Battery question

[ZaneBorry]

Hey guys. I'm making an overland trailer and needed batteries. I don't have the money for those expensive ones and I dont need anything fancy. Just running some led lights inside the trailer, a fridge, and charging phones. I was looking at the Walmart EverStart Lead Acid Marine & RV Deep Cycle Battery, Group Size 29DC or home depots Nautilus 31 Deep Cycle Marine Battery. Would these work? And if so which is better? Any other suggestions for batteries? Thanks

 

[Ubiety]

Yep, a deep cycle battery will work. I use a marine deep cycle battery (~80 or ~100 amp hour) and it will run my fridge and lights for ~3 days from a full charge (without charging). I use it because I already had it and is known to be a good battery; when it dies I'll consider something new/better.
Pros - cheap and works
Cons - heavy, can only use to ~50% discharge w/o damaging it, may leak (suggest sealed or AGM at least if you will be bouncing it around), requires trickle charging when not in use to keep healthy.

How will you charge it on the road and at home? For a trailer (especially in FL) I'd suggest keeping it attached to a solar panel(s) and solar charger at least. That will keep it healthy when not in use (assuming the panels receive sunlight) and will help keep it charged on the road.

 

[Mountaintrails71]

Keep in mind a lead acid battery must NOT be mounted in an area you are going to sleep in. I built my son in law and daughter a square drop a couple years ago and we put a Interstate deep cycle in it. Interstate is my go to brand for everything. They don’t have a fridge but they do run a roof fan all the time and charge their phones and equipment. They have been off grid for a week with no charging and it has worked great.

 

[ZaneBorry]

Yep, a deep cycle battery will work. I use a marine deep cycle battery (~80 or ~100 amp hour) and it will run my fridge and lights for ~3 days from a full charge (without charging). I use it because I already had it and is known to be a good battery; when it dies I'll consider something new/better.
Pros - cheap and works
Cons - heavy, can only use to ~50% discharge w/o damaging it, may leak (suggest sealed or AGM at least if you will be bouncing it around), requires trickle charging when not in use to keep healthy.

How will you charge it on the road and at home? For a trailer (especially in FL) I'd suggest keeping it attached to a solar panel(s) and solar charger at least. That will keep it healthy when not in use (assuming the panels receive sunlight) and will help keep it charged on the road.

I have 2 100 watt solar panels and a charge controller from renogy that I'm mounting on top of the trailer

 

[ZaneBorry]

Keep in mind a lead acid battery must NOT be mounted in an area you are going to sleep in. I built my son in law and daughter a square drop a couple years ago and we put a Interstate deep cycle in it. Interstate is my go to brand for everything. They don’t have a fridge but they do run a roof fan all the time and charge their phones and equipment. They have been off grid for a week with no charging and it has worked great.

No I'm making a serperate tounge box to house the batteries and other electrical items. Could you link me the battery you used? Is it also lead acid?

 

[Ubiety]

I have 2 100 watt solar panels and a charge controller from renogy that I'm mounting on top of the trailer

Make sure the charger supports your intended battery type (and others for the next battery)

 

[reaver]

Interstate has lots of options for deep cycle batteries.

You can also get them from Walmart and Amazon. But before you do, consider the following....

Yes, while LiFePO4 batteries are more expensive up front, they work out to be the same price, or cheaper in the long run than traditional deep cycle batteries.

For example, if you take two 100Ah batteries, one being deep cycle, and the other being lifepo4, you'd be looking at say $300 vs $650.

Now, with the deep cycle, you have a usable range of about 50Ah.

Lifepo4 has about 90Ah usable.

Now, in order to get the same usable energy out of a deep cycle, you'd need at least 180Ah. Those batteries are about $400-600.

Now, deep cycle batteries are good for about 750 charges before they start losing capacity.

LiFePO4 is good for up to 7000 charges. Draining it completely drops that to about 4000 charges.

So, over the life of the $650 battery, you would have to buy 4-5 180Ah deep cycle batteries to give the same amount of energy storage that you get with the lifepo4 battery. That works out to about $2000 or more.

This was the argument I presented my wife with when I decided to go with the lifepo4 battery in the trailer.

Food for thought.

 

[ZaneBorry]

Interstate has lots of options for deep cycle batteries.

You can also get them from Walmart and Amazon. But before you do, consider the following....

Yes, while LiFePO4 batteries are more expensive up front, they work out to be the same price, or cheaper in the long run than traditional deep cycle batteries.

For example, if you take two 100Ah batteries, one being deep cycle, and the other being lifepo4, you'd be looking at say $300 vs $650.

