1 or 2 new batteries? |
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GlueGuy
Senior Member Joined: 15 May 2017 Location: N. California Online Status: Offline Posts: 2630 |
Topic: 1 or 2 new batteries? Posted: 30 May 2017 at 2:20pm |
Good quality batteries usually have very specific set points, regardless of them being wet, dry, or whatever. Even wet batteries from different manufacturers will have slightly different set points. So unless your charge controller is programmable, you will probably never be exactly on the specifications for a particular manufacturer. There will be specific, and generic set points. A non-programmable charge controller will be set to some generis set points that will be "safe", even though it may not be "exact". |
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bp
2017 R-Pod 179 Hood River 2015 Ford F150 SuperCrew 4WD 3.5L Ecoboost |
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SDTrialer
Newbie Joined: 01 Apr 2017 Online Status: Offline Posts: 29 |
Posted: 30 May 2017 at 5:25pm |
I have 2 12v batteries. With a full charge, I can run the heat at night with the thermostat set at 60, run the refrigerator on propane, shower each day, use the stove, and use the lights when needed for 4 days/3 nights before needing to charge the batteries.
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GlueGuy
Senior Member Joined: 15 May 2017 Location: N. California Online Status: Offline Posts: 2630 |
Posted: 30 May 2017 at 5:53pm |
Two batteries the same size & weight should have the same amount of energy (measured in watt-hours) regardless of voltage.
Many of the 12V batteries available don't have a huge amount of energy. Most of the 12V batteries in the desired size range are around 75-85 amp-hours (20 hour measure), which is only 900-1020 watt-hours. Convert any battery you're looking at to watt-hours in order to get an apples-apples comparison.
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bp
2017 R-Pod 179 Hood River 2015 Ford F150 SuperCrew 4WD 3.5L Ecoboost |
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StephenH
podders Helping podders - pHp Joined: 29 Nov 2015 Location: Wake Forest, NC Online Status: Offline Posts: 6289 |
Posted: 30 May 2017 at 6:07pm |
How do you do the conversion from amp-hours to watt-hours? It looks like you multiply the amp-hours x the voltage. When using 6V batteries wired in series, would one multiply the AH x 6 or x 12?
215 AH (20 hour rate) x 6V = 1290 watt-hours 215 AH (20 hour rate) x 12V = 2580 watt-hours In other topics, I have read that series adds voltage, but amperage remains the same. Parallel adds amperage but voltage remains the same. |
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StephenH
Happy is the man that findeth wisdom,... ouR escaPOD mods Former RPod 179 Current Cherokee Grey Wolf 24 JS |
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GlueGuy
Senior Member Joined: 15 May 2017 Location: N. California Online Status: Offline Posts: 2630 |
Posted: 30 May 2017 at 8:18pm |
So two 215 AH 6 volt batteries is 1290 watt-hours. You have two of them, you've got 2580 watt-hours. A rough equivalent in 12V would be two 110 AH batteries. 12 X 110 = 1320 watt-hours. You strap in two of them, you've got 2640 watt-hours. And it works just as you describe, parallel gets you the same volts, but doubles the current. In series, you double the voltage, but keep the same current. Potato versus potahto. |
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bp
2017 R-Pod 179 Hood River 2015 Ford F150 SuperCrew 4WD 3.5L Ecoboost |
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StephenH
podders Helping podders - pHp Joined: 29 Nov 2015 Location: Wake Forest, NC Online Status: Offline Posts: 6289 |
Posted: 30 May 2017 at 9:59pm |
The difference then would be whether the batteries are true deep-cycle batteries that can be drained down below 50% without affecting their lives.
The ones I see on Batteries + Bulbs is a Duracell SLI24MDC Ultra with 75 (20 hour rate) AH. That would be 900 watt-hours. Two in parallel then would yield 1800 watt-hours. There is also a group 31 battery, SLI21MDC Duracell Ultra with 105 (20 hour rate) AH or 1260 watt-hours. Double that for 2520 watt-hours for the pair. The cost of the group 31 battery is significantly higher than the GC2 batteries I bought. This has been an interesting and informative discussion. I plan to stick with my GC2 batteries until there is a viable alternative. |
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StephenH
Happy is the man that findeth wisdom,... ouR escaPOD mods Former RPod 179 Current Cherokee Grey Wolf 24 JS |
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geewizard
Senior Member Joined: 16 Apr 2017 Location: Spokane Online Status: Offline Posts: 347 |
Posted: 31 May 2017 at 9:38am |
I bought a battery box from http://www.rvlockbox.com/ You can see my post on installing it here: http://www.rpod-owners.com/forum_posts.asp?TID=9728&KW=&title=rpod-177-battery-box-mod |
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2021 Winnebago Micro Minnie 1708FB
2017 R-Pod 177 (Blue) HRE SOLD 2004 Outfitter Apex 8 camper 2014 Toyota Tundra DC |
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GlueGuy
Senior Member Joined: 15 May 2017 Location: N. California Online Status: Offline Posts: 2630 |
Posted: 31 May 2017 at 10:08am |
Our R-179 came with two boxes, and two batteries. Separate tie-down strap for each one.
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bp
2017 R-Pod 179 Hood River 2015 Ford F150 SuperCrew 4WD 3.5L Ecoboost |
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