Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Is my math wrong?? My 200 watt panels are not even close to 200 watts..
#1
or.... are my batteries shot...??

Or... is my math wrong??

Or am I just not understanding the electric correctly...?

I finally got a digital meter for my battery bank... and now Im more.confused...


So here I am... Waking up to 14* temps, put the heat on, bout to make some coffee.

Battery voltage checks in at 12.6, while the charge controller is nicely blinking cause the sun is up...
I dropped down to 12.1 overnight, but it raised quickly once the sun was up.

So, I put the coffee on. Its Uniox water boiler. Supposed to be about 50-80 watts...

Turn it on, Battery immediately plummets to 12.0, then 11.9.....8... water is almost there and the battery has now stopped dropping and is holding at 11.4.... .

The charge controller does not give an over discharge warning...

Turning off the boiler, it immediately jumps back up to 12.1.. then quickly back to 12.6...

Finishing my water, meter holds steady at 11.4 volts..

Sooo... is it also possible my meter is just wrong??

Previous to having the meter, Id just use the electric and everything was hunky-dory... Now, numbers are worrying me...

Sent from my SM-N920T using Tapatalk
Started fulltiming 01/17 -  '98 Chevy Express 1500 Gladiator 
Add Thank You Reply
#2
I'd be suspect of the batteries first. Assuming these are Lead Acid type, I'd get shore power charger and hydrometer out. Charge the batteries and make sure water level is correct, then test with hydrometer to make sure they are fully charging and no bad cells. Once complete and all checks out, then reconnect them and turn on the boiler and see how the voltage reads.
80 even a hundred watts should not be pulling the voltage down more than a tenth or two.
Box Stock 2007 Ford E-150 All Build Pics HERE
Add Thank You Reply
#3
that boiler draws between 6.6 amps and 10 amps, not an light load but not real heavy either. what type of battery(s) and how old? highdesertranger
Add Thank You Reply
#4
Theyre sealed... no maintenance from what I understand... would I still need to check water levels?

Sent from my SM-N920T using Tapatalk
Started fulltiming 01/17 -  '98 Chevy Express 1500 Gladiator 
Add Thank You Reply
#5
One is a Walmart the other is Windy Nation. About a year old...? I have overdischarged them a bit, especially when I first started. Thing is, I have no idea if its 'normal' or Im just panicking because I can now actually see my vokts..

Sent from my SM-N920T using Tapatalk
Started fulltiming 01/17 -  '98 Chevy Express 1500 Gladiator 
Add Thank You Reply
#6
Less than a year.. actually, Feb 3rd marks my one year Vanniversary and I didnt get electric.til later... Lets go with six months old...?

Sent from my SM-N920T using Tapatalk
Started fulltiming 01/17 -  '98 Chevy Express 1500 Gladiator 
Add Thank You Reply
#7
will you be at the RTR? are they the same type battery? are they sealed lead acid(SLA), AGM, GEL? highdesertranger
Add Thank You Reply
#8
Keep in mind that in winter the shorter days and less intense sun produce a LOT less electricity in the panels than in summer......

Living in "Ziggy the Snail Shell" since May 2015
Add Thank You Reply
#9
I believe AGM. Im in the front now. Killed my starter battery. Waiting for Roadside assistance to give me a jump. The two arent connected. I just killed it last night by leaving stuff plugged into the cigarette lighter. ..

Sent from my SM-N920T using Tapatalk
Started fulltiming 01/17 -  '98 Chevy Express 1500 Gladiator 
Add Thank You Reply
#10
I see the same rapid voltage fluktuations on some of my old batteries. And on new small scooter and motorcycle batteries.
Scooter and motorcycle batteries can be a small as 4Ah to 12Ah.

This is one of the reasons that voltage meters is not the only (or optimal) way to determine how much energy is actually stored in a lead acid battery.

The voltage only shows how well, those parts of the surfaces of the battery plates that still works, are charged.

But if you are down to only 10% of the plate surfaces are still functional, then you are down to only being able to store 10-20Ah of energy is those "old" batteries.


It seems that some lead acid battery designs can only be "deep cycled"  2 to 10 times, before they are worn to the level where they have less than 10-20% of their original capacity left. Even if they show being charged to voltages way higher than 12.6V

I have no idea of how many deep cycles your particular batteries can withstand, but  it sounds like they have been "deep cycled" more than 10 times.

For some AGM batteries I have seen  claims of three times as  durable. But if that is just three times more of 2-10 times, then it is still only 30 deep cycles before they are toast.
So my thinking is, that low cost sealed batteries, may still not have very many times they can endure the deep cycle, even if they claim to be better than......

So the advice to never take a lead acid battery below something like 12V (or even 12.2V) is probably good advise for most lead acid battery designs. And in particular for sealed designs.
Add Thank You Reply


Possibly Related Threads...
Thread Author Replies Views Last Post
  A 1,500 Watt PSW inverter that can surge to 3,400 Watts Boyntonstu 25 980 11-01-2017, 04:49 PM
Last Post: This world isn't home
  $100 for 100 Watt SOlar Panels at Home Depot. 4-8-2016 One day only. ZOFCHAK 4 1,106 06-19-2017, 09:51 AM
Last Post: Vantastic
  320 Watt Cynergy Solar Panels, new in box for $109.00 Benjamin Dejo 13 3,487 08-27-2016, 03:25 AM
Last Post: NoLimit

Forum Jump:


Users browsing this thread: 1 Guest(s)

Powered By MyBB, © 2002-2018 MyBB Group.