Battery indicator readings

[mbike254life]

I currently own a 2022 Cherokee 264DBH. I am a little confused as to which indicator I should use to read my batteries current charge level. Attached are 3 pics of the various indicators 1. Is the solar charge controller located in the front storage bay 2. The dc voltage indicator near my panel 3. The battery button which lights up 4 small lights on the panel

Anyone know which one is giving my the right reading? Just upgraded to a lithium battery and I am still learning about how everything runs and operates off the battery. I understand that the voltage reading indicates how much “power” is left and I have I know that 13.1 for example is about 40% battery left (according to solar charge controller). But why are the other reading so different? 13.0 V and essentially what appears to be 4 lights indicating full charge. Thanks for any insight.

[BehindBars]

Originally Posted by mbike254life

Attachment 285161Attachment 285162Attachment 285163

I currently own a 2022 Cherokee 264DBH. I am a little confused as to which indicator I should use to read my batteries current charge level. Attached are 3 pics of the various indicators 1. Is the solar charge controller located in the front storage bay 2. The dc voltage indicator near my panel 3. The battery button which lights up 4 small lights on the panel

Anyone know which one is giving my the right reading? Just upgraded to a lithium battery and I am still learning about how everything runs and operates off the battery. I understand that the voltage reading indicates how much “power” is left and I have I know that 13.1 for example is about 40% battery left (according to solar charge controller). But why are the other reading so different? 13.0 V and essentially what appears to be 4 lights indicating full charge. Thanks for any insight.

Use a known good, calibrated digital voltmeter on the battery itself, then choose the indicator that most closely matches that reading. Why are they different? They’re cheap. It also depends on the measurement point, be it at the battery, or at a load downstream. Voltage drops in the wiring due to current flow can affect the measurement.

[mbike254life]

Originally Posted by BehindBars

Use a known good, calibrated digital voltmeter on the battery itself, then chose the indicator that most closely matches that reading. Why are they different? They’re cheap. It also depends on the measurement point, be it at the battery, or at a load downstream. Voltage drops in the wiring due to current flow can affect the measurement.

Thanks for the reply, very helpful. I think the solar charge controller is closer to the battery and probably has the best reading. But I just ordered a voltage meter. Thanks again.

[BehindBars]

Originally Posted by mbike254life

Thanks for the reply, very helpful. I think the solar charge controller is closer to the battery and probably has the best reading. But I just ordered a voltage meter. Thanks again.

I would also put my bets on the charge controller being best. For testing, even the $5 DVMs from Harbor Freight are fairly accurate.

[tomkatb]

The answer is they are all correct. You need training in how to read them!

The four led thing is worthless. 4 means a charger is on.

Three mean it’s pretty good sort of. Two, means neatly dead. One is doa.

A wet cell battery is 0 to 12.6 volts. Any reading over 12.6 is, something is charging me! About 12.0 is 50%. The lowest you should allow them to get.

Then too. When you charge a battery the residual after an hour or more gives a meaningless higher reading. Thus you have to be trained.

Lithium is a different deal.

I converted our rv to lithium about 3 weeks ago.

It is best to read all your meters after dark several hours without plugging into shore power. Full charged our batteries are about 13.5.

First meter, the led. Means the batteries are being charged.

Second is the voltage coming from the solar panel. Third is a voltmeter likely being read with a residual charge.

All correct!

[bikendan]

Unplug from shore power and then see what the readings are.

Sent from my SM-G781U using Forest River Forums mobile app

[mbike254life]

Originally Posted by bikendan

Unplug from shore power and then see what the readings are.

Sent from my SM-G781U using Forest River Forums mobile app

I am unplugged from shore power.

[mbike254life]

Originally Posted by tomkatb

The answer is they are all correct. You need training in how to read them!

The four led thing is worthless. 4 means a charger is on.

Three mean it’s pretty good sort of. Two, means neatly dead. One is doa.

A wet cell battery is 0 to 12.6 volts. Any reading over 12.6 is, something is charging me! About 12.0 is 50%. The lowest you should allow them to get.

Then too. When you charge a battery the residual after an hour or more gives a meaningless higher reading. Thus you have to be trained.

Lithium is a different deal.

I converted our rv to lithium about 3 weeks ago.

It is best to read all your meters after dark several hours without plugging into shore power. Full charged our batteries are about 13.5.

First meter, the led. Means the batteries are being charged.

Second is the voltage coming from the solar panel. Third is a voltmeter likely being read with a residual charge.

All correct!

Thanks for the reply. I attached some pics of the other indicators as well, since I knew that the 4 led indicator is pretty much useless.

