Battery Life

[rockcandymounta]

I posted this question on another RV forum and Ill be darned if I can find that forum. (arrgh). So much for keeping good notes.

Anyway, I have a 2016 Dutchman Denali 38ft 5th Wheel.

I'm thinking the batteries need replacing because when I am on battery power and attempt to use the auto leveling feature, I get a low voltage error.

However before I buy 2 new batteries, Id like to be able to test and see if the rig is charging the batteries when plugged into shore power.

I have one of the Harbor Freight cheap multimeter but know nothing about how to use it to check volts, etc. Any help would be appreciate.

Thanks

[Grit_dog]

From what I read, I don’t understand your claims aside from a lower useable DoD, about 30% vs 50 % compared to lead acid. And slightly more overall capacity.
And of course life cycles.
But you’re twisting the numbers/descriptions like most adverts for SIO2 batteries.
You’re basically claiming 4x as much useable power comparatively, or actually 2x as much because you’re comparing 6v to 12v.
But the difference is on the order of about 20% better with many more lifecycles. From what I can observe.

And the OP hasn’t even come back, which is good since this thread de railed upon your suggestion.

[pianotuna]

philh wrote:

But wouldn't a pair of 12V batteries do better cooking a costco size box of hot pockets?

Flooded batteries are "rated" at a 25 amp draw @ 25 C (77 f)

So 4 pairs would give a continuous output of 100 amps, with 450 amp-hours of reserve (8 jars)

That may run a microwave for a time, and many folks have done so, when the wire is big enough and the bank is close enough to the inverter.

8 pairs would be 200 amps, with 900 amp-hours of reserve. (16 jars)

That would run the microwave for a long long time.

1 SiO2 can do 342 amps and a pair can do 684 amps, with 200 amp-hours of reserve.

So IF you go by rated capacity, the pair of SiO2, in THEORY ought to be a bit better than 4 pair of golf cart jars, as a single SiO2 can run a microwave at 20% state of charge. I would imagine that with twin SiO2 the microwave would run at 10% state of charge.

It boils down to which is cheaper per amp-hour and how much weight one can carry.

[philh]

Grit dog wrote:

pianotuna wrote:
Grit Dog

Golf cart batteries are great--until you try to run a microwave via a 2000 watt inverter. Then you find out they had better be about 80% full or the inverter may shut down.

And the OP asked about using his leveling jacks.
Idk of alot of people that have $50k 5th wheels and live solely off of an inverter. You can't really "use" a big camper's amenities off of a little inverter.
And the OP doesn't even know how to check a battery, so doubt he's got a mac daddy electrical system hooked up.
Although, with a rig that size, for roughly the cost of 2 SIO2 100ah batteries, he could have a 6 to 8 battery bank of 6V FLA or SLA batteries that would make a whole costco size case of Hot pockets in the microwave, as fast as he could eat them if that was his jam. And still blow dry his hair and make coffee the next morning without even charging up.

But wouldn't a pair of 12V batteries do better cooking a costco size box of hot pockets?

[Grit_dog]

pianotuna wrote:
Grit Dog

Golf cart batteries are great--until you try to run a microwave via a 2000 watt inverter. Then you find out they had better be about 80% full or the inverter may shut down.

And the OP asked about using his leveling jacks.
Idk of alot of people that have $50k 5th wheels and live solely off of an inverter. You can't really "use" a big camper's amenities off of a little inverter.
And the OP doesn't even know how to check a battery, so doubt he's got a mac daddy electrical system hooked up.
Although, with a rig that size, for roughly the cost of 2 SIO2 100ah batteries, he could have a 6 to 8 battery bank of 6V FLA or SLA batteries that would make a whole costco size case of Hot pockets in the microwave, as fast as he could eat them if that was his jam. And still blow dry his hair and make coffee the next morning without even charging up.

[pianotuna]

Grit Dog

Golf cart batteries are great--until you try to run a microwave via a 2000 watt inverter. Then you find out they had better be about 80% full or the inverter may shut down.

[Grit_dog]

pianotuna wrote:
rockcandymountain,

You may wish to consider SiO2 batteries as their discharge rates are pretty astounding. They would cost more.

Or a pair of 6V SLA batteries that will give similar performance for 1/3 the price of Si02s.

And OP, you make it sound like only your self leveling feature is throwing the low voltage alarm. Granted it pulls a lot of amps for a short period of time, but if the batteries were toast or not getting charged, other DC loads would suffer too.
Do you ah e issues with other battery loads?

[Grit_dog]

rockcandymountain wrote:
All of you guys ROCK!! I am gonna wait til I get down to Phx in March before I tackle this but it is already printed out and in my travel notebook and I will let all know how it went!

?? You’re against making repairs before a trip?
Aren’t we just talking about 5minutes to determine if the batteries are getting charged and then possibly a simple battery replacement?

[bikendan]

rockcandymountain wrote:
I posted this question on another RV forum and Ill be darned if I can find that forum. (arrgh). So much for keeping good notes.

All you had to do was to go to your profile and click on "view your posts".
Here's your original thread:

https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/30197682.cfm

[pianotuna]

rockcandymountain,

You may wish to consider SiO2 batteries as their discharge rates are pretty astounding. They would cost more.

[rockcandymounta]

All of you guys ROCK!! I am gonna wait til I get down to Phx in March before I tackle this but it is already printed out and in my travel notebook and I will let all know how it went!

[wanderingaimles]

IF you are going to have to replace the batteries,,,,,
Go to Sams club, Costco, Batteries + or wherever to get 2 six volt golf cart batteries instead of the standard rv/marine batteries, cost wont be but about $20 more, and they will give you twice as much usable power before you start damaging them from over draining, and should last longer.
NOTE you do have to change how they are wired when you install them. Come back here and guidance will be given.

[midnightsadie]

and don,t buy auto batteries, there not for rv.s

[opnspaces]

An even more basic test but I didn't want to edit what was above.

With the shore power plugged in take a voltage reading at the battery (steps 1 and 2 above)

If the reading is higher than 13 volts your batteries are receiving a charge from the shore power cord.

If you have solar on the trailer then disregard and let us know so we can advise further.

[MFL]

Simple way...unplug from shore power, set meter to 200 DC (mine, have not seen the HF cheapie) and check battery. Red probe to pos, and black to neg post. Remember reading (mine, likely 12.8 to 13 volts).

Now plug into shore power, go back, do the same, set meter same, touch probes, if charger is working, should see 13.2 to maybe 14v.

A digital meter is nice, not sure what you have.

Jerry