Fridge Causes Voltage Drop?

Battery load test is a good place to start, and given what we've seen on this thread and elsewhere, there is a good chance that four years of less than ideal charging has killed the batteries.

Better battery life requires really good charging technology and usage habits. Or, go the KISS route and keep the original system, go camping and be happy. You just have to get used to buying batteries every couple of years as a cost of ownership. ;-)
 
Vic, thanks for the reply. You said 'better battery life requires really good charging technology and usage habits'. I do think I use my batteries in a 'good' way, if there is such a thing....but, maybe you're referring to the Zamp controller. I'm going to get a couple new batteries - went to my local auto store and they tested mine...one is about 45% amp capacity and the other 30% - but wondering if I should replace the controller, as some have done on here. Those that have seem to be happier....
 
I have the Victron controller/monitors in mine and love them. Highly recommended.

Good means that you monitor the charge level with something more than what the ZAMP has. Victron BMV or Trimetric TM2030. Something that uses a shunt to measure AH in and out so it can guess at the batteries real State of Charge.

Good means that you don't discharge the batteries too deeply too often. I aim at no more than 50% discharge, ever. Rando advises that this is conservative, and deeper discharges are OK.

Good means you get the spec sheet for your batteries that lists the voltages/currents that your specific batteries need, and set the controller to use those. Good batteries (Lifeline, Trojan, Rolls) will have those kinds of spec readily available to you.

Oh, and 45 and 30%... wow, those batteries are toasted!
 
That's why I'm starting with the Victron BMV 700 monitor so I can get better visibility into what my Zamp controller is really doing and how we're really using our batteries. The Victron controller will be next on my list if the Zamp just isn't cutting it. I'm not interested in replacing batteries every couple of years.
And Vic - thanks for the list. That's very helpful!
 
Vic Harder said:
I have the Victron controller/monitors in mine and love them. Highly recommended.

Good means that you monitor the charge level with something more than what the ZAMP has. Victron BMV or Trimetric TM2030. Something that uses a shunt to measure AH in and out so it can guess at the batteries real State of Charge.

Good means that you don't discharge the batteries too deeply too often. I aim at no more than 50% discharge, ever. Rando advises that this is conservative, and deeper discharges are OK.

Good means you get the spec sheet for your batteries that lists the voltages/currents that your specific batteries need, and set the controller to use those. Good batteries (Lifeline, Trojan, Rolls) will have those kinds of spec readily available to you.

Oh, and 45 and 30%... wow, those batteries are toasted!
Click to expand...
Vic, thanks again for your detailed reply. Unfortunately, there's a new twist to the saga.

I wasn't sure that the first place I went to to test the batteries gave me reliable feedback, so I went to another auto parts place to double-check...their test showed the batteries were FINE. I had them do it over again, and the second round of tests showed they were marginal......WTF???? I left there disgusted and went down the street to an auto repair/wrecking shop. The guy there was VERY helpful. I explained what happened with the previous two visits, and he told me he would 1) put both of them on the charger to make sure they were both fully charged before he tested them, and 2) he would use his $1500 load tester, which AAA uses, to see what was going on. Came back a few hours later and......both batteries are FINE. No need to replace.

Now I don't know what to do. My guess is that my frig is causing the sporadic voltage drop, and drawing so much current that it's dooming the system. When the drops happen, the compressor on the frig keeps cycling on and off. I wonder if there's a voltage regulator on the frig, like on a car, that could cause that. I guess the other option is the solar controller, but I think that's working fine. Today I left the camper out in the sun all afternoon, with the frig running, only on battery power, and the controller read 'FUL' for most if not all afternoon, meaning the batteries were topped off, and the frig ran consistently (I had the thermostat turned all the way up to the coldest setting). Last night when we were camping, about an hour after the sun set, the frig started its on/off thing again, with voltage drops every time. The only things we were running at the time were the frig and one ceiling fan.
 
Consider a battery monitor as Vic suggested to account for what the Zap is doing as far as what it thinks is "full". Need to know what voltage the battery is getting at bulk, absorb and float levels of charging. Or just buy a Victron solar controller where you can totally program it for those Fiama battery's. On the side of them there is voltage for bulk and float and the Victron can match.

If you can afford the cost get both units. Both can be seen on Bluetooth and adjustments on IPad or smart phone.

I went both routes as was suggested here by Rando, Vic and others and have been very happy with the results. I also have 2 Fiama battery's and a Dometic battery refs. Ref will pull around 4 to 5 amps while running.
 
