The converter may have got them back to full charge, but the issue is keeping them there on a float for so long after that without exercising them.
I don't know if any converter can do that. Some folks doubt the value of that little shot of higher voltage (14.6 or 14.4 depending on the brand of converter) that some converters do every week or so (often called the 4th stage or misnamed as "equalizing")
Others say their converters keep their batts just fine for many years. The missing info is how often they go camping or how long their float times are between camping to make valid comparisons of these claims.
All I know for sure is what works for me, which is to follow that US Battery advice. I have the usual converter that will do 14.x, plus I have another charger that will do 15.x. This lets me do that US Battery charging profile on my 6s.
We have had several discussions here about RV converters being unable to do the recommended battery charging profiles the battery makers are putting out. Work-arounds vary, but I doubt you could get a warranty claim through when the converter is not broken.
You can get just one charger that will "do it all" but these are more expensive and require you to do some hands on charge profile creation choosing settings and timing of stages etc.
If the charger is not fully charging the batteries, how would I test or verify this? Best Converter site says Boondocker has a 3 year warranty. Mine is just over a year old.
It is not the converter that is not working properly as designed. The batts need to be taken care of as described in that US Battery link posted earlier.
The converter can help with that. You might want a second charger that can do over 15v so you can do that too, which the converter is not designed to do with its 14.6 limit.
255w of solar just keeps up with our 3.2 cu ft fridge with about the same power requirements as the proposed 4.5 cu ft fridge, during a string of mostly sunny days. That is with a four battery bank.
If the fridge is cycling on half the time and it is half cloudy during the day, and it is half day and half night, then you have the solar needing to do twice what the fridge uses at night to stay even in a 24hr period. One overcast day and you are behind and might never catch up till you get shore power or have a generator and charger as well as solar.
If you have a generator and charger and lots of time allowed to run the gen if solar conditions are not so good, you can get by longer. Even if you had twice the solar it would not help if it is overcast.
Having a 120v fridge is very challenging for off-grid! Your rig has to be able to carry that generator and charger along, and IMO more than two batts so there is some reserve for when the sun is not shining. How much solar is needed is too scenario-dependant to be exact about. IMO 170w is not going to keep up, but then it depends on how long you will be camping before the batts get down to 50%. You lose some every day, so how many days "depends"
The 120v fridge requirements dominate everything, and makes camping off grid too much of a nail-biter IMO. If at all possible, have a propane fridge!!!!
The PowerMax will only do 15 minutes of 14.6 if the batts are not down very much (same as an Iota for that) and then do 13.6, which is what the OP has been seeing. Disconnected from 13.6 he sees 13.1 which is normal.
To stay at 14.6 past that 15 minutes the batts have to not hit 14.6 themselves right away. They need to be down more, probably under 75% somewhere so they will get up to 14.6 in however long that takes before dropping to 13.6. Which is why I said to get them down to 50% first and give them a good run at the higher voltage.
The batteries have been sitting on a 13.x float for a year and not been "exercised" with some 15v sessions every few months?
They could be reduced in capacity. You need to take them down to about 50% and then let the converter charge them fully starting with some time in the 14.6v bulk stage (which is why to take them down to 50%) until they take less than 8 amps (2 each)--deemed full-- actually maybe 98%) and an hour after that, take their SGs to see if close to 1.275.
I use a surge guard for shore power. Not needed for the Honda gen, but the Honda works through the surge guard ok, as does my inverter on "whole house". The surge guard is costly, but it could pay for itself anytime, you just don't know when, on shore power in strange places.
sounds good, thanks for the all the help. I am loving the solar, fully charged now! I keep staring at the controller, it's pretty exciting!
Better not get a Trimetric then, or you'll never get anything done! :)
I use an Eco-W with my 255w panel and Interstate 6v batts.
That 15.3 is just for a shot of finishing at the end of the usual 14.8 stage. You don't use that with the solar. Also your inverter quits at anything over 15v.
