Replacing my auxilary battery

wrcsixeight · Mar 14, 2013

Your Dometic will likely only pull 3 .5 amps maximum.  It all depends on the resistor they added to the thermostat circuit to speed up the compressor for faster cool downs. For long term use the fridge is more efficient at 2000 (minimum) rpm.  Higher speeds can suck the heat out of things faster, but requires more electricity to do so. It could be anywhere from 2.5 to 5.xx? amps with a Danfoss bd35 compressor. Danfoss recommends having the fridge have its own feed wires right to the battery and fused as close to the battery as possible.  They don't want is sharing a buss with other devices.  They want minimal voltage drop in the wiring from battery to controller.  Ciggy plugs are hardly ideal from a connection and resistance point of view.  I'd recommend a dedicated quality Ciggy plug receptacle for the fridge, wired with 10awg, and fused right at the battery. Hooking a heavily depleted  jumper pack upto a ciggy plug receptacle will melt the fuse every time, because the battery is so hungry for amps it will take everything the wiring can pass initially.  Even a 12 amp hour AGM common in jumper packs, when depleted, can ask for 50+ amps briefly.  It is hard to charge these properly by paralleling it with the engine battery.  the best thing to do when they are super depleted and you cannot plug in, is attach the alligator clips to the engine battery itself with the engine running and let them quench their thirst for a few minutes before trying the double male ciggy plug outlet charge them from inside the van. When you get your Van back, run new ciggy plug receptacles to the new house battery, and leave the dashboard ones running on the engine battery, or moves these as well to take power only from the house battery.   I try to never deplete my engine battery at all and everything is hooked right to the house batteries, all lighting, all ciggy plugs take from the house. If the outlet is  truly dead from your dual jumper pack charging attempt, check your main fuse panel, and if those are still good, then the wiring to the plug is compromised somewhere. The male ciggy plugs have fuses in the end of them too, if you have the dual male plugs for charging the jumper packs, check for a fuse on each end.

caseyc · Mar 14, 2013

Yeah, it seemed like a good idea at the time to recharge the jumper batteries through the 12 volt outlet, haha!  Those 2 batteries are now currently home and plugged into the AC wall outlet getting the proper charge it deserves.   I will pass your suggestions to the van conversion shop when I take the van in next week. I will pretty much rely on them to do the right thing, and I will let them know what my power needs are so they can hopefully accommodate. Since you have multiple batteries for your own usage, where do you place them all?  Are some or all the batteries inside your van/vehicle? Or all placed in a special compartment underneath the van?   I would love to have multiple batteries installed, but I'm told there is limited space underneath the van for a compartment to house the battery.  I literally have nearly no space inside the van which is already filled up with a bed and other stuff.  I don't really want to place batteries underneath my bed frame for obvious safety reasons. EDIT:  I asked the conversion van shop if they can install a Group 31 battery instead of a Group 27 battery, but was told a Group 31 battery won't fit in the housing underneath the van because it's too large. I only know about a Group 31 battery based on a quick Google search.  Oh well, that was worth a try!

wrcsixeight · Mar 14, 2013

I have two batteries below the floor behind my driver's seat, inside a cabinet.  There is an access hatch that screws down, but I got to crawl half inside the cabinet whose door way  is ~ 22 inches square. Those AC wall chargers for the jumper packs are actually very slow, which is fine, if time is of no matter. I used to hook an older 12a/h agm from a jumper pack to my system to charge from the solar, but even that old abused and depleted battery could blow fuses if it was dead enough.    Have the conversion company go over the system they install thoroughly with you, and take notes, and have them draw up a wiring diagram of what they are installing. I'd ask them what product they are using to isolate the batteries with the engine off.  Some 'isolators' use Diodes, so the electricity can only flow in one direction, from alternator to battery.  Sounds fine but the Diode also drops charging voltage by upto .7 volts, significantly slowing down the recharging of the isolated battery. Solenoids are better at recharging the house battery.  Some solenoids are voltage sensing, some are time delay, and some other types are latching relays that require energy to make or break the contact, but not to hold the contact as solenoids do. http://www.bluesea.com/products/category/Automatic_Charging_Relays

wrcsixeight · Mar 14, 2013

A group 31 is only slightly larger, like 3/4 inch longer at 13 inches. It is no taller, and not much wider, perhaps 1/4 inch.  It does not really store that much more electricity( 5-10 amp hours at most).  It sounds like they already fabricated the battery holder for a group 27. I made that mistake as well.  Made it to house 2 group 27's.  If I made it 1 1/8 wider, I could fit in 2 group 31's.  I could modify it, but won't. But as it stands, I might go with less overall amp hours next time I replace the batteries.  I do not really need 230 a/h in my current usage, and I am trying to lighten the Van, as my around town MPG is inadequate.

