christina011090
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Post by christina011090 on Mar 15, 2017 10:15:12 GMT -8
So I was researching batteries (location inside versus outside & amp draw specifically) and I came across a thread from a couple of years ago where mobiltec mentioned a battery from Harbor Freight that was great to work with. So... 1) Larry: is this the battery? Do you still recommend it and is it truly safe without venting or a sealed battery compartment? I assume better safe than sorry in this case though. www.harborfreight.com/12-volt-35-amp-hour-universal-battery-68680.html2) I see it only seems to come in the 35aH capacity. I did a rough calculation of the amp-hours I expect to pull over a 24 hour period while dry camping and I was hoping you all might be able to tell me if I'm in the right ballpark. I like to think I may not need quite this much but trying to be safe. I'd like to know if I'm missing anything significant or if I'm a bit high. (4) LED lights @ 1amp/4 hours = 16aH Water Pump @ 6amps/1 hour = 6aH Water Heater @ 1amp/1 hour = 1aH Fridge (6 cu. ft Dometic, propane) = 9aH at lowest setting Fantastic Fan @ 2amps/6 hours = 12aH at highest setting CO Detector = 3aH Radio @ 4amps/2 hours = 8aH Laptop @ 4amps/4 hours = 16aH Total: 71aH x2 (to account for no less than 50% battery depletion) = ~140aH = (4) Harbor Freight 35aH Batteries
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mobiltec
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Post by mobiltec on Mar 15, 2017 14:42:42 GMT -8
So I was researching batteries (location inside versus outside & amp draw specifically) and I came across a thread from a couple of years ago where mobiltec mentioned a battery from Harbor Freight that was great to work with. So... 1) Larry: is this the battery? Do you still recommend it and is it truly safe without venting or a sealed battery compartment? I assume better safe than sorry in this case though. www.harborfreight.com/12-volt-35-amp-hour-universal-battery-68680.html2) I see it only seems to come in the 35aH capacity. I did a rough calculation of the amp-hours I expect to pull over a 24 hour period while dry camping and I was hoping you all might be able to tell me if I'm in the right ballpark. I like to think I may not need quite this much but trying to be safe. I'd like to know if I'm missing anything significant or if I'm a bit high. (4) LED lights @ 1amp/4 hours = 16aH Water Pump @ 6amps/1 hour = 6aH Water Heater @ 1amp/1 hour = 1aH Fridge (6 cu. ft Dometic, propane) = 9aH at lowest setting Fantastic Fan @ 2amps/6 hours = 12aH at highest setting CO Detector = 3aH Radio @ 4amps/2 hours = 8aH Laptop @ 4amps/4 hours = 16aH Total: 71aH x2 (to account for no less than 50% battery depletion) = ~140aH = (4) Harbor Freight 35aH Batteries
I've only used these batteries for very limited loads like lighting and maybe a small water pump. I think a larger sealed battery would be better for your needs and probably a little less expensive than for of these batteries. Also you won't have all that extra wiring to do. I think one batter vs 4 would be safer also. So search around for a sealed battery that will fill your needs or two 6v batteries that installed in series would make 12vdc and fill your ampere/hour needs.
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Post by vikx on Mar 15, 2017 21:20:50 GMT -8
Any kind of battery should be in an enclosed vented compartment or outside. Do not be fooled by manufacturer's claims of "no gassing". They can and do. This comes to mind: The battery was 6 months old, new maintainer and still exploded. Replaced by the seller, but still. Do you want to sleep over THAT???
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christina011090
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Post by christina011090 on Mar 17, 2017 11:42:44 GMT -8
I'm currently looking at a Trojan Battery T-1275 with Master Vent, if anyone is familiar. It sits just at the amount of amp hours I was looking for requiring only one battery. It seems typical for people to have two batteries - is this for the double 6v setup (longer battery life?) or just for additional capacity? This seems to be adequate unless I'm missing something which is definitely possible. www.trojanbattery.com/pdf/datasheets/T1275_Trojan_Data_Sheets.pdf
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royboyprods
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Post by royboyprods on Mar 17, 2017 19:11:20 GMT -8
I'm going with 2 6V 104ah batteries and 200W of solar on my camper. Going that route because 95% I foresee me boondocking away from hookups. Most of my travels will not have convenient campgrounds. So I'm probably not the normal use case. I wanted to run my roof fan and my cpap machine all night plus charge phone, etc.
