Even in the tropical paradise if Vancouver Island compared with the frozen wastelands of Alberta, in January here, I can go through 100AH a day just for the furnace at 35F outside. Never mind a bunch more AH for the other stuff.
With six batteries I need a 50-90 recharge on the second day. (In the woods no solar, and besides even in the open it is dark and cloudy then.) With no generator howinheck can I do that 50-90 and keep on camping for another two days? I like to do four days to make the trip worthwhile.
Anyway, I wish the OP would hurry up and do his four day trip and see for himself what is needed.
My MSW inverter manual warns not to use it with certain battery chargers for hand tools. Says those chargers have a warning label on them about voltages. No idea.
I would have to use the Honda gen to get some PSW since I don't have a PSW inverter. (Assuming those chargers work on normal 120v house power)
The four batts will not "demand" a limited amount of amps in bulk. Forget that notion, please :( The 440AH bank will "accept" at least 160 amps at 50% no sweat, so don't worry about that.
I am confused about this. I think it might indicate there is a solution to my problem with a 25 year old 3/4 ton GM van which is rarely driven more than 4 blocks between starts. The battery doesn't fully recharge and gradually sinks to the dreaded 12.0 volts in winter here in northern Alberta. The new alternator is supposed to be good for 90 amps. It does apply 14.4 volts to the battery. It seems to me the battery should recharge fully at 90 amps for 15 minutes after a start. If the battery does not have an internal resistance limiting its acceptance of current, what is the limitation? Is it the cable from alternator to battery? If so, I can get a second cable and double the rate of charging! Maybe the cable connectors are corroded and a simple replacement will solve the problem. Or does the 14.4 volts on the battery mean all is well with the cable?
Not up on starting battery recharging, but the 14.4 volts is good. The 15 minutes is not enough time, that's all. The van needs to be kept on one of those engine battery maintenance chargers between trips like they have for motor homes.
I use one of these (wait till they come on sale again for half price or whatever) It sits at 13.4 volts forever after starting off at 14.2 for a short time.
I was referring above to deep cycle batteries which will accept the high amps until they get up in voltage at say 75% SOC when amps will then taper for some hours before the batteries are full.
I don't know how long it takes for a starting battery to get to true full after it reaches near that 14.4 volts, but it will take a while. Also the alternator voltage drops from that 14.4 soon after starting, which slows down the recharge.
The main point is that the battery does not accept the 90 amps until it is full. It only accepts high amps till it is part full, then amps taper for the Absorption stage which takes some time.
I wasn't the Bogart I was trying to remember. Might have been a KIDD with a special remote? Just can't remember. Idea was the fancy remote did the subtraction etc so you didn't need the Trimetric ISTR.
Are these various tool batteries the kind you cannot recharge using a MSW inverter? Is that a limitation in real life for camping, if all you have is a MSW?
Just curious, as I use the hand crank issued with my back jacks. Got to be the height (depth?) of depravity to use a power tool for that simple task! :)
Solar controllers only show what the solar panels are doing, not what is going to the battery and how they are doing. Solar output goes to rig systems first, and anything left over goes to the batteries. Same with converters.
A Trimetric monitor on the batteries only shows what is happening with the batteries, including whatever the solar can provide from upstream of the Tri's shunt. You have to subtract the Trimetric amps from the solar amps to see how many amps are going to other loads.
There is a solar controller that has two shunts ISTR that does both jobs, forget its name.
The freeze-up is supposed to end tomorrow :) Anyway, the WFCO is a modern type converter and can run the rig with no battery. It can also maintain and charge the battery as required on shore power.
If you cannot trust the shore power in storage, take the batteries home and put them on a simple maintenance charger and keep an eye on them at home. If you can trust the storage power, leave them on the WFCO.
If you ever go off-grid, and the WFCO does not go into 14.4 for fast charging on generator (many won't as installed too far from the battery bank), NOW you have a problem.
That can be solved by getting a different or additional (several choices) battery charger that can be run by the generator's rated continuous VA. The new (portable is a choice) charger will do the required fast charging --two 12s will take say a 70 amp charger no problem--you can use any deck- mount converter as your portable instead of installing it.
If you do not camp off-grid except for a day or two, you just need new batteries and you are good to go using the WFCO as before.
