Hello,I just bought my first travel trailer a couple of weeks ago and it’s the first camper I’ve ever owned. The trailer is currently wired up to a power inverter that is not currently working. I went ahead and ordered a new 1000 watt power inverter and when I plugged in this power inverter it worked for about a minute then it’s light turned red and the mechanics light that I had plugged into it shut off. If I plug the travel trailer into the house the power inverter works just fine. I’m assuming the deep cycle batteries that are wired in parallel may be the issue but I was wondering how I could test that theory out further. I charged each battery overnight on a trickle charge about a week ago. I touched the leads of the wires with my multimeter and they were at around 11.5 volts and the gauge of wire looks pretty thick to me so I’m assuming that is not the issue. I didn’t know if there was a good way to test out the deep cycle batteries further without buying two new ones. Any help would be much appreciated.Thanks

Here if a nifty chart showing the approximate charge status of a battery verses DC VOLTS...There is a science to charging deep cycle 12VDC batteries..."This is what PROGRESSIVE Dynamics states in their operating manual on how long it takes to charge a battery using the DC VOLTAGEs listed below: "Progressive Dynamics ran this test on the amount of time it took a PD9155 (55-amp) converter/charger set to three different output voltages to recharge a 125 AH (Amp Hour) battery after it was fully discharged to 10.5-volts. 14.4-VOLTS (Boost Mode) – Returned the battery to 90% of full charge in approximately 3-hours. The battery reached full charge in approximately 11 hours. 13.6-VOLTS (Normal Mode) – Required 40-hours to return the battery to 90% of full charge and 78-hours to reach full charge. 13.2-VOLTS (Storage Mode) – Required 60-hours to return the battery to 90% of full charge and 100-hours to reach full charge." This is based on having 17-20AMPS DC current available for each battery in your battery bank... NOTE That Progressive Dynamics doesn't even list using DC Charge Voltages around the 12.0VC range as this would take alot more than 100 hours to achieve a 90% or 100% charge state."Each battery in your battery bank will want to demand 17-20AMPS DC current when you first hit them with 14.4VDC Charge voltage...A trickle charge charrge is only good for topping off batteries...Also your 1000WATT POWER INVERTER wants to demand around 85AMPS DC CURRENT if fully loaded. That a pretty good amount of current to pull from a battery... They will only hold up for maybe 5 minutes at most. The POWER INVERTERs also will want to have very large DC CABLES connected to the battery terminals to perform properlyMore to this battery thing that meets the eye haha...Roy Ken

Inverter or converter ? Most inverters will turn to RED when it is a problem in batteries either volts or amps . Being that the load was only a mechanics lite ???

wanderingbob wrote:Inverter or converter ? Most inverters will turn to RED when it is a problem in batteries either volts or amps . Being that the load was only a mechanics lite ???Maybe this was a halogen work light? Those range from 200W on up...possibly way up, especially for double-headed ones.

You have a couple of things you need to do. First, if the batteries are really low, trickle charging overnight won't charge them. At a trickle charge rate, it would probably take 3-5 days. Second, a reading of 11.5 volts is basically a dead battery. I would pull them out, put a FULL charge on them and then have them tested by a local auto parts store or stop by Harbor Freight and buy one of their battery load testers for $25.00. They work pretty good for occasional use.REMEMBER.....You can't test dead batteries. They have to be fully charged before testing.

GOOGLE 12volt side of life. READ and LEARN

Power Inverter Issues | Good Sam Community

19 Replies

bsmith95610
Explorer
Jun 06, 2016
wanderingbob wrote:
Am I the only one confused ? Must we assume it is an inverter ? I am not sure what the battery disconnect has to do with it , leave it in the on position and maybe battery will charge !

It is a power inverter. I don't know how it works exactly but I know when I plug the RV into the house for power if I take my multi-meter and touch the battery leads with the disconnect turned off the battery is at 10.5-11 volts. If I then switch the battery disconnect on then do the same measurement with the multi-meter it's closer to 13 volts. I'm assuming this is occurring because when I flip that switch the power converter is then sending power over to my battery since that switch is opened up. Maybe I'm not understanding this correctly but that is what I'm assuming is occurring. So everything works correctly when I'm plugged into the house when I unplug the power inverter does not work. I've had my battery on the charger for three days now after two more days I'll unplug it from the charger and test again. I'm assuming my two batteries are dead which is why it won't work when I'm plugged into the house.
westend
Explorer
Jun 04, 2016
Your inverter is red lighting because the voltage is too low for it to operate. 11.5 VDC is a typical low voltage threshold for small inverters. The reason it operates when you have the shore power connected is because the converter is supplying the 12 -> 13 V necessary for correct operation.