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ruderunner
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Post by ruderunner on Mar 18, 2017 5:18:31 GMT -8
(4) LED lights @ 1amp/4 hours = 16aH Water Pump @ 6amps/1 hour = 6aH Water Heater @ 1amp/1 hour = 1aH Fridge (6 cu. ft Dometic, propane) = 9aH at lowest setting Fantastic Fan @ 2amps/6 hours = 12aH at highest setting CO Detector = 3aH Radio @ 4amps/2 hours = 8aH Laptop @ 4amps/4 hours = 16aH Total: 71aH x2 (to account for no less than 50% battery depletion) = ~140aH = (4) Harbor Freight 35aH Batteries Read more: vintagetrailertalk.freeforums.net/post/new/8169#ixzz4bgOXKxq9just looking over your list hereand have a couple questions and comments. Do LED lights really pull taht much power? Thought they'd be much lower. Water pumps only run a few seconds at a time unless showering. The amp draw sounds right but the time on sounds way high. Electric water heater will likely pull closer to 10 amps unless you're referring to a propane unit. Not sure the CO detector would be that high either, many run off a single 9 volt for months at a time.
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mobiltec
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Post by mobiltec on Mar 18, 2017 8:55:38 GMT -8
You do NOT want to plan on running ANYTHING on your 12vdc system that create's heat. It will suck your batteries dry in no time at all. They just can not handle the load. So no electric water heaters, hot plates, space heaters or crokpots. It just won't work.
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christina011090
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Post by christina011090 on Mar 18, 2017 10:56:13 GMT -8
ruderunner, I was basing the water pump load on intermittent needs and showering and the water heater will indeed be propane. As for the LED lights I think you're right and I misunderstood the calculation.
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christina011090
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Post by christina011090 on Mar 18, 2017 11:01:10 GMT -8
I spent the earlier part of today at an RV shop nearby. The guy there previously helped me with some plumbing issues I ran into and I asked if he could walk me through some of the electrical system. I'll likely end up sourcing that work out to them, really great people and patient with me so that's a virtue. I think I finally got my head wrapped around it well enough for what I need to know. One thing I learned was the difference between 6V and 12V batteries. It all depends on application but they said their shop has ripped more than a handful of 6V batteries out of campers due to breakage at low temperatures. Even 30 degrees was a cause for concern so they have to be put away when temperatures start to drop, and they said their finicky nature outweighs the benefit in this case.
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cowcharge
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Post by cowcharge on Apr 9, 2017 7:54:56 GMT -8
Hi, Christina. Sorry to be blunt, but they're just outright wrong about 6v batteries being any more fragile than 12v. More like the opposite. 6v batteries (at least, real deep cycle ones) are made much more robust than the typical 12v batteries people buy (car batteries and so-called "marine" batteries), because they're made to be used in heavier-duty equipment like golf carts that need a lot of guts and have long, slow discharge and charge rates like we have in campers. If they've seen a lot of bad ones it's due to lack of maintenance/bad installation/faulty equipment/abuse. Normal, below-the-Arctic-Circle cold does not hurt a battery if it's kept charged. If you just let them sit there uncharged all winter, yeah it'll do 'em in eventually. But my four, cheap Duracell EGC2 6-volters from Sam's Club have been sitting in a mostly unused and unheated camper for three Maine winters (so far) without a hitch, because they're on constant, temperature-compensated solar charging. In my four batteries, I add a total of maybe three quarts of distilled water every four months or so. I don't check them that often, and they've never lost enough water to get close to the tops of the plates. Basically, they are maintenance-free. Some other things to consider: The more you bounce your batteries around, the more you need better batteries. It's how well the cells are connected internally. My friendly solar expert HandyBob ranks them, in descending order of quality, Crown, Trojan, Deka (who make my Duracells in PA), and lastly, Interstate. I'm rubber-mounting mine to help lessen the vibration. On top of a squishy-but-firm rubber mat-for-standin'-on-at-work from Lowes. A single 12v battery has to weigh about the same as the two 6-volters to get the same capacity, sometimes more. Which means you might have to move a 120lb battery around instead of two 60-pounders... And a sealed battery weighs more per amp-hour than a wet battery. All batteries need to be vented. All lead-acid batteries gas when being charged, the chemistry is no different if it's sealed. They avoid gas reaching pressures that would burst the battery by lowering the charging voltage to make for less gassing, which means slower charging, a big disadvantage if you're depending on limited sunlight for charging, or you don't want to run the generator twice as long. It also means that you have to match the charger more carefully than you do for "wet" batteries. Most chargers and converters don't even work at high enough voltages or for long enough to properly charge a wet battery, so overcharging them with a converter or charger is hard to do (which admittedly has its own problems when using a converter). Sealed batteries are the finicky ones, though. Sealed batteries are not "maintenance-free", they are "maintenance-prevented." You cannot test the state of charge by sticking a hydrometer in the acid, which is the only truly accurate way to test charge. A voltage check is a very rudimentary check and potentially very innaccurate, because the voltage of a battery fluctuates depending on whether it's being charged or not, or even how long it's been since it reached full charge. And you can't add any water when they need it, all you can do is use them until they fail. The cost per amp-hour for sealed batteries is way higher, and they provide less capacity per-pound. The only time I could see them being a good choice in a camper is if you had to mount them sideways or something.
