Cause of battery drain

[68camaro]

Hello, newbe here, bought Chinook late summer. I have two relatively new group 27 batteries in camper that were checked and filled with water, they were really low, new smart solenoid just installed that feeds from engine battery plus a 45watt solar panel.

When I use the batteries, the voltage meter starts at 12.7 but drops very quickly, I can go from 12.7 to 12.3 in 20 minutes with only one light on that has two 13 watt flouro bulbs and the water pump. The TV, camper radio and vcr are off but their power lights like lighted so there may be parasidic draw here.

Any ideas why my batteries are draining so quickly?

Thanks

 

[luthj]

I would check to see what your amp draw is. Its possible you have a high current device or power usage somewhere.

However, what you describe is likely classic capacity loss due to sulfation. You can try a recovery charge to see if you can get some capacity back. Fully charge the batteries for at least 12 hours at 14.6V@75F. For lower temps you need to up the voltage unless your charger is temp compensated. After 12 hours, do an equalize at 16v for a few hours. You can check the state of charge with a hydrometer through the fill ports. Then put a 25A load on the batteries and record how long it takes for them to drop to 10.5V. Compare to the new value.

To take a shortcut. It is likely your solar charger is not charging your batteries properly, and you likely need a lot more solar, or a good shore power charger. Your batteries are probably not real deep cycle batteries, and will perform poorly in that application. Consider a set of deka/duracell GC2 batteries for 220AH at 12V.

 

[68camaro]

Thanks luthj, I am in beginning of learning about battery/electronics/solar and planning to upgrade solar plus other components. I do not think they are real deep cycle batteries.

Last month I had local RV place test batteries, their testing included: Battery System Check: Includes inspection of battery and water levels, as well as terminal cleaning and hydrometer testing. They reported batteries were really low on water but fine now, they also found smart solenoid/battery seperator was bad so it was replaced. I can hook up to house tomorrow and let charge overnight.

How do I check for AMP draw? I have a multi-meter but admittidly only use it to test battery voltage.

 

[luthj]

Most multi meters are limited to 10A. So for currents 10A and under. Switch your meter to Amps measurement. Move the probes from the voltage to current/amps port on the meters front face. Connect the meter so that it is part of the load circuit. So you can disconnect the negative OR positive and complete the circuit with the meters probes. Another option is to remove the fuse and use the meter to bridge the fuse terminals. Be careful not to bend the fuse socket pins. Do not bridge the positive and negative wires at the same time in Amps mode. Unlike the voltage mode, in amps mode doing this will cause a short circuit and blow the meters internal fuse.

While you are charging your batteries, periodically check the voltage at their terminals. This will help you determine if your chargers are doing what they should. After 1-4 hours, the voltage should climb to at least 14.4V, and it needs to stay there for at least 2 hours ideally.

 

[workerdrone]

Instantaneous voltage readings often drop very quickly and indicate voltages far below the actual (resting) voltage that you'd read if you disconnected the batteries and let them rest for a while. I've seen 12.7 (100% charge basically) go well into the 11's while running a bigger load like a microwave, then come right back up to 12.7 when they have time to recover. With no input whatsoever.

Also can make a big difference where the reading is being taken.

There are a lot of possibilities here, you may have too much draw robbing you of efficiency, the batteries may not be in as good shape as you think, or you may not be reading anywhere near the actual voltage when you read that 12.3.

I'd suggest loading them up the same way (normal nighttime usage), then disconnect the bank entirely for an hour. See what reading you get directly on the bank after that, should be real close to actual. Your 12.3 might go back to 12.6 or something.

I'd probably also want to make sure anything I'm not using is completely disconnected - TV, radio, vcr able to be switched off completely.

45 watts is not much solar but if you are driving every day with a good alternator charge connection it might be fine. Really depends on your daily patterns.

And if you find your 27's are not actually in good shape, I'd think about replacing later with dual 6v golf cart batteries if you want to keep on a lower budget / bang for the buck...also LED lights instead of fluoro

 

[john61ct]

Batteries likely shot.

Age is irrelevant when abused badly enough.

Ensure you're caring for the new bank better, can last 8+ years

 

[68camaro]

I just checked on rig and with engine off, voltage on meter and at each battery tested with multi-meter was 11.7. When I started van voltage at meter and at both batteries jumed to high 13's then 14.00 immediately.

***What does "Array Current" mean on Applied Power Mark 15 meter mean? It read -7.4 or -7.6???

The batteries are Super Smart Marine Deep Cycle: https://www.oreillyauto.com/detail/...-size-27-top-post-battery/27dcm/4742400?pos=0
Not sure if these are decent batteries or not.

Most multi meters are limited to 10A. So for currents 10A and under. Switch your meter to Amps measurement. Move the probes from the voltage to current/amps port on the meters front face. Connect the meter so that it is part of the load circuit. So you can disconnect the negative OR positive and complete the circuit with the meters probes. Another option is to remove the fuse and use the meter to bridge the fuse terminals. Be careful not to bend the fuse socket pins. Do not bridge the positive and negative wires at the same time in Amps mode. Unlike the voltage mode, in amps mode doing this will cause a short circuit and blow the meters internal fuse.

I will try this Saturday, in meantime I am watching youtube videos on reading amps, your description is very helpful.

There are a lot of possibilities here, you may have too much draw robbing you of efficiency, the batteries may not be in as good shape as you think, or you may not be reading anywhere near the actual voltage when you read that 12.3.

