Looking to maintain the batteries....

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Just brainstorming here but what if you got either a battery charger or solar to charge the batteries and added something on a timer to use some of the power. Not sure what i would put on the timer but wouldnt that address both issues?

Starting the truck once a month might be easier though
 
Just brainstorming here but what if you got either a battery charger or solar to charge the batteries and added something on a timer to use some of the power. Not sure what i would put on the timer but wouldn't that address both issues?

Starting the truck once a month might be easier though
That may be a good idea but might also be a drain with how small my panel is. If the solar system was bigger....
 
That may be a good idea but might also be a drain with how small my panel is. If the solar system was bigger....
as long as you set the drain to be less than the solar puts back in theory it should work. I don't know how much you have to draw down a battery to avoid issues and that would factor in by a large amount. You have a large battery bank so the draw would have to be bigger. Solar isn't fast but I love it cause once you have it it works for a very long time.
 
So, here is an update.

The truck has all new batteries. Four 31 series commercial hooked in Parallel.

Went thru the battery box wiring and the truck now has one disconnect switch for both of the 12v+ for the ECM circuit.

It has another disconnect switch for the Battery to frame ground and inverter/diesel heater ground.

The other cables are connected to the batteries. There are 3 positives and 1 ground cable.

To completely isolate the batteries from the truck, just turn the 2 switches off and disconnect the ground from the batteries that goes to the starter. Yes, the starter has both positive and negative connections on it.

Now, here is where my question is answered.
When I got the batteries installed 100%, they were reading 12.56 volts.
With being disconnected from the truck, 3 hours later, they were reading 12.60 volts.
This point to the fact that the solar panel is big enough to float charge this big battery set up.

Next test?
See if the solar system is good enough to maintain the batteries with the starter negative still connected but the 2 switches turned off.

But right now, thigs are looking good. :)
 
2 of the batteries were from 2020, 2 others were from 2022.
The 2 from 2020 were with the truck when I bought it.
The previous owner stated he always had to charge the batteries before each use if the truck sat for a little while. Hence, a drain somewhere.
The charger is a programmable one (but still a cheap one) and I have it set to maintain the batteries at 12.8 volts.

I'll let it sit for a day this way and see what it does. Then, I'll run the diesel heater for a night and see what it does to the charge. Would rather test it here in the driveway than in BFE with no way to replenish the charge on the battery bank. :)
 
that doesn't sound very long for a set of batteries. Makes me think the battery monitor would help a lot. The main benefit of them is helping you manage the batteries better to extend the life.

If you have the luxury the best option is to get the charge recommendations for the batteries from the manufacturer and having a charger that you can set to those exact specs.

There are some issues with mixing batteries and having different ages but I'm not very familiar with those. Others here know a lot more about that so hopefully they see this and respond. Wondering if the age mix is contributing to reduced battery life.
 
that doesn't sound very long for a set of batteries. Makes me think the battery monitor would help a lot. The main benefit of them is helping you manage the batteries better to extend the life.

If you have the luxury the best option is to get the charge recommendations for the batteries from the manufacturer and having a charger that you can set to those exact specs.

There are some issues with mixing batteries and having different ages but I'm not very familiar with those. Others here know a lot more about that so hopefully they see this and respond. Wondering if the age mix is contributing to reduced battery life.
These are all new batteries, all the same part number and size. They were installed today.

General rule of thumb for all lead acid batteries is storage at 12.6 - 12.8 VDC. It would be hard pressed to find a lead acid manufacturer to recommend more, or less than that for maintenence/trickle charge.

You, yourself said that if the batteries are part of the vehicle run/charge system, a monitor probably wouldn't do any good.
These batteries are ultimately the main starting batteries for the truck. All the extra stuff in the truck are items I added.

My use of the truck doesn't warrant a battery monitoring system.

My main focus is battery maintenance while in dormant storage. A properly functioning solar controller will do this with nearly 100% efficiency and will keep the batteries ready to use at any moment. If the system is not being checked/monitored on a regular basis, a monitor system would actually be a waste of money IMHO.

If this controller takes the batteries to a healthy 12.6 - 12.8 and holds them there, the solar controller is a perfect monitor system for dormant periods
 
Like I said before, It would take a lot for me to drain over 1700 A/hr of juice with an overnight trip.

Monitoring the usage really isn't an issue
 
not trying to dispute what you are saying. You k ow your situation and i dont. But personally i find as much value from the bmk when i am not using the rv as much as when i do use it.

General rule of thumb for all lead acid batteries is storage at 12.6 - 12.8 VDC. It would be hard pressed to find a lead acid manufacturer to recommend more, or less than that for maintenence/trickle charge.
every battery i ever had as a house battery in an rv specified far higher voltage at certain parts of the charging pattern, as high as 14.4v. That may only be important in charging them as quickly as possible. Your situation is very different and it may not matter.