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christina011090
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Post by christina011090 on Apr 16, 2017 3:55:30 GMT -8
Hi, Christina. Sorry to be blunt, but they're just outright wrong about 6v batteries being any more fragile than 12v. More like the opposite. 6v batteries (at least, real deep cycle ones) are made much more robust than the typical 12v batteries people buy (car batteries and so-called "marine" batteries), because they're made to be used in heavier-duty equipment like golf carts that need a lot of guts and have long, slow discharge and charge rates like we have in campers. If they've seen a lot of bad ones it's due to lack of maintenance/bad installation/faulty equipment/abuse. Normal, below-the-Arctic-Circle cold does not hurt a battery if it's kept charged. If you just let them sit there uncharged all winter, yeah it'll do 'em in eventually. But my four, cheap Duracell EGC2 6-volters from Sam's Club have been sitting in a mostly unused and unheated camper for three Maine winters (so far) without a hitch, because they're on constant, temperature-compensated solar charging. In my four batteries, I add a total of maybe three quarts of distilled water every four months or so. I don't check them that often, and they've never lost enough water to get close to the tops of the plates. Basically, they are maintenance-free. Some other things to consider: The more you bounce your batteries around, the more you need better batteries. It's how well the cells are connected internally. My friendly solar expert HandyBob ranks them, in descending order of quality, Crown, Trojan, Deka (who make my Duracells in PA), and lastly, Interstate. I'm rubber-mounting mine to help lessen the vibration. On top of a squishy-but-firm rubber mat-for-standin'-on-at-work from Lowes. A single 12v battery has to weigh about the same as the two 6-volters to get the same capacity, sometimes more. Which means you might have to move a 120lb battery around instead of two 60-pounders... And a sealed battery weighs more per amp-hour than a wet battery. All batteries need to be vented. All lead-acid batteries gas when being charged, the chemistry is no different if it's sealed. They avoid gas reaching pressures that would burst the battery by lowering the charging voltage to make for less gassing, which means slower charging, a big disadvantage if you're depending on limited sunlight for charging, or you don't want to run the generator twice as long. It also means that you have to match the charger more carefully than you do for "wet" batteries. Most chargers and converters don't even work at high enough voltages or for long enough to properly charge a wet battery, so overcharging them with a converter or charger is hard to do (which admittedly has its own problems when using a converter). Sealed batteries are the finicky ones, though. Sealed batteries are not "maintenance-free", they are "maintenance-prevented." You cannot test the state of charge by sticking a hydrometer in the acid, which is the only truly accurate way to test charge. A voltage check is a very rudimentary check and potentially very innaccurate, because the voltage of a battery fluctuates depending on whether it's being charged or not, or even how long it's been since it reached full charge. And you can't add any water when they need it, all you can do is use them until they fail. The cost per amp-hour for sealed batteries is way higher, and they provide less capacity per-pound. The only time I could see them being a good choice in a camper is if you had to mount them sideways or something. Blunt is good! Thank you for the perspective. I am in midst of getting things settled and will have to follow up. I do want the batteries on the interior, so the loose plan is (2) 12V batteries, each 120 amp hours. I can't recall the weight but they weren't as large as I'd anticipated. I'll have to update when all is said and done. And I've been using this calculator to give an estimate of what I'll need: tools.carmanah.com/src.web/GoPowerCalculator.htm?state=RvDiv&_ga=1.111188740.1693736096.1492303916
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mrmarty51
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Post by mrmarty51 on Apr 16, 2017 12:21:03 GMT -8
Any kind of battery should be in an enclosed vented compartment or outside. Do not be fooled by manufacturer's claims of "no gassing". They can and do. This comes to mind: The battery was 6 months old, new maintainer and still exploded. Replaced by the seller, but still. Do you want to sleep over THAT??? Any time a battery is charged or discharged, it produces hydrogen gas. Hydrogen gas is very flammable, the Hindenburg comes to mind. that is what blew the sides out of this battery. If a battery being charged or discharged, especially at a rapid rate, comes into contact with a spark, that is what happens. even if a wire is dropped across the terminals a battery can explode. I have seen the results of batteries exploding quite a few times. Have a vent to the outside side wall of the compartment that the battery{s} will be contained in, Have that vent as high in the compartment as possible. Also have a vent in the floor so that there will be a cross draft affect. Hydrogen is lighter than air so it will flow out the upper vent. In order for that to affectively work, there also needs to be a vent in the floor, a sort of a cross draft affect.
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cowcharge
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Post by cowcharge on Apr 18, 2017 10:13:30 GMT -8
That doesn't appear to be a sealed battery, so it must have been a Hell of a malfunction to blow it apart like that.
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Post by vikx on Apr 18, 2017 21:29:41 GMT -8
If a battery is defective, anything can happen...
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