Thank you Patrick. I'm going to give this some more thought, but I think I'll probably end up doing as you suggest. I find it very frustrating that my batteries both check out OK, but once the sun goes down I can't get much use out of them....I'm still suspect that the frig is doing something weird, but I'm not an electrician....there's a guy down the street from me here in Jackson that has worked on RV appliances for years, I may run it by him. Thanks again for your input, it is much appreciated.
 
Battery monitor will tell you amps the refs is using along with everything else electrical. The battery monitor is like a gas gauge for going out and coming back into the battery's. It will show you that you may not be getting all that you can out of solar with the zap controller. The zap maybe not giving you a true bulk and absorb state and length of time required for the 2 ATM Fiama batteries, it takes longer with 2 batteries than one. And maybe the zap controller is not matched for your batteries.

Also with a battery monitor you can see if the refs is doing something weird like using more amps that you think.
 
Thanks for all the input. I'm doing some experimenting. My initial assumption was that the batteries were bad, so I 1) charged them fully from shore power for a few days, 2) pulled the fuse on my solar panel, so they wouldn't charge from the panel, and 3) turned my frig on and disconnected shore power. Wanted to see how long it would take for the frig to fault - typically, when we're dry camping, it faults about an hour or two after the solar panel stops getting enough sunlight to put power into the batteries/system. What happened surprised me - the frig ran all night, no faults, and is still running today. Voltage at the batteries measures 12.6 . So, the frig has been running on battery power for over 18 hours now, and still going strong. This is NOT what happens when I camp. I'm thinking now that the problem must be either the frig, or the Zamp solar controller. I've reactivated the solar panel/controller, and covered the panel so it's not collecting sunlight. Want to see if I can force the frig into a fault mode, like when I camp. If I can, I'll probably replace the solar controller with a different brand. Some people here have recommended Blue Sky, others Victron....not sure which way to go.
 
My takeaway from what you said is that you fully charged batteries from shore power for a few days. That would have given enough time at float charge to get the batteries to 100 percent.

You disconnected all charge power and ran the refg to see how long and at what voltage you would see. You were surprised.

I believe it all points to your solar controller not being able to bring the batteries back up to 100 percent like you did with shore power.

A battery monitor would be quick to see how much the controller is lacking.

I would suggest looking into Victron solar controller the smart version with Bluetooth as I have been pleased.
 
For those of you who have replaced the Zamp controller with the Victron (no display), where did you put that controller? How did you address the wiring if you moved it from the Zamp location? And what did you put in the Zamp controller's place since there would be a big hole there :)?
 
The controller can go near the battery, inside hidden anywhere (as long as it can get some cooling). The empty space I could imagine covering it up, making a shelf cubby hole, or install a pull out draw.
 
The controller needs a bit of air behind it too, as the back/mounting surface is a metal heat sink. I used 1/2" Standoffs made out of alum tubing to give it that space. Manual even says "Do not mount directly to flammable surfaces" 1/2" should be enough.
 
I just installed a Bluesky SB3000 and with a small amount of cabinet trimming (about 1/2 cm on one end) it fit perfectly where my Zamp was. It's a much more sophisticated controller.
 
@pvstoy....thanks for all your input. Without belaboring this any further, after some more thorough testing we found that the batteries were bad....our testing initially wasn't correct. I've replaced the 12V AGMs in parallel with two 6V wet cell batteries in series, rated at 230ah each. They're golf cart batteries. Everything is working fine now, and my IOTA converter is charging everything the way it should when plugged into shore power. Solar panel is working fine as well. The only additional modification I may make is changing out the Zamp controller for another brand with more controls/inputs, as you suggested, and possibly a battery monitor as well. In fact, the battery monitor is a higher priority, so I can see if, in fact, the solar panel is charging the batteries like it should. It's been a frustrating process.
 
dharte said:
I just installed a Bluesky SB3000 and with a small amount of cabinet trimming (about 1/2 cm on one end) it fit perfectly where my Zamp was. It's a much more sophisticated controller.
Click to expand...
Do you have Zamp solar panels? Also, what kind of battery setup do you have?
 
radarcontact said:
Do you have Zamp solar panels? Also, what kind of battery setup do you have?
Click to expand...
I have the Zamp 160w panel installed by FWC, and I upgraded to a dual 6v battery set-up when I installed a 2-way fridge a few months ago.
 
I have my camper stored and covered and plugged into shore power. I have a dehumidifier running and the fridge running while covered. I do have solar and was wandering if I need to do anything to the battery in this situation.
 
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