caseyc · Mar 14, 2013

Since you need to access your 2 batteries through the hatch, does that mean you don't place anything on top of the van floor? My conversion shop mechanic inspected my van, and told me various modifications need to be done in order to accommodate a housing compartment underneath the van.   For example, there is a side wall that is in the way and needs to be cut into, plus one of the "running walls" of the outside of the van needs to be cut or modified because that too is in the way.   Mind you, my van is a conversion van that has "stuff" already added to it, as opposed to a bare cargo van that would have been much easier to do things.  The mechanic will need to spend extra time doing custom work to add the battery and housing underneath the van.  Plus my previous car stereo guy had already installed a now dead battery along with cabling, and some or all of this previous stuff needs to be taken out or modified. Of course, all that means extra labor cost, but at least I was already told that up front.

wrcsixeight · Mar 14, 2013

When My  Battery hatch is in place, I can put whatever I want on top of it.

caseyc · Mar 15, 2013

Wow, is that all hardwood floor in your van? Very neat and organized! My conversion van has carpeting that matches the entire interior.  What kind of van do you have, is it a cargo van, low/high top?  If I had to do everything all over again, I might have gotten a high top van, and one with lower miles, later year model.  Oh well, I only paid $3,000 to a used car dealer for my 1995 Ford E150 conversion low top van with 155,000 miles on it.  But I spent a couple thousand more on repairs and upgrades, plus much more for all the electronics, and now even more for a larger better auxillary battery.  My van is becoming a wallet hog for expenses!  I had no idea I would keep spending and spending when I first got started with this van, haha! Well, holy smacks Batman, guess what a new upgraded alternator would cost?  $2,200.00 !!  The conversion van manager received word from the shop that specializes in doing truck/van work said it would cost $2,200 for a more powerful alternator (2x power), plus all the upgraded cabling, and including labor. Unreal!!  Fortunately, the van conversion shop didn't make any obligations, so we are going to skip the new alternator entirely, and see how it goes with my current alternator after installing the new and improved auxillary battery.  The conversion shop will also install an additional dual 12 volt outlet receptacle towards rear of van that will run off the new auxillary battery.  Can't have enough 12 volt outlets is my new motto!  Especially after burning out the fuses from my existing 12 volt outlet from the van floor next to the driver captain chair.  I won't be recharging any more car jumper batteries from the 12 volt adapter, haha! Thanks for letting me know a Group 31 battery isn't much more power versus a Group 27.

wrcsixeight · Mar 15, 2013

My flooring is just Home depot's cheapest laminate snap together fake wooden flooring.  It has held up okay, but if i were to do it again I'd use real tongue and groove hardwood laid diagonally across the valleys, and fully sealed all 4 sides before laying it down. The alternator upgrade is overkill for just one additional battery.  Sure it might have lasted longer and been less stressed, but in terms of actually being able to recharge the  AUX battery, it would not have improved things much at all. Now if you were running the microwave, and the engine to offset its battery killing requirements, then the larger alternator might have been able to supply everything the microwave was using, where as your current alternator might be maxed out and allowing depletion of the battery while using the microwave. You should have the Conversion company wire up a fuse block.  These are great for later adding circuits, and also great for organizing the wiring.  have the one dedicated ciggy plug wired right to the battery for the fridge, but have the rest on the fuse block. I have one like this

and I still have a few open circuits to use .  You just run a wire to the threaded bolt from the battery(+) and this fuse block can distribute protected circuits to whatever you decide to add. Also a Buss bar for the Negative wiring near the fuse block makes wiring easier and appear organized. With an Aux battery, there is no need to carry the jumper packs, except to jump other people who do not have an auxiliary battery. I have 7 ciggy plug receptacles, two up front, two in the middle and 3 in the back, and sometimes find 6 of them in use at once.  I also have other connectors able to handle higher currents spread around the interior.  All of these run to my added ATC Fuse block and are powered from the house batteries over 10 awg wiring.

