Tuesday, November 30, 2010

Wiring Diagram

Above is the current wiring diagram I have in the van.  I recently had issues where battery C died, dragging down the system.  I used a battery checker - a little clear plastic device with a floater in it.  Battery C showed as weak while battery D showed as good (despite only measuring 7 volts when isolated from the system).  So battery C appears to have died and dragged down battery D's charge with it.  I took battery C home, replaced the fluid with fresh distilled water, and it charged up properly to 12V.  Hopefully that means the battery is now good.

Part of me wonders though, could my wiring be to blame.  Perhaps the right side is not charging like the left side and caused battery C to fail.

Thursday, November 18, 2010

More battery findings

So today had more sun and the meter was reading around 25V. I dug around and was able to pull the "quick disconnect" apart. They don't always want to disconnect, and certainly not quickly. The disconnect was the positive lead between the charge controller and the battery bank.

Immediately, the meter dropped to 22.58, which just verified that they had been getting power from the panel. I then left and came back 3 hours later. The voltage had dropped to ~20V. This confirms that at least one of the batteries is bad.

So next week, I'll bring down my battery tester (the one that measures specific gravity) and hopefully a nice funnel or water bulb (like you sue for ears) to refill the water in them.

If a battery is fully bad, they should have a multi-year warranty that I need to check out.

Tuesday, November 16, 2010

Gotta go, my battery is low.

So I've been noticing for a long time that my batteries seem to drain down at night. This was a minor annoyance previously, but now that there are only around 10 hours of sunlight in the day (sunrise ~7AM / sunset ~5PM), it has become a real issue as the batteries are now hovering around 20V and barely get above 22 after a full day's charge.

Now, the charge controller is supposed to have a night disconnect that prevents nighttime discharging through the solar panel. I had assumed that this was controlled by one of the potentiometers on the inside. So last week, I broke out the manual and went over all the details and found that they really only control how high it takes the voltage before it stops charging. They do not impact the low voltage disconnect. I did make a few adjustments to have it try to give more charge to the batteries. This seemed to have no affect.

So I emailed the Xantrex support people. They gave me a few troubleshooting tips, one of which is to determine if the batteries themselves are holding a charge. To test this, I would charge the batteries to full capacity (which at this point may involve taking them home), disconnecting the load and charge controller, and see if the voltage drops over a 12 hour period. If I had one, I could also try a DC clamp on ammeter to see if current is flowing to the solar panels.

I currently have no easy way to disconnect the solar panels. I have ordered two DC circuit breakers - 1 50A one for between the solar panels and the charge controller and one 100A for between the batteries and the load. Each breaker is around $25 so I will be adding $50 once I set these up.

Wednesday, November 3, 2010

Weather and Life


Last week, I took my van back home to get it's yearly inspection.  Unfortunately, the garage itself was out of stickers.  They could have scheduled me again for Monday, but I of course had to work Monday.  So we have one scheduled for Thursday, which means I'll be taking the van up a second time.


While I did have the van at home, I took the time to do some remodeling again. I cut the bed to be shorter (my length), made the desk a bit shorter (lengthwise, not height wise), and secured the sink to the side of the desk.  All in all, this gives me much more room to move about inside the van.

I also have brought down a microwave to heat soup up with.  I am not sure how well it works.  Transporting it the first time, it fell over, hit some junk I was transporting and dented.  I put my soup in on Monday to heat it up.  It ran, but made a whiny noise.  The soup came out tepid instead of hot, like I would hope.  I'll try it again next week (I only had the one can) for a longer period.


Things have been a bit chilly this week, with freezing/frost conditions in the morning.  I was supposed to bring my heater down with the van, but left it at home.  Despite this freezing weather, my sleeping bag still remains a viable source of protection from the elements.  Also, the temperature does warm up inside the van into the high 60s by mid-day.  On Monday, i even had to open a window and roof vent to let the cooler outdoor air in.