New, charged battery shows 2/3 full

[pdalach]

I have a 2014 233s roo that I just purchased used.

Figuring the battery is toast, I bought two new 6v gc2 batteries and hooked then up in series. I also upgraded the converter to a boondocker 1255.

The battery reads full some of the time. But even when on shore power, the battery will read 2/3 a fair bit of the time...I noticed it recently when running the water pump.

Is this expected?

Thanks

[5picker]

What are you using to measure 2/3 charged? The indicator lights in the levels panel are notoriously incorrect.

[pdalach]

Just the indicator light.

I'm most concerned with not over draining the batteries.

[Mr. Dan]

It has been my understanding and experience that all 4 battery indicators lights will be on (regardless of battery condition/charge level) IF you are hooked to shore power AND your battery disconnect (if present) is set to the connect mode AND if your converter breaker is on and it's charging your battery.

[pdalach]

Originally Posted by Mr. Dan

It has been my understanding and experience that all 4 battery indicators lights will be on (regardless of battery condition/charge level) IF you are hooked to shore power AND your battery disconnect (if present) is set to the connect mode AND if your converter breaker is on and it's charging your battery.

Sounds like I can't trust the indicator light.

What are the alternatives? I'm not super excited about a long/expensive install to replace the indicator panel. Is the 1/3 indicator level somewhat accurate? And if so, isn't below 50% charge level considered "damaging battery" category?

[johnbryanpeters]

Originally Posted by pdalach

Sounds like I can't trust the indicator light.

What are the alternatives? I'm not super excited about a long/expensive install to replace the indicator panel. Is the 1/3 indicator level somewhat accurate? And if so, isn't below 50% charge level considered "damaging battery" category?

None of the indicators are accurate, and on mine, batteries are well below 50% charge when 50% light is still on. If you can't afford a battery monitor, get a wall mounted voltmeter - they're cheap.

[CHICKDOE]

mr dan stated it. first find out if the lights are in error on not. can you use a multimeter? unplug from shore power and take a battery voltage reading at the battery posts. then plug into shore power and take the same reading at the battery posts. this reading should be higher than the first reading, indicating that the batteries are getting a charge from the converter. if this is not true, ie the same reading. you need to determine why the batteries are not getting a charge (converter circuit breaker off, converter fuses blown, disconnect switch has batteries disconnected). resolving this will most likely get you all lights on the control panel. if you get a higher voltage reading when connected to shore power, then you probably have an issue with the lights on the control panel. but check the voltages first. you just bought it new, there may be an issue you do not know about.

[Kaadk]

The indicator lights are being misread. I’m guessing you lights are something like this or similar:



You’ll notice there’s a different scale for the batteries:

C - Charging
G - Good
F - Fair
L - Low

Anytime you’re not charging, the battery will be shown as ‘Good’, which is often confused as being 2/3rds because that’s the same light for 2/3rds on the tanks, but in reality it’s saying the battery is ‘full’(ish).

These lights just work on current voltage, so they’re terribly inaccurate if you’re actually trying to use them as a gauge of fullness of the battery. If you’re going to be dry camping and want to really check the state of your batteries, it’s best to invest in a true battery monitor.

[pdalach]

Didn't even notice the second battery specific markers.

That's embarrassing.

That leaves me wondering why it sits in the charge cycle as often as it does...something I can likely ask the supplier of the converter.

Thanks!

[Kaadk]

Originally Posted by pdalach

Didn't even notice the second battery specific markers.

That's embarrassing.

That leaves me wondering why it sits in the charge cycle as often as it does...something I can likely ask the supplier of the converter.

Thanks!

No worries, I used to make the same mistake when I first got my rig.

[Mr. Dan]

Originally Posted by Mr. Dan

It has been my understanding and experience that all 4 battery indicators lights will be on (regardless of battery condition/charge level) IF you are hooked to shore power AND your battery disconnect (if present) is set to the connect mode AND if your converter breaker is on and it's charging your battery.

This is true for every unit I've owned.

[5picker]

Originally Posted by pdalach

Didn't even notice the second battery specific markers.

That's embarrassing.

That leaves me wondering why it sits in the charge cycle as often as it does...something I can likely ask the supplier of the converter.

