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Topic: Dry camping battery storage (Read 700 times) previous topic - next topic

Dry camping battery storage

Ok. I have 4 wet batteries, 6v, 100 watt solar and was wondering if anyone has an idea of how often to run the generator for lights and radio and maybe a few hours of dvd per day. I'm thinking I'm good for a week if it's sunny. I'll run the genny for any microwave or air-conditioning needs. My gauge will help but just wondering
1996 U295-36, Cummins 300hp, 8.3. Build number 4864. Vin number 1F97D536XTNO54271. Purchased October 31, 2019.

Re: Dry camping battery storage

Reply #1 –
200 to 300 watts minimum for summertime, your 100 watts would be useful for maintaining battery voltage from parasitic loads only.
Doug W.
96 36' U270 CSGI #4946
04 Toyota Tacoma 4x4
PNW

Re: Dry camping battery storage

Reply #2 –
Short of installing a recording wattmeter and calibrating it every few months the only cheap way is to install a voltmeter reading in 0.1 or to say tenths of the volt.  Check the battery voltage first thing in the morning before you add any load and before the sun hits your solar panels.  12.0V resting is about 50% state of charge and time to start the generator.
1992 Foretravel Grand Villa
U225 SBID Build No. 4134
1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
1962 Studebaker Lark
1986 Honda VF700C
1983 Honda VF750C
Charlie, the Dog was broken out of jail 24 Oct 2023
N1RPN
AA1OH (H)e who must be obeyed.

Re: Dry camping battery storage

Reply #3 –
I tried getting by at BLM land with 100 watts in late July with full sun two years ago. No go, had to run the generator each day at least an hour. I have 480 amp hours of wet cell, so only about 200 - 220 amp hours capacity.
1998 36 foot U270 Build No. 5328 WTFE, 900 watts solar, Victron controller, B2B, bat monitor, 600 AMPH lithium with 2018 Chevy Colorado toad, SKP #110239, Motorcade #17781, retired and full-timer since Dec. 2020. Part of RV family since 1963.

Re: Dry camping battery storage

Reply #4 –
I would consider 100 watts solar as almost no solar. Not much to count on. Using a simple calculation 100w /13v =7.7amps only when sun is shining and only if overhead, something that does not happen.

Keep in mind that solar watt ratings are never reached because laboratory ratings are not real life and solar panels only reach maximum when they are cold. Warm panels have reduced efficiency.

4 x 6v batteries = 2 x 12v batteries. And if each 6v battery weighs less than 75lbs you have less battery capacity then the average Foretravel with just 2 x 8D batteries..

Go play and don't be afraid to experiment with usage and gen run times. More solar is not always the best answer. Generators like to be run.

Re: Dry camping battery storage

Reply #5 –
 I've always been told generators need to be used. This one has 1700 hours and runs great! 8D batteries are much to heavy and pricey for me. I'll stick with the Lifeline/lifetime AGM 4d batteries because of weight and cost. I actually had 2 Trojans separate at the seams after 4 years but they worked great. I may go to the extra tall next time. I'm just trying to get away from wet cell maintenance and damage.
Thanks for the info.
1996 U295-36, Cummins 300hp, 8.3. Build number 4864. Vin number 1F97D536XTNO54271. Purchased October 31, 2019.

Re: Dry camping battery storage

Reply #6 –
Quote from: dans96u295ft –
I've always been told generators need to be used. This one has 1700 hours and runs great! 8D batteries are much to heavy and pricey for me. I'll stick with the Lifeline/lifetime AGM 4d batteries because of weight and cost. I actually had 2 Trojans separate at the seams after 4 years but they worked great. I may go to the extra tall next time. I'm just trying to get away from wet cell maintenance and damage.
Thanks for the info.
In our previous rig, once I realized that the intended use and our actual use were widely separated, and after I did the reading and did the math, we ended up with 4- GC-2 deeper cycle batteries and the 2 BCI Group 27 batteries originally designed in.  We found that in the summer time, when staying in state parks where we really didn't want to run the generator, we could go 3 days maximum without needing a genny run.  Our battery state monitoring equipment was a 12v led voltmeter and a 100A shunt feeding a milli-ammeter.  And a list of resting battery voltages versus state of charge taped to the fridge.

We have found over the past 9 years that with a modern charger and charge controller we only need to water our batteries twice a year and I prefer the 4-D, 8-D batteries because of the fewer connections necessary.
1992 Foretravel Grand Villa
U225 SBID Build No. 4134
1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
1962 Studebaker Lark
1986 Honda VF700C
1983 Honda VF750C
Charlie, the Dog was broken out of jail 24 Oct 2023
N1RPN
AA1OH (H)e who must be obeyed.

Re: Dry camping battery storage

Reply #7 –
WOW! Never heard of only needing water twice a year. That's good. Seems to be a multitude of how high you fill the batteries with distilled water. What is your opinions. My Trojan dealer only wants the plates covered, no more. He said to high is trouble. I don't know what is correct
1996 U295-36, Cummins 300hp, 8.3. Build number 4864. Vin number 1F97D536XTNO54271. Purchased October 31, 2019.

Re: Dry camping battery storage

Reply #8 –
Every apparatus had a service day once a week. We kept the plates covered plus enough to get a hydrometer reading. The reserve trucks didn't get much driving time so would usually require the charger be plugged in. At the inside mild temperatures, they only occasionally required water. If you do use the batteries a lot dry camping, keeping the water just above the plates is a must as a high electrolyte level means some will come out the top when charging and corrode anything close to them.

Water has a unique property in that it expands at low (freezing) temperatures and also at high temperatures. No conventional battery should ever be charged above 125 degrees (battery temp) or it will be damaged and the liquid expansion will force the electrolyte out the vents.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Dry camping battery storage

Reply #9 –
Quote from: dans96u295ft –
WOW! Never heard of only needing water twice a year. That's good. Seems to be a multitude of how high you fill the batteries with distilled water. What is your opinions. My Trojan dealer only wants the plates covered, no more. He said to high is trouble. I don't know what is correct
Adding to what Pierce said, just cover the plates if the battery is in a low state of charge.  The level will rise as the battery becomes charged.*  That being said I fill my fully charged batteries to the full mark.  For me that's usually the ring at the bottom of the well, or the full line on the side of the motorcycle batteries.  Motorcycle batteries for what it's worth receive the roughest treatment you can imagine with crude charging systems, heat and vibration.

*There's more mechanical movement inside a lead acid battery between full and discharge than you might be aware.
1992 Foretravel Grand Villa
U225 SBID Build No. 4134
1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
1962 Studebaker Lark
1986 Honda VF700C
1983 Honda VF750C
Charlie, the Dog was broken out of jail 24 Oct 2023
N1RPN
AA1OH (H)e who must be obeyed.

Re: Dry camping battery storage

Reply #10 –
Excellent. I'll keep them above the plates only. Yes, motorcycle-lawn mower batteries are tough. The gel's have fixed my isuues in the motorcycles along with the no need to add water. Love them
Thanks folks
1996 U295-36, Cummins 300hp, 8.3. Build number 4864. Vin number 1F97D536XTNO54271. Purchased October 31, 2019.