I'd suggest loading them up the same way (normal nighttime usage), then disconnect the bank entirely for an hour. See what reading you get directly on the bank after that, should be real close to actual. Your 12.3 might go back to 12.6 or something.

I'd probably also want to make sure anything I'm not using is completely disconnected - TV, radio, vcr able to be switched off completely.

45 watts is not much solar but if you are driving every day with a good alternator charge connection it might be fine. Really depends on your daily patterns.

And if you find your 27's are not actually in good shape, I'd think about replacing later with dual 6v golf cart batteries if you want to keep on a lower budget / bang for the buck...also LED lights instead of fluoro

I'll unplug everything I can and see if that helps. The 45 is probably fine but I do want to upgrade and at Overland East I hope to find solar company that can help me select best panels for needs. I don't have problem getting new batteries and can get best there is, if I do need new I'll ask what is best, marine, agm or golf cart. Price is secondary concern.

Right now I can only turn on digital HD channel via generator or shore power, is it reasonavle to think a battery bank can run the digital tv antenna?

 

[luthj]

We need to know your needs before we make detailed recommendations. The more detail the better. A small to medium battery bank should have no problem running an LED TV etc. If your existing TV doesn't have an internal HDTV antenna it is probably pretty old and inefficient. Switching to a newer 12VDC native LED backlit TV will save a fair bit of power.

Array amps usually means the AMPs the solar controller is outputting. I am not sure what negative amps would mean. It could means a load of 7.4 amps?

The best bang for your buck is the GC2 golf cart batteries mentioned (about 200$). But every persons needs and install are different.

Good quality solar panels can be had cheap. Grape solar panels are sold by Home depot, Amazon etc, and are sometimes on special for less than $1.30 a watt. More important than the panels, is a controller that is programmed to meet your batteries charge needs. 99% of the charge controllers on the market go to float way to early, and will shorten battery life. The good ones can be programmed/adjusted to correct this.

 

[68camaro]

We need to know your needs before we make detailed recommendations. The more detail the better. A small to medium battery bank should have no problem running an LED TV etc. If your existing TV doesn't have an internal HDTV antenna it is probably pretty old and inefficient. Switching to a newer 12VDC native LED backlit TV will save a fair bit of power.

Array amps usually means the AMPs the solar controller is outputting. I am not sure what negative amps would mean. It could means a load of 7.4 amps?

The best bang for your buck is the GC2 golf cart batteries mentioned (about 200$). But every persons needs and install are different.

Good quality solar panels can be had cheap. Grape solar panels are sold by Home depot, Amazon etc, and are sometimes on special for less than $1.30 a watt. More important than the panels, is a controller that is programmed to meet your batteries charge needs. 99% of the charge controllers on the market go to float way to early, and will shorten battery life. The good ones can be programmed/adjusted to correct this.

I just started putting need list together with watts of current appliances/lights etc on rig. so I can get correct sized/scoped system. The TV was brand new in 2001 so pretty old...haha. Upgrade will be part of my complete electrical/solar upgrade project.



Once I check batteries/recharging and get needs down I'll definitely be back looking for specific suggestions. I guess right batteries will depend on complete system needs.

Thank you.

 

[68camaro]

I would check to see what your amp draw is. Its possible you have a high current device or power usage somewhere.

On a two battery bank systen, can I check amp draw by just taking positive off one battery, or do I need to disconnect both terminals from second battery to get correct reading?

 

[luthj]

You would need to check with both positives disconnected. Otherwise you won't be measuring the current coming from the other battery

 

[68camaro]

You would need to check with both positives disconnected. Otherwise we will be measuring the current coming from the other battery

Great thank you.

 

[john61ct]

Multiple batts connected together into a single bank should be treated as one big bank.

Only need to break it up for testing or maintenance procedures, like some need equalizing.

 

[workerdrone]

^well, yes, but we're talking about testing here, so I'd test the batteries separately. If one of them is damaged it'll drag the whole bank down.

This does sound like a situation where the camper was plugged into shore power for longterm storage with an unsophisticated charger and boiled the batteries dry. My guess, but without more data we dunno

Get all the data and learn about your components and configuration before throwing any $ at the rig I'd say

 

[68camaro]

Thanks all, well here's were we are.

Yesterday drove 5 hours with coach battery charger "on", got home and plugged RV into house for 12+ hours. This morning coach showed only 13.8 volts. Unplugged from house and within one hour it drained to 11.8 and low battery alarm went off.

Did parastic drain test on each battery. Disconnected positive from both batteries. With coach electrical switched to off, battery "A" had amp load of .08. Baterry "B" had no reading. Turned coach electricity back on but turned everthing off and battery "A" maintained .08 amp draw, battery B still registered nothing.

Check fluid levels with Mini Meter with balls in it, Battery "A" had one cell at 75%, battery "B" had several cells at 75% and one needed water. These were all filled a month ago with little usage since.

Do you think batteries are bad, or could there be another reason. I do have a new 100ah AGM battery I use as house battery in Jeep, I can replace one of the batteries with this one if it will help.

I have business trip Tue and Wed and I leave early Thursday for Overland East so I have little time to correct this but any help appreciated. I was hoping to get new solar setup at Overland East but it will stink being there without batteries working, so I may have to focus on getting this worked out.