I use these for my air compressor and battery charger.  I originally intended to use nothing but these in place of ciggy plugs, but ciggy plugs only take one hand to connect, these take two.  I have found some of these connectors to be defective and heat up when passing large currents, but others could pass 25 amps all day long and get only slightly warm. Anyway, I sense you are intimidated by wiring projects, when in fact they are very easy.  The hardest part is running the wires where they will not be exposed.  Joining the wires or adding connectors to wires is also pretty easy.  You will benefit greatly from these modest skills if something goes wrong when you are on an outing.  Looking at somebody else's wiring is intimidating.  If you added it yourself you will know exactly what each wire is and where the circuit runs.

caseyc · Mar 15, 2013

Ah, thanks, I feel better about skipping the upgraded alternator now, especially for that outrageous cost.  You have 7 12volt outlets?  Wow, I think I will request for even more now!  The thought just now occurred to me to install an extra dual 12volt outlet receptable on the left side of the ceiling next to the wall (about middle of the van).  That way, I can easily plug things like a 12volt fan without having a lot of long cords to deal with. My impression is that it doesn't cost much to add extra 12volt outlets, so I will ask for 2 separate dual 12volt outlets (1 for the rear of van, and 1 for the ceiling if possible).  Yes, seeing all that wiring would intimidate me if I had to do it myself. I already have too many cords connected from AC outlets going to the inverter, plus USB cords galore as I have many USB powered devices. By the way, I don't use those 2 "8 in 1 batteries" for jump starting a vehicle engine, it's really more for charging portable devices.  The big momma battery I use for jumping a car battery is the Sears 1150 battery (per below link) that has lots of power and multiple outlets for charging devices (eg: 2 110volts, 2 12volts, 1 usb, plus other features. Sears 1150 car jumper battery: <a href="http://www.sears.com/diehard-platinum-portable-power-1150-with-jumpstarter-air/p-02871988000P" rel="nofollow" target="_blank">http://www.sears.com/diehard-platinum-portable-power-1150-with-jumpstarter-air/p-02871988000P</a>

wrcsixeight · Mar 15, 2013

http://www.amazon.com/Blue-Sea-Dual-Charger-Socket/dp/B0082CXEI8. I installed one of the above, and am considering adding another in the back. I have 7 ciggy plug outlets, and another 6 of the other 25 amp capable connectors spread out around the interior.  I hate having exposed wires to get in the way.  I also have 2 more ciggy plugs, on switches and hidden, with the phone chargers taped inside them. You'll find that carrying around those extra portable power packs is a waste of space when you have a dedicated auxiliary battery, especially one being fed with the alternator and solar. I had one from long ago, before I had extra batteries, but would never bother with one today, much less draggin around 3 just to have enough outlets for my devices. Any device designed and marketed to do many different things, performs each task barely adequately.  One could buy individual devices with more capability for less money, they would not be in the same container with a convenient carrying handle though.  That is really what you are paying for with these jump packs with built in inverters and air compressors, convenience.  The inverter is likely only capable of half what it claims and is a sloppy square wave.  The air compressor will overheat in 5 to 10 minutes, and hopefully it shuts itself down before damaging itself due to overheating.  The internal charger is super slow, and likely takes 12 hours to get it to 85%, where ti will flash the fully charged green light.  That 15% extra could take another 24 to 36 hours at the low charging voltages the internal chargers safely put out. A 22 pounds, that 1150 likely only has a 12 or maybee 18 amp hour battery inside it. That is hardly a lot of power, and the cold cranking amp figures are grossly inflated.  If your engine battery was truly dead, these would be next to useless in cranking over a V8 engine. http://www.amazon.com/UB12120/dp/B003NN7A3Q The only reason I would carry a jumper pack is so I would not have to drive somewhere to assist somebody else who ran their battery down, and lately I tell them I'll jump them if they  have cables, and can push their vehicle to mine, if I am set up at camp, and I also don't let them touch the cables. If they were wise enough to run their battery dead, then they are wise enough to hook up the cables backward and blow out my alternator or engine computer.  It happens all the time. It was a while ago, but the last time somebody wanted a jump when I was in Baja, I had them bring me their battery, paralleled it to mine, and in about 15 minutes transferred enough amps to it that they were able to start their engine.