I set the absorption voltage to 14.8 and the Float voltage to 14.5 (highest it will go or else I would use 14.8) when there will not be much daylight time left after the batts reach 14.8. The batts then get some absorption time at 14.5v
(The controller goes to float as soon as the batts reache the set absorption voltage.)
When daylight is longer, so they get to 14.8 earlier in the day, I set the float voltage to 13.6 which helps keep the water in the batts
The 6s do very well with that above settings. I check their SGs to confirm that.
I tried a 24v bank with solar as a test. Worked great. The MPPT controller was more efficient doing 24-24 instead of 24-12 and it also allowed the PWM controller (no buck converter in those) to run a 24v panel which is a lot cheaper per watt than the 12v panels.
Since usually, the PWM controller is much cheaper than the MPPT, the advantage in money was to go 24v panels and PWM controller, but this requires a 24v battery bank. You have to offset that by the cost of your 24-12 converter, unless you use your existing converter as PT suggests, from that big inverter the OP wants.
In another test, running the existing converter from an inverter had about a 4 to 6 amp draw (at 12v not 24v) so that would need some solar to keep up with. AFAIK, the simpler kind of buck converter you can get for that job would be more efficient by using the 24v battery bank as source instead of 120v from inverter.
Now have my latest toy, a modified PowerMax PM3-55 for the 5er.
I have it wired to the inverter next to it in the front cargo bay all near the batteries.
It does not do the usual "stages" anymore when it has been modified for voltage adjustment. It does do the first two stages. It just stays at the set voltage.
So your charging profile is to bring the batts up from 12.x to say 14.8 (pick any number your batts like) and then it stays at 14.8 forever till you lower it to a suitable float voltage. So you have to do that yourself unless you want to Float them at 14.8 :)
I marked a couple voltages by the knob. You need to do that ahead of time, because when connected up, the volt meter will show battery voltage, and when charging, that will be lower than your knob setting until the battery voltage gets up to that.
It is something like the ones Randy sells at bestconverters.com but in this case I got it from Errin at PowerMax (who will make up a unit "to order" so to speak. You have to get his price from him and for shipping etc. ) Probably easier to get one of Randy's plus the three instead of two year warranty he offers, don't know.
This is a sort of junior edition of the 100amper I got a while back. I hope to be able to run both together for 155 amps powered by my Honda 3000, which should max out the 3000. That will do a 50-90 on my four 6s in two hours, matching the morning 9-11am gen time window at the BC provincial parks when I do any recharging needed.
You can leave the solar "on" the whole time regardless of what the converter is doing.
I like the adjustable voltage PowerMax units Randy sells. Range dial from about 12 to 15.5v. That way you can set your own preferred voltage and invent your own charging profile as to when to change the voltage from absorption to float.
That beats the Charge Wizard method which only has the three voltages to choose from, and the highest is 14.4v. You do need to be able to get at the adjustment knob but that is/can be easy with a deck mount installation.
You mentioned fan noise. With the higher amp converter you might get the fan more than you are used to with the old converter that never worked hard.
I don't have info on how much noise each brand of converter makes. There will be some fan noise when any of their fans come on, can't be helped. Keep in a well-ventilated place to reduce heat build up and so fan running time.
Parallel means side-to-side, with the end leads connected together. So you'd have the wire from the converter, connected to one end of both 30A fuses, and the other ends of the fuses also connected together to one wire going to everything else. The goal is to have half the current flowing through each fuse, basically forming a 60A fuse. If the legs are somewhat unequal for whatever reason, the current won't be evenly split, and one of the fuses would be likely to blow even under non-overload conditions or when a reverse polarity battery connection is made, followed momentarily thereafter by the other one (which would then be carrying the full current). A single 60A fuse would be simpler and better.