Now, with the deep cycle, you have a usable range of about 50Ah.

Lifepo4 has about 90Ah usable.

Now, in order to get the same usable energy out of a deep cycle, you'd need at least 180Ah. Those batteries are about $400-600.

Now, deep cycle batteries are good for about 750 charges before they start losing capacity.

LiFePO4 is good for up to 7000 charges. Draining it completely drops that to about 4000 charges.

So, over the life of the $650 battery, you would have to buy 4-5 180Ah deep cycle batteries to give the same amount of energy storage that you get with the lifepo4 battery. That works out to about $2000 or more.

This was the argument I presented my wife with when I decided to go with the lifepo4 battery in the trailer.

Food for thought.

Would one lifepo4 battery be enough then to run a fridge 24/7, lights for a couple hours, and to charge phones. It would be connected to 2 100 watt solar panels with a 40a charge controller

 

[North American Sojourner]

I've used Autozone batteries for years, a decade at least. Warranty is good at 3500 stores in the US and Mexico. You want a battery you can get when it craps the bed in the desert. LOL.
I use 100AH AGM's and they're great
Zim

 

[zgfiredude]

For what you describe as the usage of the battery, deep cycle will be fine. Sometimes simple is best....AutoZone, or WalMart is available everywhere if there are any issues on the road. Pop in grab a new one, hit the road. Your thought of 100AH is likely plenty given that you have the solar to boost it daily. Start with one, design for two perhaps and if the needs grow you can add another. I just don't think you'll have an issue with the 1 100AH battery. And there is the "in between" option of an AGM Battery. This is what I chose, for the sealed and mount at different angles ability they offer. They also pack a bit more of a punch power wise. With any choice you have to do SOME watching, monitoring, and caring for them....some a bit more then others.

 

[John and Mandi]

I've run both AGMs and Lithium full time, for a weekend and/or occasional multi week trip rig I recommend AGMs. It is much more of a set and forget it system. Most lithium batteries do not want to be charged every singe day, it's why your smart phone uses built in software to vary the charge and why every now and then it'll state it won't be fully charged until 4AM. Lead acid likes to recover everyday so letting solar top it off is a great way to keep them healthy. Also, the 50% rule is not a great practice and will shorten the battery life considerably (each battery manufacturer has information that states this on their website). It is much better to not use more than 30% really 20%, never dipping below 70% capacity, and making sure they recover almost every day. That being said, starting with a cheaper lead acid and building up from there is usually how everyone does it. Do we get much more out of our lithium, of course, do I think the cost has been entirely justified...no. Maybe if it's still working in 13 years I might change my tune but to think I'm not going to reconfigure my electrical system again in the next decade is ridiculous. We might not even be in this rig and someone may want more than the 150AH we have in it. Like all batteries, you just can't add one at any time. You usually want them to be very close in age.

Personally, I'd make sure there was money in the budget for a solid way to monitor the health of the battery by percentage available/used and not by voltage. Victron makes a Smart Shunt which enables this via Bluetooth (500 amp model is $130 on Amazon), way easier than a traditional negative shunt and a battery monitor that requires special twisted pairs of wires and cryptic programming (coming from experience) and a lot cheaper. Our 200AH AGM, when new, would not be below 94% each morning. Our fridge (40Q Engel) was always on and all of our lights are led. We did charge a phone and one or two tablets almost nightly. We use a tablet to watch movies as they use much less power than a laptop. Our 255Ws of solar usually had us recharged by 11:30 each morning. If you go with 100AH then, using our numbers as an example, you could expect to be around 88% in the morning and you'll recover slightly faster...the trickle part of charging always takes a couple hours. Why many of us end up with larger battery banks is due to inclement weather, something you'll have to determine yourself. For a full 24 hours it's not exactly a doubling of the nightly usage. A rough estimate would be maybe 28% per day. Two days without any charge could have you just under 50% remaining. Should you prepare for that, not sure, but we have friends that wrapped their fridge with blankets and turned it off at night to conserve power. We could just idle the van to add a bit of charge if we were concerned, others used a generator. There are a lot of ways to skin this cat.

We love our fridge but we were full time for 7 years. Now that we've pulled off the road we would have no issue with just using a cooler for a weekend trip (we brought our Engel inside the house and use it as a secondary freezer when needed). Seriously, thick styrofoam coolers like the ones used to ship food work exceptionally well. Wrapped with a blanket we can easily go 3 days on one bag of ice. We also don't refrigerate things like eggs, condiments, etc but we eat normal meals and not camp food. No offense to hotdogs, which are great when camping, but we prefer things like Butter Chicken, Picadillo, Beef and Broccoli, Curries, etc. A really good jump pack would keep our phone and tablets charged and can run usb string lights for a long time. For us, the cost of putting in an electrical system is more than what we'd spend on camping for several years. I know you are at the end stage of putting yours in but I just wanted to say that for anyone else who may use this thread for advice.

