Should I replace the battery?

[Oberneldon]

Try a watt meter on the output of the inverter and them plug in the device to be tested and see what it is drawing. This Otis how I tell my power usage.

 

[akrvbob]

It's what Sternwake said, the big draw all at once brought the voltage down real fast. The power wasn't gone,it just dropped the voltage, that's why it rebounded.

Your taking too much high amp draw on too small a battery. One possible solution is bigger gauge wires. You may be loosing voltage to resistance. Do you have the battery grounded to the frame or back to the starting battery? That might help also.
Bob

 

[concretebox]

Thanks guys,

I've uploaded pictures of the inverter (A Cobra 1000w/2000w peak) inverter. It's this one. Should I replace it with a more expensive pure sine wave inverter?

I've also uploaded a photo to show the size of the cables I've run from the battery. Big thick wires, not sure what gauge, 4 maybe? The negative is grounded to the frame, so that might be an issue according to some of you. The positive lead is about 5-6 feet from battery to inverter. It's mounted on the dash on the passenger side. The battery is on the driver's side. That's as close I could get it without mounting it under the driver's seat. I could do that and save a few feet, but is it worth it?

 

[SternWake]

A true RMS digital multi meter is needed to get accurate voltage read ings from a msw inverter.

 

[highdesertranger]

a clamp on amp meter around the dc pos or neg will tell you the draw. it sounds like you are drawing to much juice. highdesertranger

 

[akrvbob]

I'm inclined to think too much power draw from too small a battery.
Bob

 

[concretebox]

I'm afraid Bob may be right, but I'm going to try a new inverter and mount it even closer to the battery anyway. I should be using a Pure Sine Wave inverter for my electronics. I'm lucky I haven't damaged the XBOX or TV; maybe because they both have power supplies? I've ordered a 600w Xantrax inverter. It should arrive in about a week.

In the mean time, my battery hydrometer came in and I've got some readings for you all. These readings were taken after the convertor and solar chargers had been charging the battery without the battery in use for 8 hours. I turned both chargers off and waited about 30 minutes. The VoltMinder reported 12.67 volts. The hydrometer had a built-in thermometer, it didn't give specific temperature, but it was well below 80 degrees. The air temperature is 48 degrees. The thermometer did indicate how much to subtract from the hydrometer readings. In this case -18 points. If I understand correctly, then I would subtract 0.018 from the hydrometer reading. The temp-corrected readings are as follows:

Cell 1: 1.257
Cell 2: 1.257
Cell 3: 1.262
Cell 4: 1.252
Cell 5: 1.252
Cell 6: 1.257

After this test I connected the smart-charger, which indicated the battery was at 90% capacity. This would seem to track with the table on this page.

What does this information tell you all?

 

[concretebox]

The TV is 18volt.

 

[LeeRevell]

CB, got my car charger for the laptop - converts 12VDC to 19VDC for the 'puter. They come with different watt/amp ranges. Mine is 3.5amp, there is a similar unit with 5.5amps. Shouldn't be hard to find a conversion tip to fit the TV (assuming it has a DC connector for a wall wart).
Check on Amazon. You'd need to know the amps of the TV.

 

[SternWake]

I bought a dc to dc Boost converter for 5 bucks from amazon that is about the footprint of a debit card an inch high and capable of handling 150 watts .

I dont have a link at this time.

Ive not employed it except to play. LIke feeding a 12 volt fan 28 volts. Some will levitate. .

The op needs to use less x box , or get more battery and solar or utilize more other charging sources.

Bypassing the inverter with can extend battery by 20%. But give or take 15% depending on he specifics of converter or inverter or ac dc or dc to dc power supply.

On the specific gravity one hopes to get at least 1.275 and batteries sold /made for northern cold climates can go to 1.310.

It is important when a battery is new, to fully charge it. And then record a baseline specific gravity so you have a goal to shoot for.

abused batteries usually need a long equalization overcharge to get SG back to or close to baseline. An eq. Charge can be applied to establish a new baseline. Up to 16 volts if monitored closely. Terminate eq charge when SG stops rising or battery approaches 120 f. Disconnect battery from everything but charging source at 15.3v or above. Good luck finding a charging source that can do 16v. That dc To dc boost converter can come in handy after other chargers give up at 14.4v and the battery is craving 16v for an hour or 2. It should not require much more than 5 amps to bring a 100A h battery to 16v after, Only after a 14.x charger has declared good enough all too early, as most do.

achieving a true full charge has little to do with when any given charging source first indicates a full charge. Sounds ridiculous but its true.

regular chargers can eventually get the job done at float afterward, if you have a couple days. Load the battery kinda hard until voltage falls below 12.8, and restart charger. Doing this multiple times can help get the battery which craves 16v and is onlyy getting 14.4 back to near baseline specific gravity. Quit if battery gets above 110f

the closer you can get the battery to 98+% every single cycle the better it will perform and the longer it will last. True 100% is difficult to achieve and might require extreme voltages like 16 v. Which cannot be done more than once every 14 cycles.

the deeper a battery is discharged the more important it is to achieve full charge. And heavy cabling from alternator to isolator to house battery can really make a huge difference in getting a battery from 50 to 80% quickly. Do not fear allow ing he battery to suck up everything the alternator can make. Though the alternator might protest. If it overheats.