caseyc · Mar 20, 2013

Hi Wrcsixeight, I was hoping to have the new battery installed this week, but it won't be until next week as they are waiting for the solar panels to arrive.  In the meantime, I already removed all my appliances and cords to clear a path for them to drill a hole and install a battery housing.  Geez, I hope I don't have to do this again anytime soon, it's such a pain!  A thought occurred to me.  Is there any way to charge the new auxillary battery through an AC outlet cord?  For example, I sometimes stay at a campsite that has full RV hookups including an AC charging outlet.  Would I be able to somehow plug an electrical cord from the charging outlet directly to the auxillary battery to recharge the battery?  Is such a thing feasible?  Just a thought. As for the Sears 1150 car battery jumper, I've been using that for years.  I used to have a car that had a bad connection whereby the battery would drain.  After having called AAA Roadside Service too many times to simply charge up my car battery, I finally bought a jumper battery so I didn't have to call AAA Service anymore.  That battery (along with a couple other different models) have been useful on a number of occasions.  I've also used that battery to charge up other people's dead car battery.  Very handy device to have around.  I should start charging for this service, haha!  I keep an extra jumper battery around at home in case of an electrical power failure, since the battery has a built-in flashlight, plus outlets to charge up my cell phone, laptop, etc.  I have also entertained myself with the thought of buying a generator, but I don't have enough room to store something that big.  I had even done research on *propane* powered generators (as opposed to gasoline powered) after seeing news reports of Sandy Storm victims trying in desperation to fill their gas containers at gas stations.  Turns out too many gas stations could not pump gas, even though they had gas, due to no electrical power to pump the gas out of the hoses.  Wow, who would've known in advance that would pose a problem?! Do you have a generator?  If so, what type (gas or propane)?  Where do you keep a generator if you have one?  Casey

bee · Mar 20, 2013

I am not sure if I missed it when scanning this thread, but you might want to consider a real battery monitor like a 2025-rv tritronic monitor(needs shunt bought separately) .  It will actually calculate the % of battery charge accurately, unlike most others.  It can do other things as well, but that is the main one.  Then If you see your battery drop to 50% you know you must charge asap. http://www.solar-electric.com/trtmbamosy1.html For charging from a wall outlet I use an iota iq4 charger.  You can just plug it in and forget about it.  It charges fast and then switches to maintain so it doesn't overcharge.   http://www.bestconverter.com/-DLS-Series-12-Volt_c_144.html Propane vs gasoline generators.  The benefit of propane is you don't have carburator issues.  If gasoline sits in the generator unused for any length of time it might not run right and the carb may need cleaning.  If storing the generator inside propane would be a plus since it doesn't stink like gasoline.  I would look into a suitcase style trifuel honda or yamaha. This link has a link in it to generator sales where they can be bought pre installed, not endorsing the company or anything. http://www.airforums.com/forums/f448/tri-fuel-kit-adpt-for-honda-2000-genset-etc-60343.html

wrcsixeight · Mar 21, 2013

Converters like Iota and Progressive dynamics take 115ac grid power, and provide enough current to both charge the batteries, and run every 12 volt device at the same time. The difference between a battery charger and a converter, is the battery charger is portable and comes with battery clamps.  The converter is designed to be hardwired to the battery, with cables you provide yourself.  Many converters can be used as 12 volt dc power sources, without a battery hooked up.  Do not try this with a standard battery charger. Both just plug into a regular outlet and most are fully automatic.   The converter can handle cycling loads.  An Automatic battery charger will likely get confused by the fridge compressor cycling on and off, or other loads, and turn itself off. I am currently using a Schumacher charger as a converter semi hardwired to my house battery bank.  It only handles the cycling loads on the 12 amp setting.  The 2 or 25 amp settings cannot be used with my DC only fridge running, and even smaller loads when turned off will cause the voltage to spike and the charger to go into error mode.  Its fan is loud. I plan on getting a Progressive Dynamics pd9260 or an Iota dls-55. http://www.bestconverter.com/ My depleted batteries can ask for more amps from my alternator than the belt can handle when damp. a 55 or 60 amp converter plugged in for 15 minutes would remove a huge load from the alternator and belt, and much more quickly and fully recharge the batteries with enough time. Lots of opinions out there saying slow charging is best for a battery.  perhaps this is true, but not if one does not have enough time to slowly charge a battery back up above 80%, or to 100% at least weekly.  My batteries always behave better the night after I feed them 90+ alternator amps first thing in the morning for 5 minutes or so, however long my drive is, then let the solar take over, compared to just solar all day long, even if the monitor indicates both methods brought the batteries upto 100%.  I call it battery quenching, and it is my opinion that batteries like it. I've never considered a generator.  I do not need that much electricity, I'll use that much sometimes, but only when I am plugged into the grid. Bee makes a good point with the battery monitor.  I have one compatible with my solar controller, and it is an eye opening tool to monitor battery consumption, and how much all DC appliances requires over a given time span, or AC appliances run off the inverter. It has taught me a lot about how batteries charge, and how charging sources charge them, yet ignorance was bliss too.  At least till I killed another battery, and/or alternator in a most inconvenient location. Your looking at ~200$ more for this device, and for it to monitor alternator current, all the vehicle grounds must be run through a shunt before going to the (-) battery terminals.  Without it being wired so, it will be inaccurate in reporting battery state of charge.

