Charging Deep Cycle 12V battery off a cheap generator?

[41magsnub]

At the cabin we have a 20yo Coleman Powermate 5000 generator that kicks butt on power tools (what it is really for), but the power is not clean enough for anything remotely sensitive.  When it is not under load, the engine "surges".  I've tried my el-cheapo auto parts store battery charger up there, no worky.  It wasn't enough load to get the generator to settle down.

I'll be spending 9 days up there in a stretch in August and will need to recharge a deep cycle battery a time or two for a CPAP machine.

I'm looking at this:  IOTA DLS-45/IQ4  http://www.iotaengineering.com/dls45.htm

Supposedly this unit will handle crappy power.  Any thoughts on that?  Am I asking for the impossible with this rough of a generator?

[Brad Johnson]

How much additional load does the generator need to get it to settle?  Would it be easier/cheaper to up the load by plugging in something high-draw that you could leave on while the unit charges?  I'm thinking soldering oldering iron or somesuch.

Brad

[Nick1911]

Could you perhaps provide some other load to help stabilize the governor?  Perhaps space heater set on low?

In lieu of that, I'd consider a ferroresonant power conditioner, but that's expensive and heavy.

Many modern switched mode power supplies supposedly operate just fine on crap power - they immediately rectify and smooth it to high voltage DC anyway - so frequency and variations of voltage don't matter that much.  That said, I don't have much experience with it personally.

[41magsnub]

Any power tool settles it right down.  I'm mentally inventorying my power tools and there is nothing I would want to just let run for several hours.  I suppose I could get a harbor freight drill and tape the trigger.  That might be a ~$8 solution.

[charby]

Any power tool settles it right down.  I'm mentally inventorying my power tools and there is nothing I would want to just let run for several hours.  I suppose I could get a harbor freight drill and tape the trigger.  That might be a ~$8 solution.

A cheap box fan?

[RevDisk]

I plan on filtering my generator output through a UPS. That will filter, but not load the generator.

For load, go with a radiant heat oil filled space heater. Unlikely to catch anything on fire.

[41magsnub]

Forgot - many years ago on this generator we tried a little APC Smart UPS something or other with the idea of recharging a laptop battery.  Even after setting the voltage sensitivity to the widest range the UPS kept going into shutdown.

[RevDisk]

Yea, that'd be the problem. You'd need an on-line UPS. Double conversion is the preferrable term for googling. Line interactive or standby UPS won't work correctly. They're not cheap. Think $500 plus.

Might be cheaper to buy a smaller, cleaner inverter generator for the sensitive stuff, and keep the larger generator for stuff that handles clunky electricity.

I'm eyeing up something like this: http://www.amazon.com/Hyundai-HY2000si-2200-Watt-Portable-Generator/dp/B004919NEK

[roo_ster]

deep cycle battery a time or two for a CPAP machine.

How does that work for you? 

[41magsnub]

How does that work for you? 

Quite well.  I used to use an inverter which was annoying and inefficient, but functional.  Then I looked up the specs on the power supply for the CPAP.  It is 12V and designed to feed right off a battery.  Bought the right cable and it is much happier, no annoying inverter fan.

[roo_ster]

Quite well.  I used to use an inverter which was annoying and inefficient, but functional.  Then I looked up the specs on the power supply for the CPAP.  It is 12V and designed to feed right off a battery.  Bought the right cable and it is much happier, no annoying inverter fan.

Mine requires 24V, so I am gonna have an inverter of some sort.

[Brad Johnson]

Mine requires 24V, so I am gonna have an inverter of some sort.

Two batteries in series.

Which brings up another possibility for the OP.  Would it be feasible to chargd the battery off your vehicle by using jumper cables? Not elegant, and certainly not as economical to run as a dedicated generator. But you also don't have to buy anything except a little extra fuel for the car.

Brad

[Balog]

Nothing beats electric resistance coils for adding false load. When they do a load bank test on big generators for buildings the truck is basically just a gigantic toaster parked on the street.

But buying a smaller gen set is the right answer. Saves gas in an actual emergency.

[41magsnub]

Which brings up another possibility for the OP.  Would it be feasible to chargd the battery off your vehicle by using jumper cables? Not elegant, and certainly not as economical to run as a dedicated generator. But you also don't have to buy anything except a little extra fuel for the car.

Brad

That is my backup plan, I thought that was pretty tough on the batteries and alternator though (mostly if I screw up and run the battery down too low).