Series connection means end to end, the same current passing through everything. Having multiple fuses in series is pointless. Having the fuse(s) in series with the output of the converter, however, is necessary—that's just saying that the wire from the inverter goes to the fuse(s), and then the wire from the other end of the fuse(s) goes to the rest of the world.
I see now why some people have reported that only one of the two fuses has blown. The usual advice being to replace both fuses anyway, since the one that didn't blow might be "stressed"
Also this all shows how come sometimes people report their battery fuse or DC circuit breake at the battery has failed, and also the RP fuses way up at the converter have also blown.
My Xantrex inverters do not seem to have any RP protection, and will be immediately fried if you screw that up. No second chances! OTOH the portable battery chargers, converters, and solar controllers do seem to have internal RP protection depending on the model etc. Got to read the info on them to know for sure in each case.
So every RV pretty much has a fuse at each end of the battery to converter positive wire: the battery fuse and the RP fuses in the converter.
Thanks again. I wondered if those sense wires at either end of the RP fuses group had something to do with the RP protection.
Not clear why the single fuse outside the unit should be close to the converter instead of near the battery where you would get more of the wire protected. I do want to protect both the converter from reverse polarity and the wire as usual with a "battery fuse" Or do I need two fuses, one at each end of the wire? The wire will be about three feet long in this case, but what if it were twenty feet long?
RJ, yes, I now understand your post with the single fuse being in series. I got off track when you said "they" and was still thinking about the two 30s (which are in parallel). All clear now! :)
One more try - This picture should clear things up
Why some folks says things that are WRONG is beyond my comprehension
As can be clearly seen the fuses are connected in parallel and are ONLY on the "+" output
Thank you!!!! Yes, I did know it was on the pos only, but could not figure out how the two fuses were wired up.
Any opinion why a single fuse on the output wire away from the unit would not do the same job, or is the location of that fuse circuit within the rest of the schematic what counts for reverse polarity protection (whereas the normal fuse farther out on the pos wire is to "protect the wire")?
Yes, I am using the 7355 as a shore power-only converter in the truck camper. For off-grid charging I will use a Vector 35 amp smart charger if the solar can't keep up.
Yes the reverse polarity fuses are in series with the output of the converter
Are you actually using a single voltage Parallax converter????????
Two lower cost fuses are less expensive and easier to install
Nothing more than a matter of cost for the manufacturer
IMHO A parallel connection of a fuse is STUPID at best nothing more than a cost saving that the comsumer pays for sooner or later
So is the first part of this correct about them being in series?
I understand how one fuse is in series with the one wire it is protecting, that is just normal fusing.
In the case of reverse polarity fuses where there is more than one fuse ( I suppose trying to protect the converter more so than the wire?), how can they be in series? I can see how they can be in parallel and then their little group be in series with the one wire.
But then RJ sees his single fuse being in series in that inverter?
I am still not clear if there is a special reverse polarity excuse for having more than one fuse for that job. Will they blow differently than having just one fuse? Or is it just easier to find smaller size blade fuses than big ones as was suggested earlier?
If one big fuse in series is the same thing and you already have a "battery fuse" on that same wire but close to the battery, why do you need another fuse right at the converter on that same wire?
So one 30 is on each leg of a Y on the one wire and then the Y is rejoined to the single wire?
I would call that two 30s in parallel, but the talk is all about them being in series. So if they add their amps in parallel, same voltage, I could use a single 60 on the one wire? Help!!! :(
When I did this a few years ago, the inverter was on #1 cu, 18 inches from truck battery, and the truck voltage stayed near 14. This time the inverter is 25 ft away on #1 cu-al. Same 35 amp Vector.
Before, when I added more load to about 55 DCamps of Vectors, the truck voltage just couldn't stay up and it fell right off. This time, it does not fall off but just sits there steady at the lower voltage of 12.2. (so the battery will be at 12.2 instead of the usual 12.5 when truck engine off.(it still has parasite loads) (but at 1.275SG)
I was hoping that 12.2 instead of 12.5 would not matter much for an hour.