Battery not charging

markjamestx · 02-09-2020, 04:59 AM

Camping in Florida, Panhandle. Need help on battery not charging. We had a power surge 2 days ago and replace the battery. We drove 280 miles yesterday on Interstate 10 going east. Battery should have been charging at that time. All was good until this morning woke to no 12v. New battery is dated last June. We are using a surge protector, but was not when we had the power surge. My question is is there something having to do with the inverter?

Bullet Premier 31BKPR

CedarCreekWoody · 02-09-2020, 06:14 AM

You need to plug in to 120 volt power for a day and let your converter recharge your battery. The power supplied from the tow vehicle provides only a trickle charge at best.

Lee · 02-09-2020, 06:39 AM

Agree with what Cedar states above.

Plug the unit into 120AC.

Next get a DVM (Digitial Volt Meter) even a cheap one from Harbor freight. If you don't know how to use it,... Youtube is your friend.

Measure the DC voltage across the battery while plugged in. You should see between 13.2 - 14.7 VDC.

If you don't then,... you either have a failed Converter or,... an open circuit between the output of the Converter and the battery. (Fuse)

**JRTJH** · 02-09-2020, 06:43 AM

If you have a voltmeter, disconnect the battery completely, plug the trailer into shore power and measure the voltage output ON THE BATTERY CABLES. It should be 13.4 - 13.8 VDC. If the voltage is 0 VDC, check the reverse polarity fuses on the converter/power center. If it's not 13.4 - 13.8 VDC, your converter is bad.

If the converter output is good, then I'd suspect that your battery is the problem. You say that it was "new in June" but all it takes is one or two times of completely discharging it to destroy the battery's capacity to recharge. Certainly, if the battery voltage was below about 10-11 VDC, the vehicle "trickle charge line" would not be capable of recharging the battery, possibly "not at all" and certainly "not in a 4-6 hour tow"....

If the voltage at the battery cables is good, reconnect the battery, let the converter/charger run all night. Disconnect the cables from the battery, let it sit for about an hour (to stabilize) and check the output voltage. It should be 13.6 VDC. At that point, you need to make a decision. 1. reconnect it and try it on the next camping trip or 2. take it to any auto parts store and have the battery "load tested". That will tell you whether there is a bad cell or other problem with the battery.

If it's been discharged "too much/too many times" it may be damaged beyond repair/recharging. With "flooded cell batteries" it's not a matter of "age" so much as it is a matter of "how it's used/abused" that determines how long it lasts.

My guess is that if your converter/charger output is good (13.4 - 13.8 VDC) then your battery needs to be replaced.

Logan X · 02-09-2020, 07:51 AM

I recently had an issue with my battery charging slowly. The problem was where the negative battery cable was grounded to the frame. That connection had become loose. I cleaned the connection and tightened it down. Now the battery is charging normally again.

In addition to the suggestions in the above posts, which are correct, I would check all of your battery connections to make sure they are clean and tight.

markjamestx · 02-09-2020, 07:53 AM

Thank you for all the responses. What's we get hooked up tonight? We will be there for five days and I'll get back and let everyone know how it works. The battery has been charged over the course of two days and I do have a voltmeter a good one and I have a very good charger

GHen · 02-09-2020, 08:02 AM

Great advice from everyone above! Read it carefully.

Just to be clear, it’s called a 12volt battery, but if it’s below 12.2 consider it dead, don’t use it, either charge it up or you will begin to damage it.

**flybouy** · 02-09-2020, 08:23 AM

I would be very "suspect" of buying a 6 or 7 month old battery. Was most likely DOA when you put it in. I would check the acid level in the cells. Most "maintenance free" batteries have access to the cells either under a large plastic cap the covers all or 1/2 of the cells or under a label that you have to peel back to Expose the plugs. Only use distilled water to fill.

A VOM will tell you the current voltage. The 2 true methods of checking a lead acid filled battery is with a "load tester" or a hydrometer. For under $20 you can put a hydrometer in your toolbox.

markjamestx · 02-11-2020, 05:07 AM

Update: converter was bad. New one installed yesterday. An RV tech was actually in the campground here in Eastpoint, FL. Easy install, 4 wires.

Thanks for the help

CedarCreekWoody · 02-11-2020, 05:35 AM

Glad to hear you were able to locate and fix the problem. Thanks for updating us.

MarkEHansen · 02-11-2020, 10:33 AM

Now... as for what killed the converter. A surge protector will not be good enough (even if you were using it at the time). You really should never plug in to shore power unless you are protected by an EMS. Progressive makes very good units. I've installed the EMS-HW30C which is hard-wired inside my trailer. They also make portable units which just plug into the pedestal ahead of your trailer power cord.

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