 

[reaver]

Would one lifepo4 battery be enough then to run a fridge 24/7, lights for a couple hours, and to charge phones. It would be connected to 2 100 watt solar panels with a 40a charge controller

I have a single 100Ah battery in my trailer. We went for 4 days over memorial day. I expect that I would be able to stay stationary for 3 days at a minimum without having to worry about charging the battery. Now, for that trip, the only thing in the trailer that was using power was the fridge, and the water pump. I've since added camp lights on the trailer, and am currently working on running power up to the RTT to run our cpaps, and charge phones. This will be tested at Overland Expo NW in a few weeks. I have a 20A solar charge controller paired with a 120W solar panel, as well as a 20A DC-DC charger. In less than ideal conditions, the solar setup has so far, managed to keep up. Expo is going to be warmer, which means the fridge will by cycling more, so we'll see how it does there.

I've run both AGMs and Lithium full time, for a weekend and/or occasional multi week trip rig I recommend AGMs. It is much more of a set and forget it system. Most lithium batteries do not want to be charged every singe day, it's why your smart phone uses built in software to vary the charge and why every now and then it'll state it won't be fully charged until 4AM. Lead acid likes to recover everyday so letting solar top it off is a great way to keep them healthy. Also, the 50% rule is not a great practice and will shorten the battery life considerably (each battery manufacturer has information that states this on their website). It is much better to not use more than 30% really 20%, never dipping below 70% capacity, and making sure they recover almost every day. That being said, starting with a cheaper lead acid and building up from there is usually how everyone does it. Do we get much more out of our lithium, of course, do I think the cost has been entirely justified...no. Maybe if it's still working in 13 years I might change my tune but to think I'm not going to reconfigure my electrical system again in the next decade is ridiculous. We might not even be in this rig and someone may want more than the 150AH we have in it. Like all batteries, you just can't add one at any time. You usually want them to be very close in age.

Personally, I'd make sure there was money in the budget for a solid way to monitor the health of the battery by percentage available/used and not by voltage. Victron makes a Smart Shunt which enables this via Bluetooth (500 amp model is $130 on Amazon), way easier than a traditional negative shunt and a battery monitor that requires special twisted pairs of wires and cryptic programming (coming from experience) and a lot cheaper. Our 200AH AGM, when new, would not be below 94% each morning. Our fridge (40Q Engel) was always on and all of our lights are led. We did charge a phone and one or two tablets almost nightly. We use a tablet to watch movies as they use much less power than a laptop. Our 255Ws of solar usually had us recharged by 11:30 each morning. If you go with 100AH then, using our numbers as an example, you could expect to be around 88% in the morning and you'll recover slightly faster...the trickle part of charging always takes a couple hours. Why many of us end up with larger battery banks is due to inclement weather, something you'll have to determine yourself. For a full 24 hours it's not exactly a doubling of the nightly usage. A rough estimate would be maybe 28% per day. Two days without any charge could have you just under 50% remaining. Should you prepare for that, not sure, but we have friends that wrapped their fridge with blankets and turned it off at night to conserve power. We could just idle the van to add a bit of charge if we were concerned, others used a generator. There are a lot of ways to skin this cat.

We love our fridge but we were full time for 7 years. Now that we've pulled off the road we would have no issue with just using a cooler for a weekend trip (we brought our Engel inside the house and use it as a secondary freezer when needed). Seriously, thick styrofoam coolers like the ones used to ship food work exceptionally well. Wrapped with a blanket we can easily go 3 days on one bag of ice. We also don't refrigerate things like eggs, condiments, etc but we eat normal meals and not camp food. No offense to hotdogs, which are great when camping, but we prefer things like Butter Chicken, Picadillo, Beef and Broccoli, Curries, etc. A really good jump pack would keep our phone and tablets charged and can run usb string lights for a long time. For us, the cost of putting in an electrical system is more than what we'd spend on camping for several years. I know you are at the end stage of putting yours in but I just wanted to say that for anyone else who may use this thread for advice.

These are all very valid points, and things to consider.