Thanks!

Any time you are hooked to shore power, all four lights should be on. While it is an indicator the converter is charging and supplying the necessary voltage, it isn't necessarily an indication anything is wrong. (ie: your statement, it sits in the charge cycle as often as it does)

But as we've all stated, the indicator lights are a terrible inaccurate way of knowing much about the 12v side of things.

[Cypressloser]

Originally Posted by pdalach

Sounds like I can't trust the indicator light.

What are the alternatives? I'm not super excited about a long/expensive install to replace the indicator panel. Is the 1/3 indicator level somewhat accurate? And if so, isn't below 50% charge level considered "damaging battery" category?

You could buy a 12 Volt 100 Amp DC Voltmeter/Ampmeter for around $10 on ebay to monitor battery voltage and current load, very easy to install and won't break the bank.
https://www.ebay.com/itm/Mini-Voltme....c100005.m1851

[clintbonnie73]

IMO... the only good way to accurately check the condition charge of your batteries is to use a Hydrometer.. Can be purchased at any auto part store.. price range is from $8 to $21.. Important, make sure your charge your batteries for a day or so first and then check with your Hydrometer, checking each cell and record the readings.. If all the cells are 100% charge, then you are good.. What brand of batteries are you using... just curious.. I don't like Interstate Batteries.. bad luck with them..

[garbonz]

If you don't care use the indicator light and don't worry, be happy. If you do care and want battery acid everywhere and if you can even get to the batteries and they are wet cells then a hygrometer works.

But if you really wan to know what is going on with some precision, buy a Victron or trimetric meter and install it. You then will know everything you need to know.

[Thurman]

Anyone who owns an RV, TT, 5-er should own a multi-meter and learn how to use one, they can be invaluable. Checking the battery voltage while connected to shore power and dis-connected to shore power is a good indicator as to the converter charging the battery. The battery voltage meter in post #13 is nice but, I have found that these type indicators can/will have a parasitic drain and can drain the battery down. There are models that have a push button to obtain a reading and IMO these are better. I went through three (3) deep cycle batteries within three (3) years and then I put a battery disconnect on my TT. Now I'm still on one I bought over two (2) years ago.

[Tom48]

Originally Posted by clintbonnie73

IMO... the only good way to accurately check the condition charge of your batteries is to use a Hydrometer.. Can be purchased at any auto part store.. price range is from $8 to $21.. Important, make sure your charge your batteries for a day or so first and then check with your Hydrometer, checking each cell and record the readings.. If all the cells are 100% charge, then you are good.. What brand of batteries are you using... just curious.. I don't like Interstate Batteries.. bad luck with them..

Doesn't hurt to use multimeter to verify battery voltage and at the same time check voltage at the back of the gauges to verify that they are the same. Shouldn't be any measurable voltage loss between the two.

[camaraderie]

The right thing to do if you're gonna boondock is get a Victron or Trimetric monitor and do the easy install to get a truly accurate picture at all times of battery state of charge and when it needs to be charged,, the exact time it is fully charged and the time remaining at current usage before you eed a charge. $150 and it WILL pay for itself

Second choice for about 50 bucks is a clamp on AC/DC meter which will let you see state of charge WHEN DISCONNECTED and a load has been applied. It will also tell you the amps being delivered by your boondocker and the voltage so you can see what stage of charging ou are in.

The least accurate means of measuring battery state of charge IN USE is the cheap $10 or fo voltmeter. It will accurately tell you if the battery is being charged. It will also tell you if the battery is dead. It will NOT telll you when the battery is full or half full accurately.

You don't need anything more than a voltmeter if you always plug in. If you boondock you need to take care of those GC's with a real monitor or you''ll end up with half the cycle life you'd otherwise get and spend twice what a monitor would have cost.
We all have our budgets...put this is one of those pay me now...or later deals if you boondock.

[pdalach]

With my very indoor wife, we won't be boondocking much. The one exception is this June we are heading to the Rockies...but I intend to use the batteries only for lights and enough juice to retract the sideout.

Good information on this forum...thank you everyone for the solid info.

[Skyliner]

Concur, get yourself a Trimetric of Victron Battery monitor. Can't live without my Trimetric.