Yes, you can recharge the batteries at home and re-install them later.
Unless the trailer is very old, it will have a decent converter in the power centre that will charge the batteries as well as maintain them. What is the model of converter you have?
Older converters did need the battery connected to act as a filter for the DC power to some of the Rig's systems, but newer (since 1998-2003 ish) ones are "switch mode" and make clean DC so they can run all your rig's systems with no battery attached at all. (The trailer still needs a battery when being towed to run the break away brakes.)
Never done that with the back jacks, but I if I did, I would use my 120v drill like some do AFAIK.
Only thing is the drill is a bit slower revving on MSW inverter than with PSW inverter/gen/shore power, so that might be an issue with the jacks, no idea.
I know that helps a lot! :)
What do you actually get from such measurements anyway? Just curious, not criticising.
I am not a full-timer, so it is not easy to understand the value of these readings. I have been off-grid for several months in a row each year for a few years with solar helping with that, but all I ever need is the Trimetric AH meter to keep me informed how things are going. Not even "need" but "nice to have" on that, since the "morning voltage" tells you everything pretty much...
Based on the little info I bother with, I can adjust the daily AH use as required, but really, if the solar can't keep up, we just crank up the generator as needed to keep the batteries charged, and don't adjust the "lifestyle" at all.
So what do you full-timers get out of Kwhs etc that you do something different if the numbers don't come out as what? Maybe there is something to learn here even if not full-timing?
A few years ago on the tow or 5er forum here, a guy changed his tires to taller ones because he thought the smaller OEM tires looked silly. Then he could hardly pull his trailer anymore :)
It all came out that the 16" tires and 4.10 gave him the combined weight pulling he needed, but the taller tires lost him 2000 lbs of pulling same as if he had 3.6 instead of 4.10.
So much for looking "kewl" :)
IMO there is no "short"--the pos touching the neg. Fuses are not blowing and wires are not melting. It does seem the pos of one is touching the pos of another. Can't tell about the neg side, but often that is "common" anyway.
The DC fuse panel should say what fuse 1 and 10 are for. What is the individual and total draw of whatever they are for? He says only two lights and the awning are affected. There must be more things on the two circuits?
15a of lights would be only five 3 amp lights, so there must be more light circuits. It seems the awning is tapped into both positives and has a neg somewhere. Or else both positives are touching (wrongly) and the awning is tapped into one of them?
The question seems to be what would happen if the OP turned on all of whatever is really on the 1 and 10 circuits at once. Can anything bad happen other than blowing a 15a fuse (or two)? Can he melt any wires? How?
Is the "short" people are talking about a short that could happen like that screw into the frame going through a pos wire, but there is no short now? If that did happen, isn't that what the 15a fuse is for? Why isn't that enough?
Both positives that are touching are individually fused to 15a and I ASSume are the right gauge wires for 15a circuits. Negs all in common say, but they don't matter AFAIK.
I am not saying it is safe for sure as is, but I have not understood what the problem could be as explained so far :( Thanks.
EDIT--warning! I don't have a clue, and am just asking, so don't ASSume nothing is wrong just because I am wondering about it!
Fuses are supposed to be sized for the wire's ampacity per AWG. If the wires to the fuses are proper for 15a DC fuses, then isn't that ok?
If somehow more amps are drawn than that, then a fuse should blow, perhaps they would both blow. As it is they are not blowing and everything works.
Is there really a safety issue here at all? It does look like "they" tapped in the awning with the lights (or vv) somehow looking for a pos and neg to connect to, and somehow got into two circuits for the pos side.
On parallel fuses, note that some inverters have twin wires for pos and neg (four wires total) If you use one fat AWG wire for the pos you can put say a 300a fuse on that OR use two thinner AWG wires and put a 150a fuse on each wire.
If one wire went, all the current would go on the other wire and blow the 150 amp fuse on it
What are the charging specifications for your AGMs? Some have a 20% charging rate limit so 250AH would be about a 50 amp limit anyway.
If they are Lifeline type you can use more charging amps. In that case your two chargers will add their amps if they are nearly the same voltage getting the batts to their similar Absorption voltage.