I dont consider myself a battery expert. I know a bit more than enough to be dangerous and what i dont know is still a lot more than that. Interesting conversation. I learned a few things
 
not trying to dispute what you are saying. You k ow your situation and i dont. But personally i find as much value from the bmk when i am not using the rv as much as when i do use it.


every battery i ever had as a house battery in an rv specified far higher voltage at certain parts of the charging pattern, as high as 14.4v. That may only be important in charging them as quickly as possible. Your situation is very different and it may not matter.

I dont consider myself a battery expert. I know a bit more than enough to be dangerous and what i dont know is still a lot more than that. Interesting conversation. I learned a few things
Just some food for thought....
In my 30 years of dealing with semis, I've never seen battery monitors come stock from the factory in any semi truck. Custom trucks, yes. Never bone stock though.

You also don't see solar panels on semi trucks, but mine has one.

When I use this truck, I run it more down the hwy than I have it parked. While it's moving, it's charging these batteries with the alternator, which renders the solar panel useless. This is why a monitoring system doesn't work for a vehicles main batteries.

Like I said, battery monitoring systems are great for RV uses. Not necessarily practical for semi truck use during long periods of dormancy. Unless you are stopping to check the battery status every day as you walk by it.

I just don't see the practicality of using a monitor system when you have a solar charge controller already monitoring the same exact system.

Overloads or malfunction? That's what fuses are for.
 
They arent common oem equipment on rvs either but i think they should be standard there
Most RV's have a battery level monitor built into the panel you check the fresh and black water tanks with. Granted, these are just voltage testers and just give a basic showing of voltage level, but to be honest, a lot of people travelling in RV's don't even know where the batteries are in their RV, let alone know what they would be monitoring with a true monitor.

That's great that you like them and know what you are looking at, but it could be considered helicopter parenting for your RV. Just over monitoring constantly and expecting something wrong to happen.
But it's easy to tell when your lights get dimmer and know you have a problem.

And yes, a good monitor would tell you which battery is giving a fit in your system, but that will cost $$$. If you want the app on your phone so you can monitor it while away, that's $$$$.

I'm perfectly happy with opening the side door, looking at the cheap solar controller, seeing if the voltage is where it should be, starting it once a month and calling it good. But I also have the knowledge and tools to test the batteries and see why there is a problem when it arrives.

For my situation, a complete system battery monitor system just doesn't make sense, pound per pound.
But if I was living in an RV and boondock alot, and depend on the batteries 90% of the time, then it would make sense.
 
The voltage meters they include are highly innacurate and basically useless. Bmks are not. The rv industry decided to include a way to monitor batteries. Using something that works is the reason i think bmks should be standard. I dont consider that helicopter parenting.
 
But, if someone truly wants to monitor their batteries, you could do what my buddy did.
Get the smart lithium ion batteries for your rig and bypass any kind of monitoring system.
The battery itself connects to your phone thru an app, tells you input, output, current draw, battery voltage, remaining charge left, time left until next charge needed, etc.

Granted, 4 of them batteries for my truck would be $10k, but if you truly want to see what each battery is doing, might as well go straight to the source for the information...
 
In our MH I wired in a small panel D.C. voltmeter to watch the house battery voltage... just a small step up from those four 'idiot' light panel lights but don't get me wrong, those still serve a purpose.
For the chassis battery I plugged in a voltmeter/USB power thing into the powerpoint. All I need to do is monitor both voltages with a glance and if the battery disconnect for either is turned off, the respective voltmeter shows that. I know the condition my batteries and if the regular voltage deviates any, somethings up. That is all I require.

A proper monitor in your system would need a shunt for each battery, just extra crap to corrode/go wrong and it needs to be sized for the expected current usage.
If you can find a clamp-on D.C. amp meter, it would be interesting to find the cold cranking amps your unit experiences.
 
The voltage meters they include are highly innacurate and basically useless. Bmks are not. The rv industry decided to include a way to monitor batteries. Using something that works is the reason i think bmks should be standard. I dont consider that helicopter parenting.
While camping, how many times a day do you look at your monitor system? If you check it, just to check it, that is helicopter monitoring.

If you only check your monitor when you suspect there is a problem, that would be normal.

Just MHO
 
In our MH I wired in a small panel D.C. voltmeter to watch the house battery voltage... just a small step up from those four 'idiot' light panel lights but don't get me wrong, those still serve a purpose.
For the chassis battery I plugged in a voltmeter/USB power thing into the powerpoint. All I need to do is monitor both voltages with a glance and if the battery disconnect for either is turned off, the respective voltmeter shows that. I know the condition my batteries and if the regular voltage deviates any, somethings up. That is all I require.

A proper monitor in your system would need a shunt for each battery, just extra crap to corrode/go wrong and it needs to be sized for the expected current usage.
If you can find a clamp-on D.C. amp meter, it would be interesting to find the cold cranking amps your unit experiences.
I do have a clamp meter and on a cold day, like this morning at 8° and hasn't run for a few days, the highest amperage draw I have seen is 1780 amp surge from the batteries.

On a warm day, 800 amp draw is pretty normal
 

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