do not have good air flow around the cases.

-Bill