 

[concretebox]

xbox converter

http://www.ebay.com/itm/New-AC-Adap...ideo_Game_Cables_Adapters&hash=item5d3b474bc1

This should work with your tv.

http://www.ebay.com/itm/HP-Computer...=Laptop_Adapters_Chargers&hash=item1c4890878b

they both together should be cheaper than a inverter.

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I believe this is the one I used for my Vizio.

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I appreciate the help, but that XBOX power supply is AC-to-DC, like all of them. Believe me, I've been looking for a dc-to-dc power supply for the xbox for a while. I found one DIY solution, but it didn't include any power regulation. I'm not ready to risk my xbox on unregulated power just yet.

The computer car-charger is intriguing, but I'm worried about it too. It says output is 19.5volts. The TV says 18volts. That 1.5 extra volts makes me nervous that it could fry the TV.

I hope that doesn't sound ungrateful, if you can find something I'd love to see a link too it! I just haven't had any luck finding a 12volt solution for the xbox. Powering the TV on 12volt is a possibility, I just want to find one that outputs 18volts exactly.

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So, a frustrating piece of new information: Last night after cooking the battery on the smart charger for a few hours (and it indicating it was full), I got a low voltage warning after just a few minutes...running only the propane furnace and two 12-volt lights! The inverter was off!

I'll have to repeat the test to be sure, but this is quite infuriating. What could be causing this? Is the fuse box too far from the battery? It's about 20 feet away. Is the battery just not fully charged like Sternwake said? It's brand-new, manufactured in October according to the sticker on it. I can return it for a refund. I could try Sternwake's suggestion of cooking it at 16volts and if it fries the battery just return it.

Sternwake, before I try your suggestion, I want to clarify. You're suggesting charging it 16volts, whilst having the caps off the battery to check the fluid SG. Isn't that...extremely dangerous? As far was boiling acid and such? I'm no stranger to danger, I just want to know what I'm getting into. I have the safety glasses, gloves, etc.

 

[Optimistic Paranoid]

Sternwake, before I try your suggestion, I want to clarify. You're suggesting charging it 16volts, whilst having the caps off the battery to check the fluid SG. Isn't that...extremely dangerous? As far was boiling acid and such? I'm no stranger to danger, I just want to know what I'm getting into. I have the safety glasses, gloves, etc.

Here are some explicit instructions from Trojan on doing this on their batteries.

Battery Maintenance

A google search on battery equalization would doubtless find other sites, and possibly some Youtube videos on this process.

Regards
John

 

[SternWake]

Smart chargers usually Stop in the 92 to 95% range.

Bubbling a battery is not boiling a battery.

Where is your low-voltage alarm wired? It should go right to battery terminal s and not share wiring with other loads.

 

[Oberneldon]

SternWake that is right - must check voltage at battery - loads drop voltage

 

[concretebox]

The low voltage alarm has its own dedicated wiring to the battery terminals.

Where does one find a battery charger that puts out 16 volts?

 

[SternWake]

I reprogram my solar controller to do 16v and I initially need 6.2 amps the get my single group 31 to 16v but this is increasing as the battery nears 300 cycles.

I use an adjustable voltage switching power supply as a manual battery charger.
Meanwell RSP -15-500. It will do 13.12 to 19.23 volts and upto 41 amps.
I have a thread on it called my newest electrical toy.

 

[concretebox]

Stern,

I just read your thread on the MW. Impressive. I'll add it to my wish list. Also on that list is a programmable solar controller. Now I just need money coming in.

 

[flailer]

Shouldn't this work for your 18Vdc ? Making everyone happy, for low -v low bucks?
http://uk.farnell.com/texas-instruments/ucc28051d/ic-pfc-controller-18v-8-soic/dp/1619230

 

[concretebox]

My Xantrex PROwatt SW 600 came in today. I hooked it up with jumper cables and tested it running the XBOX and TV. It performed much better than the Cobra. I was able to watch streaming video through the XBOX for about an hour before the low-voltage alarm went off.

This is a significant improvement, but still nowhere near the time I was expecting to get. Even using Peukert's Equation I was expecting about 4.5 hours before reaching 50%, and 9 hours to completely drain the battery. Of course, Walmart isn't forth-coming with the essential information needed for Peukert's Equation, so I had to guess. Even so, it's hard to imagine what variables would result in 1 hour of Reserve Capacity.

One more thing I'll add to this diary: Yesterday I ran the smart charger for several hours until it indicated full (I know it's not the ideal charging solution, but it's what I can afford at the moment). That evening, with the battery "fully charged," the only load I ran on the battery was the propane furnace and propane detector/alarm. It lasted 4 hours, 37 minutes before the low-voltage alarm woke me up. Considering these are 12volt devices, and low-power ones (I assume) this is more evidence that the battery is not performing up to specs.

 

[Seraphim]

http://www.batterystuff.com/kb/tools/peukert-s-law-a-nerds-attempt-to-explain-battery-capacity.html

Suggests that your 4 hour and 37 minute range might be the norm for your battery...

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Not familiar with low voltage alarms. Are u sure the alarm is set up properly. I think I mentioned before I use a battery monitor which provides a reading on remaining power in percentage of amps remaining.

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It also provides readings on current draw, so you know exactly what's leaving or entering the battery

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No guessing.