[Jim147]

I have one of the little $80-90 Harbor Freight 2 cycle generators here that will run a charger for close to eight hours on a gallon of gas. That would take care of that part. I haven't tried it with the computer or TV to see if it plays well with other electronics. I charge the batteries and run the other stuff off inverters.

I had to run it for about three hours Saturday morning after a storm came through here. I just needed some light to see my metal brake but had to run my large shop fan to keep it running smooth.

jim

[never_retreat]

A ups won't solve the problem. Mine best power ware unit hates the generator. Most ups monitor HZ also and I believe thats what keeps mine in battery mode because the power is stable.
I second the dummy load to settle down the generator.
Or try and find an old style just a transformer type dumb charger.
Or cheapest option would be to charge the batteries with whatever you drove to the camp with jumper cables.
Unless you driving something with a big v8 in it most cars at idle will burn less gas then a generator like that.

[2nd_to_one]

When I'm running my generator (7500W) for maintenance purposes I just plug in one of my 500W halogen lights to provide a load.  This should be more than sufficient to stabilize the generator for your purposes and you probably have one already.

Steve

[bedlamite]

Have you considered something like a solar charger?

http://www.amazon.com/Instapark-PowerBox-Fold-n-Go-Solar-powered-Controller/dp/B007VWW8X2/ref=sr_1_1?s=automotive&ie=UTF8&qid=1402431590&sr=1-1

[RevDisk]

Have you considered something like a solar charger?

http://www.amazon.com/Instapark-PowerBox-Fold-n-Go-Solar-powered-Controller/dp/B007VWW8X2/ref=sr_1_1?s=automotive&ie=UTF8&qid=1402431590&sr=1-1

Just saying, you could get a regular (smaller) generator for that price or an inverter for not that much more.

Generators use fuel, but they work at any time and under nearly any environment condition.

I have panels that big or bigger. The number you are given is peak. That is the max under a perfect sky at the perfect angle under perfect conditions. The reality is about half of the advertised number. So, for $300, you'd get maybe 300-600Wh per day. Now, this might be perfect for low voltage applications. Temperature or environmental sensors, charging a cell phone, remote signs or lights, etc.

[bedlamite]

Just saying, you could get a regular (smaller) generator for that price or an inverter for not that much more.

Generators use fuel, but they work at any time and under nearly any environment condition.

I have panels that big or bigger. The number you are given is peak. That is the max under a perfect sky at the perfect angle under perfect conditions. The reality is about half of the advertised number. So, for $300, you'd get maybe 300-600Wh per day. Now, this might be perfect for low voltage applications. Temperature or environmental sensors, charging a cell phone, remote signs or lights, etc.

I'm well aware of that. A cell phone with a 2000mAh battery holds about 8Wh at a 50% charge efficiency and the low end of your estimate you could still fully charge 20 of them, which is irrelevant to the original post.

We have no power to our cabin, and one of the guys brings a portable CPAP every year to deer camp and runs it on the deep cycle from his boat all weekend. It runs on 30 watts. That solar panel is more than enough.

[GigaBuist]

If it gets cold then an electric heater could be useful and that should put some load on the generator.  Doubt they would have a problem with crappy power.

Beyond that I'd second the idea of just jumping it to the car and letting that charge it.

[zxcvbob]

Some generators have a 12VDC output as well as the AC.  Honda and Yamaha inverter models for instance.

[RevDisk]

I'm well aware of that. A cell phone with a 2000mAh battery holds about 8Wh at a 50% charge efficiency and the low end of your estimate you could still fully charge 20 of them, which is irrelevant to the original post.

We have no power to our cabin, and one of the guys brings a portable CPAP every year to deer camp and runs it on the deep cycle from his boat all weekend. It runs on 30 watts. That solar panel is more than enough.

Ah, my apologies, I assumed it was a normal consumer appliance that converted 120 VAC to whatever the VDC and amp necessary to run it. Yea, the watts it eats is low enough and if it runs off a VDC voltage you can find a battery for, you could initially charge it with a battery charger and keep it topped off with a solar charger.

Only thing I'd caution is running most deep cycle batteries below 50% shortens their lifespan. Regularly running it to near 0% can dramatically shorten their lifespan. No big deal on a once a year camping trip, but it'd still be a good idea to avoid if plausible. But if the draw is light enough that you don't eat up half of the battery overnight and can charge it all day, then yep, it'd be perfect solution.

[41magsnub]

Some generators have a 12VDC output as well as the AC.  Honda and Yamaha inverter models for instance.

This one does not unfortunately.  Newer versions of the same generator have it.