I got the separate voltmeter as someone suggested and interestingly the closest reading was not the solar charger, but the meter near the panel (not the 4 led’s). So for context…

The voltmeter read 13.1 at the batter
The solar charger is reading 13.4 (I think this is because it’s sunny and the solar is charging the battery, to your point about looking at it while dark).
The 3rd reading at the panel reads 12.9

The whole point of this for me was to do a dry run in the driveway to understand the approximate amount of time I can go on just one lithium battery while running various different things such as refrigerator, heat/fan, some lights etc…I realize there are a ton of factors that can influence this but it was just to get a gauge.

If I go by the voltmeter, 13.1 volts left after about 48 hrs, I am sitting at about 40% battery left (according to battery manufacturer manual). I do have one solar 100 watt solar panel, that is probably helping a little bit.

[tomkatb]

Pretty easy.

The max voltage of the battery is around 13.5.

The minimum operating voltage is near 12.

At 13.1 you are about .4/1.5 27% down or at 73% capacity

[Larry-NC]

Originally Posted by mbike254life

I am unplugged from shore power.

AND make sure the solar is disabled. Otherwise you are reading the charging voltage, not the state of the battery.

[boondocking]

tomkatb
The OP's battery manufacters manual says 13,1v = 40% SOC
You are saying 13.1v = 73% SOC

That is quite a difference in SOC

[kenandterry]

From Google…..pick your state of charge

[mbike254life]

Originally Posted by Larry-NC

AND make sure the solar is disabled. Otherwise you are reading the charging voltage, not the state of the battery.

It’s a good point, how would I disable it? Everything is hard wired…solar came preinstallee. There is not switch or mechanism to disable. At least not easily…

[mbike254life]

For reference this is directly from the battery manual. Just FYI.

[tomkatb]

You are correct. The readings from a voltmeter are sort of not linear.

13.1 volts is according to the chart is a 40% charge.

We installed our lithium batteries a few weeks ago.

Fortunately my SOK batteries have a built in monitor. No more looking at the chart. I was surprised how little we used per day using a cpap and the furnace.

According to the monitor about 20 amps dc. Which I think is low.

[mbike254life]

Originally Posted by tomkatb

You are correct. The readings from a voltmeter are sort of not linear.



13.1 volts is according to the chart is a 40% charge.



We installed our lithium batteries a few weeks ago.



Fortunately my SOK batteries have a built in monitor. No more looking at the chart. I was surprised how little we used per day using a cpap and the furnace.



According to the monitor about 20 amps dc. Which I think is low.

So I think I understand the general concept of volts and the readings. But I am still lost when it comes to amps, you said “according to the monitor about 20 amps dc. Which I think is low” - can you explain why you added that? Interested in learning…

[tomkatb]

The monitor in the battery said we were 95% full. 5% of 412 total amps in the battery bank is roughly 20 amps. Seems low to me. Voltage was 13.5.

Power, watts= I, amps times v voltage. P=IV

My batteries are new and I think the meter is goofy until several discharges.

[mbike254life]

Originally Posted by tomkatb

The monitor in the battery said we were 95% full. 5% of 412 total amps in the battery bank is roughly 20 amps. Seems low to me. Voltage was 13.5.



Power, watts= I, amps times v voltage. P=IV



My batteries are new and I think the meter is goofy until several discharges.

Got it. So I have a 100 amp battery. Last question … I have a 2022, that came with the solar package, one thing I just realized is that none of my electrical outlets and my outside mini-fridge do NOT work on battery only? I am assuming that this is intentional to reduce the load on the converter? But wasn’t sure if they should work and are not for a different reason.

[boondocking]

Originally Posted by mbike254life

Got it. So I have a 100 amp battery. Last question … I have a 2022, that came with the solar package, one thing I just realized is that none of my electrical outlets and my outside mini-fridge do NOT work on battery only? I am assuming that this is intentional to reduce the load on the converter? But wasn’t sure if they should work and are not for a different reason.

If the trailer does not come equipped with an inverter the 120 outlets will not work unless you are plugged into a 120 vac source.
The outside fridge may need a 120 vac source.

[pilotpip]

Originally Posted by mbike254life

Got it. So I have a 100 amp battery. Last question … I have a 2022, that came with the solar package, one thing I just realized is that none of my electrical outlets and my outside mini-fridge do NOT work on battery only? I am assuming that this is intentional to reduce the load on the converter? But wasn’t sure if they should work and are not for a different reason.

A converter switches shore power from AC to DC for battery charging and other DC loads. You're confusing that with an INVERTER, which changes DC to AC for things like your fridge, and electrical outlets.

If you have an inverter, it's possible it's going to the fridge. If you don't, and want to run any of the things you mentioned you're going to need one, probably at least 2000w, and you're going to need significantly more amp hours if you want to reliably power them when there isn't much sun to recharge.