 

[shansonpac]

I have a single 100Ah battery in my trailer. We went for 4 days over memorial day. I expect that I would be able to stay stationary for 3 days at a minimum without having to worry about charging the battery. Now, for that trip, the only thing in the trailer that was using power was the fridge, and the water pump. I've since added camp lights on the trailer, and am currently working on running power up to the RTT to run our cpaps, and charge phones. This will be tested at Overland Expo NW in a few weeks. I have a 20A solar charge controller paired with a 120W solar panel, as well as a 20A DC-DC charger. In less than ideal conditions, the solar setup has so far, managed to keep up. Expo is going to be warmer, which means the fridge will by cycling more, so we'll see how it does there.

Same in my trailer. I run a Snowmaster 56 on auto, Plenty of string lights, water pump, LEDs all around in and out, gas safety circuit, USB extension cords to the tent to run lights, charge devices, etc. Starting from 100% SOC, by morning I'm usually at 78%. It is no problem if I'm traveling every day as the DC to DC charger keeps everything topped off. If I stay two nights in one spot, I deploy the 90W Zamp solar. All controllers (DC, Solar and 110v) are Victron. My trailer stays plugged in at home, and the 110v controller goes into Storage mode when fully charged to keep the battery healthy. I have been very happy with battery performance.

I will be at PNW Expo too, and will keep my solar deployed as I will be overnighting for 3 nights. It is like gas. Don't pass a gas station with less than a half tank. You never know what the weather will be so I like to keep my battery topped off. Hope to see you and other OB folks there.

 

[MOAK]

I’m completely different and it works well for us- Our vehicle is the power source. Two AGM batteries under the hood, Two solar panels, one fixed, the other portable, 100watts each. A Renogy charge controller. Two fridge freezers, big one for refrigeration the little one mounted where the consol was for freezing. Two 110 volt water pumps, one low pressure aquarium pump in the trailer for kitchen water, the other high pressure is mounted on the truck for showers. The vehicle is the power source, the trailer plugs into power inverter for all power. We run a line up into the tent to keep phones and usb lanterns charged up. The power of twos works well for us. I’ll keep using AGMs until the front cost of lithiums and setting up a DC-DC charger becomes competitive with what I have. With the two battery system and two solar panels we can shower, pump kitchen water, charge up the camera batteries, and keep two fridges running indefinitely. An additional benefit? Ever check the price of a 12 volt water pump versus the 110s? The aquarium pump was only $35 and it is freeze proof. Just my thoughts- peace out

 

[reaver]

I’m completely different and it works well for us- Our vehicle is the power source. Two AGM batteries under the hood, Two solar panels, one fixed, the other portable, 100watts each. A Renogy charge controller. Two fridge freezers, big one for refrigeration the little one mounted where the consol was for freezing. Two 110 volt water pumps, one low pressure aquarium pump in the trailer for kitchen water, the other high pressure is mounted on the truck for showers. The vehicle is the power source, the trailer plugs into power inverter for all power. We run a line up into the tent to keep phones and usb lanterns charged up. The power of twos works well for us. I’ll keep using AGMs until the front cost of lithiums and setting up a DC-DC charger becomes competitive with what I have. With the two battery system and two solar panels we can shower, pump kitchen water, charge up the camera batteries, and keep two fridges running indefinitely. An additional benefit? Ever check the price of a 12 volt water pump versus the 110s? The aquarium pump was only $35 and it is freeze proof. Just my thoughts- peace out

I managed to score my pump for free, as it came out of an old RV that a friend of mine scrapped.

This illustrates the point that was made earlier, as there's many different ways to go about solving the electrical conundrum when it comes to off-grid trailers.

Your method works well for you, my method so far is working very well for us. Neither is right or wrong. OP will need to think through how they're planning on using their setup, and figure out how to set up the system to suit their needs.

 

[M Rose]

Hey guys. I'm making an overland trailer and needed batteries. I don't have the money for those expensive ones and I dont need anything fancy. Just running some led lights inside the trailer, a fridge, and charging phones. I was looking at the Walmart EverStart Lead Acid Marine & RV Deep Cycle Battery, Group Size 29DC or home depots Nautilus 31 Deep Cycle Marine Battery. Would these work? And if so which is better? Any other suggestions for batteries? Thanks

The batteries you listed will work just fine, I run a pair of the Walmart EverStart Group 29 batteries in both my Bronco and in my boat… the ones in my Bronco have been in constant use since 2014. The boat batteries are about 4 years old… both sets are going strong.

 

[MOAK]

Your method works well for you, my method so far is working very well for us. Neither is right or wrong. OP will need to think through how they're planning on using their setup, and figure out how to set up the system to suit their needs.

Absolutely true, which is why it can be so confusing for a newbie to all things electrical.