House battery problem - is it me or Interstate?

[gcvt]

Quick backstory: Bought a 1997 Sportsmobile last August. Class B Ford Econoline E250 extended body van. Two group 27 batteries in parallel, dead house batteries when I bought it. Intellipower 9100 converter/charger.

When I bought the van I picked up two new Interstate ECL Pro 27 deep cycle batteries. They lasted eight months. Don’t know why the went bad, but the date stamp indicated that they were manufactured two years before I bought them. Thought that was the problem. Never dry camped more than three nights in a row on them. Draws are a Norcold fridge (2.3 amp draw), 6 rarely used LED light fixtures, one new unused dual-USB outlet, and the water pump when the faucet is on.

Interstate said they had a high return rate on the “Pro” series batteries and replaced them under warranty with their regular SRM27s. Had those about 12 days unused. They were 12.7-12.8 and I checked them daily. Turned on the fridge for the first time and they went to 12.3v in one hour.

Took them back and they load tested one of them. It was at 12.87v but had 0 cranking amps. This was at our local Interstate batteries warehouse/distributor, not a regular dealer. The tech looked confused. They gave me two more new SRM27s. Went camping this weekend and got the same result. Mostly fridge-only use and they get drawn down very quickly.

When the engine is running, they’re charging at about 13.9v. When plugged in to the Honda EU2000 generator, they’re charging at 13.4v. Verified this using a newly installed dual battery monitor and one of those cigarette lighter battery monitors. My buddy brought his fancy Fluke clamp meter this weekend and we confirmed that the fridge is drawing 2.3 amps, and that there is no draw when everything is shut off.

Before I go back to Interstate, is there anything else I should be looking at here? Seems unlikely that I’d get so many bad batteries from them. I know they’re not the highest quality but 12.8 to 12.3 in an hour is perplexing.

Side note: Ordering a 100w flexible solar setup from Renogy soon - with the 20A charge controller that will allow me to add a second panel later this Summer. But, I gotta get this battery situation figured out first.

[Chris_Bryant]

Regardless of battery issues, those charging voltages are too low, IMHO . I would get a pendant for the PD 9100 so you can get over 14 volts for bulk charging.

[Golden_HVAC]

Chances are that the battery is to blame.

Next time you get replacement battery, ask them to load test the new ones. IF you get 0 cranking amps, or less than 400 cranking amps, you have a defective battery from day 1. My guess is you have one bad battery that brought down the good battery. They should replace both, and test both to make sure they are working good before leaving the place.

I would recommend a normal solar panel. Check out the prices here for solar panels. SunElec.com I was looking over the specs on a 140 watt $229 panel yesterday. It has a aluminum frame, so it can be mounted 1" above the roof, and cool air can circulate under the panel to cool it.

I used 2" angle aluminum to make my panel mounts, with 3 holes 3/16" diameter for #10 screws into the roof, and 5/16" hole for a 1/4-20 bolt into the solar panel frame. Some rubber roof sealant below all the mounts and on top of the screws will secure it all, and prevent leaks. Yes even in a steel roof.

I might install 'nutserts' into the roof of a van I am buying to install a 120 watt solar panel on it. This will charge the engine battery, and make sure that there will be plenty of power for the 65 amp handicap lift that will be installed. I will also install a Fantastic fan, and 1,000 watt MSW inverter that was given to me. That will be plenty to run a TV or anything I plan on using, as well as the 250 watt wheelchair charger.

If you have not heard of nutserts, google it, or look up how to install on youtube. One 1/4-20 nutsert will be plenty of pull out strength for each solar mount when mounted to your steel roof. I put nutsets into my solar panel frames, and used 1/4-20 tamper resistant bolts to prevent them from leaving my roof - none stolen so far in 20+ years.

I might even mount my Fantastic fan with some #10-32 nutserts that I have sitting around. It would work perfect, and offer a raintight seal as well (once covered with rubber roof sealant).

You can buy nutserts at Grainger.com or perhaps your local hardware store?

I plan on drilling a 7/8" hole in my roof (I am talking about my new $45,000 van, not something old that has a few scratches on it already) and using a water tight connection to bring in my wiring from the roof. Then take that to a 20 amp controller, near the battery. And wire the interior lights and fan to a 20 amp fuse. I will probably use 2 each 1/4-20 nutserts for each of the 4 roof brackets in my van, so I am extra secure. . . . I have a whole box of 1/4-20 nutsets, so why not? I bought a box of 50 each tamper resistant bolts from Grainger.com many years ago.

If you have a CO meter, it can draw about 4 amp hours daily, and the propane leak detector and solenoid can draw another 5-8 AH daily if that is left on. The 100 - 120 watt solar panel can make up for all the amperage that the refrigerator 'should' be drawing.

My water pump draws 7 amps per hour, and that seems like a lot, but it also pumps 2 GPM, so can empty a 120 gallon water tank while using just 7 AH. It is a insignificant load. With your 20 gallon tank, that is less than 1 AH to empty that tank, or about 12 watts!

Nutsert install with 2 wrenches. https://www.youtube.com/watch?v=wKPA2CxOo_0

Good luck on your next set of batteries and solar panels.

Fred.

[DAS26miles]

Check out my topic
Interstate batteries not up to ah rating

Lots to read, but mine never got really topped off and were probably only 80-90% plus sulfating added to the problem. Took lots of babysitting on a friends old manual charger to clean up the mess and get the specific gravity up to 1.275.
First I recommend you get a good SG hydrometer and check each cell. Log it, write it down. Check the voltage against the SG. Mine showed that it was charged on volts, but SG showed 75%.
I bought the Renogy 100 watt suitcase and it works great. My controller has an equalization function and I can get my volts up to over 16.

[MrWizard]

what is your fridge and where do you get the 2.3 amp number

2.3 amps at 12.3v = 28.3 watts, 10hrs = 23 ampHrs used
this LP or electric, 28w is low power for electric, a little high for control board and lp valve use

2.3v at 120vac = 283 watts, which is what an electric heating element might use for an RV absorption fridge

NEVER run an RV fridge on battery power, except with engine running
with that kind of power draw you need a very large battery bank

a 2way or 3way fridge in a "B" should be on propane , you can use electric mode
IF you are shore power, and only when on shore power

please provide FULL info from fridge, and what mode you are using