I would guess that your batteries may be shot. The warranty date tag on the battery shows 2006 as year of purchase. That puts them past the typical age of most usable trailer batteries. As was mentioned, charge them fully and bring them to an auto parts house for free testing.

I'd like to make a couple of suggestions: When replacing the batteries, choose two 6V GC2 batteries. They have the same footprint as a group 24 battery. The 6 V's are more durable and tolerant of usual RV use and will triple the available capacity. Two 6 V's are able to operate a 1000W inverter.

If you don't have a disconnect switch installed that can interrupt power from the batteries to the trailer, install one for storage times. This is one thing that TT Mfg's don't install and should be in every RV, IMO. If you don't have one and leave the batteries connected, the parasitic draws from alarms, circuit boards, and stereo units will drain the batteries in a week or so.

Make sure you have a fuse or circuit breaker between the inverter and it's battery connection. Use large cable to connect it to the battery and locate it as close as possible to the batteries.

Hoping you get it all ironed out. Inverting battery power allows for more variability of how an owner can camp in the RV and also allows for greater comfort.

Ask about solar power in the "Tech Issues" section of the Forum. Solar is to battery charging like peanut butter is to jelly.:B
Veebyes
Explorer II
Jun 04, 2016
Inverters need a minimum voltage to work. If the battery is shot, the inverter will not work.

Doing some studying on power systems would go a long way to understanding what is going on. As suggested get the book on the 12V side of life.

People are forever confusing inverters with converters & which does what.
tenbear
Explorer
Jun 04, 2016
Looking at the photos, it appears that the batteries are Marine batteries, not true deep cycle. There is a reference to SRM-24 on the battery that indicates that the battery is a group 24 (Interstate web site). Per wa8yxm, a grp 24 deep cycle battery would be good for 75AH.

Seems this battery bank is pretty small to power a 1000 w inverter, especially if they have been only trickle charged for a couple of hours.

The RV should charge the batteries when the RV is plugged in. Check the battery voltage when the RV is plugged in. Depending on your converter the battery voltage should be 13.6v or greater when charging the batteries.
Crazy_Ray
Explorer
Jun 04, 2016
10 to 1 the OP is out of the race.
2oldman
Explorer II
Jun 02, 2016
wanderingbob wrote:
Am I the only one confused ?!
No. We're working on it. Need OP input but it takes awhile.
wanderingbob
Explorer II
Jun 02, 2016
Am I the only one confused ? Must we assume it is an inverter ? I am not sure what the battery disconnect has to do with it , leave it in the on position and maybe battery will charge !
2oldman
Explorer II
Jun 02, 2016
bsmith95610 wrote:
But it doesn't work when I'm not plugged into power which is probably due to the battery not being good.
'Probably' can go away with liberal use of a voltmeter.

By 'work' I guess you mean there's a meter or light of some sort telling you it's working?
bsmith95610
Explorer
Jun 02, 2016
wa8yxm wrote:
How much battery do you have?

Recommended is over 200 amp hours (C/20 rate) for each 1,000 watts of inverter
That means a pair of GC-2 or a 4D per thousand watts.

Group 24 75 AH
Group 27 95
group 29 105
Group 31 130

I'll bet you have a Group 24

I'm not sure what size battery I have. It does not mention any group number or amp hours on the battery. Below are two links to pictures of the battery.

http://www.irv2.com/forums/attachment.php?attachmentid=128864&d=1464796089

http://www.irv2.com/forums/attachment.php?attachmentid=128865&d=1464796089
bsmith95610
Explorer
Jun 02, 2016
bikendan wrote:
sounds like you're talking about the converter, not an inverter.

the converter charges your battery when plugged into shore power or a generator. it converts 120v AC power to 12v DC power.
all RV's have converters but few have inverters.

an inverter allows you to run 120v AC items, from your batteries.

I am talking about a power inverter it was installed after market by the guy who had it before me. When power is plugged into the trailer and I switch the battery disconnect switch so that battery power is turned on the voltage on my battery spikes up to around 12-13 volts which then my power inverter works. But it doesn't work when I'm not plugged into power which is probably due to the battery not being good.