caseyc · Mar 25, 2013

Here's an update. I'm finally taking the van in today to the van conversion shop to have the new battery and solar panels installed! I've also created a PowerPoint diagram to give to the shop so they can better envision the items that need to be completed.  See attached below.

caseyc · Apr 5, 2013

Update here. I finally got back my van from the shop. They did a first rate job of installing a new much larger auxillary battery underneath the van in a separate housing. They also added a larger 2,000 watt inverter. Plus they added 2 solar panels on the roof each collecting 20 amps of solar energy to trickle charge the new auxillary battery.  Plus they added 4 more 12 volt adapters along the 2 window-sills on left side of the van.  Now all my electronics work again!  

wrcsixeight · Apr 5, 2013

No solar panel that could fit on a van roof could output 20 amps, and no way could 20 amps be considered a trickle charge which is generally under 2 amps. I suspect with all your rooftop cargo boxes, you got two 20 watt panels, which will be about 1.5 amps each in perfect conditions, and that would be a trickle charge, and do very little to fill the void that your 2k watt inverter will suck from the battery.

caseyc · Apr 5, 2013

Ahh, yes, yes, must be 20 watts for each panel. Duh!  I have 2 rectangular panels in the back of the van roof to the left and right sides of the Thule box supported by a Yakima MegaWarrior basket.  The best I'm hoping for is for the solar panels to trickle charge the new auxillary battery to top off while the van is parked for days in a row.  I don't expect the solar panels to give enough power for the various electronics.  One day, I might decide to remove the rear Thule cargo box, and that would free up half the van roof top thereby allowing for much larger solar panels.  But for now, I prefer the extra storage room of the cargo boxes versus the extra power of larger solar panels. Unfortunately, everything is a compromise.

caseyc · Apr 9, 2013

Wrcsixeight, Here's a picture of the solar panels on the top rear of the van roof. A rectangular solar panel is on the left and right sides of the Thule cargo box.  Each panel is supply 20 watts of power, which I have noticed is juuuuust enough for trickle charging the new larger auxillary battery.  I've been testing the trickle charge, and noticed that one day the aux battery (with engine off) will be at 12.5 volts, then the next day it will be at 12.6.  Obviously not much of a difference, but at least that tells me that aux battery is getting charged each day while soaking up the sun.  Also, because of the solar panels, I now have more confidence for leaving some devices connected to the 12 volt adapters. I previously used to disconnect devices from the 12 volt adapter for fear of draining the battery, but I now have the convenience of just leaving stuff plugged in. Casey

caseyc · Apr 9, 2013

Here's a picture of the new auxillary battery and inverter setup.  You can't see the aux battery since it's underneath the van floor in a separate housing, but the new aux battery is below the black enclosure.  The black wall enclosure is housing a new 2,000 watt inverter, a Sony PS3 Playstation, fusebox, and I believe part of the bass subwoofer.  The box on the right hand side of the pic is the 10" box enclosure for the bass amplifier. You can't see it, but a total of 4 additional 12 volt adapters are installed along the window-sills of the left side of the van, and these adapters are drawing power from the new auxillary battery.  It's amazing how these new additional 12 volt adapters have greatly contributed to the ease of power cord management!  I used to have power cords going from the front of the van all the way to the rear, which was getting out of control.  But now, power cords are easily managed and more organized due to the new additional 12 volt adapters.  Geez, I should have installed even more 12 volt adapters, haha! 

psytechguy · Apr 9, 2013

Having your panels shaded like that is going to cut way down on their efficiency.

ANY shade, with even a small part of the panel covered, will effect them.

Your panels should be on top with nothing, i.e. vent/fan cover, luggage carrier, etc. dropping shade across them.

Lot's of info on this, just Google "solar panel shading."

Replacing my auxilary battery

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