Then it is up to their charging "profiles" if they hold that Vabs or drop to a lower voltage right away or after a certain time, which will leave the one doing it all. (but that one might be all the batteries will accept by then anyway.)
So to help with the estimating WAGS, what exactly is this inverter charger you have (link the specs) and what is the converter model?
Of course the generator has to be able to handle the power for both chargers. Can it?
You must consider the length of the conductors and their resistance.
The positive would be copper with more resistance then a welded frame. The welded frame will have no voltage drop that you would need to consider into the calculations.
Blue Sea is most likely figuring a boat where both the positive and negative are using copper conductors.
The frame isn't quite that good, but it is usually lower R than the long pos wire run.
(To answer a question earlier, you don't need the pos and neg paths to be of equal R, but they both "count." It is the total R of them both making the circuit that matters. Any reduction in R anywhere in the circuit helps.)
I had a thread about this a while back, where I was using Salvo's method of measuring R on a path, and posted a bunch of different results from things I tried. Don't have my notes anymore on that, but it must all be in the archive somewhere.
First I tried to reduce the R on the neg side (mostly frame) by adding a second neg path using a 20 ft length of copper water pipe with wires at each end bolted on to connect with. That knocked the neg R way down, and made the amps from the converter to the batteries go up quite a bit.
So next I ran a 25 ft #1AWG cu-al jumper cable set from the battery lugs on the fuse panel by the converter inside, out the door, and up to the battery bank and clamped on. This really knocked down the R on the positive side!
With that all set up for both paths, I was able to get 56 amps from my 7355 13.8v converter to the batteries (as seen on the Trimetric)
So yes, you can make improvements and measure the results so you don't overdo it-- On that, once you get the R down to where the converter is doing its max amps, there is no point reducing the R further, since the converter can't do any more amps than its max.
As it happens, I didn't take advantage of all that! I got different chargers mounted up front close to he batteries instead. The 7355 is still there as before.
" Problem is, there are no 40amp chargers on the market anymore other than the old style stand up type with wheels. Stanley, Black & Decker used to make them but not anymore. Looks like I'll have to get something that can do 20amps at best."
Not a problem! Any deck mount converter can be your new portable charger. You just cut the end off a set of #4 (cu, not cu-al) jumper cables (or use fatter cu-al) and there are your wires and clamps.
With the various charging voltage specs of the various AGM brands, you really want a variable voltage charger you can make do anything, and since it is a portable you don't need it to do "stages" automatically.
Several AGM brands say to charge them at 14.9ish volts and then Float them at 13.6ish volts. so IMO don't bother buying a converter that only does 14.4v for this job.
I use a variable voltage PowerMax as my portable charger. They come in various amp "sizes." It acts in the same role as my 40 amp VEC1093DBD, but has 100 amps. (I can also use both and get 140 amps using the Honda 3000 gen to run them both.
Here it is in action on the trailer battery bank, plugged into the Honda up in the truck ( which goes between the 5er hitch and the cab)
Your plans didn't mention an inverter so you can live better than a tent camper :) With more time off grid, that matters.
The 2800VA generator can run a 100 amp charger or a 150 amp PF corrected charger, such as found in some bigger inverter/chargers.
With the four batteries you can run a 2000w inverter to power the microwave, toaster, etc outside of generator hours, then recharge the batts when gen is allowed. Very important for breakfast toast before gen hours!!!! :)
Options are separate 2000w inverter and 100 amp charger or a combo inverter/charger. Lots of brands to choose from.
Installation/location of these units depends on the rig's floorplan etc, to get them as close to the batteries as possible. The converter now in the rig just stays as is. No need to disconnect it.
About 4 ft of #4 each wire (pos and neg) from the 75 amper to the battery will get you the 75 amps. ( I have one of those converters)
I don't know how much longer of #4 will still get you the 75 amps, but a few less amps won't make much difference to your recharge time on 2 batteries if you have to go long. Stay with the frame for the neg--that counts as a fat short wire. Then you just need a long #4 for the pos.
Don't bother with anything less than #4 with the 75 amper.
You can use the 75 amper as a portable charger for generator charging, and leave the WFCO in as the converter for when on shore power. That way you get the short run from 75 amper to the batts. Using #4 AWG (cu, not cu-al) jumper cable ends to get the clamps is the easy way to do that.