Xantrex Truecharge2 Reliability?

You will have to equalize those batts when you get the PowerMax, to make up for their past neglect.

You do want a glass tube with the bobber in it, but it does not have to be "good one". I use a $10 one, eg. Just avoid those sideways arrow plastic things that are hard to operate to get the right amount of fluid in them and hold them just so and even then they are kind of wonky.

The trick is to use the same hydrometer each time to the same readings. You go with consistency, not accuracy as such. When the SG gets as high as it will go, that's your number (whatever it is) using that hydrometer. That is good enough to tell you what you need to know.

Wait till you do the equalize to get the SG as high as it will go to be your baseline SG. meanwhile just get them as charged up as possible.

With the Wet 6s at least you don't have to achieve a minimum amps charging rate like with AGMs that are down enough to take a Bulk Stage. You can use your 5 amp rate if you want on the 6s and use the time it takes.

Don't use voltage to tell you the batts are full--voltage readings can be very misleading. The SG never lies! Use SG to tell the truth.

Yeah they were both at 6.11 volts, which is just a tad under 60% SOC (6.12 is 60% according to the datasheet). Manufacturing date was January 2019. Got them from a small battery company, clearly they had not been watching/charging them enough. According to Trojan, they should be charged in storage upon dropping to 70% SOC. $300 for the pair before tax, core charge included, so hopefully I didn't get a bad deal.

Right now I'm charging them with my RC hobby charger. Like most chargers, it goes to 14.7 volts, and is not adjustable. 10 A max charge current. It ends the charge at 10% of charge current setpoint. So if I charge at 10 A as I am now, it ends absorption at 1 A. If I set it to 5 A, it would end at 0.5 A and so forth.

I haven't yet bought a hydrometer or a power supply/charger that can do full charge voltage or equalization, so it's just the hobby charger for now. That should get them fairly close to full. After I let it sit a day or two after charging the voltage should tell me, though it won't tell me if I need an equalization. Full charge is 6.37 volts or 1.277 SG (T-105 datasheet).

I will use a hydrometer to check for full charge and the potential need of equalization as soon as I get one. I found one of the good ones today at the local hardware store, the floating tube with a built-in thermometer, but unfortunately the thermometer was clearly broken as it was reading 40 °F in room temp or I'd have bought it. It was the only one with the floating tube scale they had. My guess is battery hydrometers don't exactly fly off the shelves. :D

The big thing now with the new batts is to charge them up to true full ASAP, then note their SGs. Say 1.300 or whatever.

(They will be down a little from shelf time)

That is your "baseline SG" to be your target for future recharges. If the SG does not get up to baseline SG, the batts are not full! It takes a lot of time to get to true full, so having them at home gives you that time.

CA Traveler wrote:
NO Don't remove the batteries at home, they are needed for the trailer brakes! Or as the OP suggested use a temporary battery for transport to storage.

That wasn't the OP, since I'm the OP. Someone else suggested removing the batteries, and cautioned to make sure I use a temp battery for transport to storage. I said that if I was going to remove them, I'd do it at the storage lot. Meaning we'd come home from camping, unload, take it to the storage lot, remove the batteries, come home and charge them. So just rearranging the order of things to not need a temp battery.

CA Traveler wrote:
Removing batteries gets old real quick. From the OPs usage I'd suggest a large set of cables from the TV battery to the RV batteries. This will go a long way towards significant battery charge from CG to home to storage.

This is a good idea. I bought the batteries yesterday, and yes, it will certainly get old dragging those to and from the camper. They aren't drastically bigger than a group 24 but they are way heavier!

Anyway, thanks all for the advice. I think I have a pretty good idea of what I'm going to do.

Add a modest solar system. Your batteries will thank you for doing so.

Removing batteries gets old real quick. From the OPs usage I'd suggest a large set of cables from the TV battery to the RV batteries. This will go a long way towards significant battery charge from CG to home to storage.

Add solar to finish the charge in storage. Since you often store it for a month you don't need a huge solar setup. And if it's just a few days the batteries will be fine and benefit from alternator charging as you leave storage and then leave home.

Also add a full disconnect switch for the batteries so there is absolutely no RV battery drain in storage. Wire the solar to the battery terminals so switch off and batteries get charged.

I have battery switches on both of my battery banks for storage which is covered so I can't use my solar. There is limited battery self discharge and I make sure they get fully charged once a month. And the OP uses his RV once a month.

NO Don't remove the batteries at home, they are needed for the trailer brakes! Or as the OP suggested use a temporary battery for transport to storage.

That's some good points. Maybe taking them off really is the best way to go. I suppose it wouldn't be that bad, could set everything up with heavy duty connectors so I'm not fiddling with nuts and ring terminals all the time. If I went that route I'd probably just take them on and off at the storage lot, so I didn't have to reconnect another battery for the trip to-from the lot.

I guess the only easy alternative would be some solar. Get them to 90% SOC with a rapid charge at home, then let the solar do the last 10% over the next few days.

Well, the easiest way would be to only ever camp at sites with electricity, but limits the number of available campsites drastically, especially in the busy season.

I'll need to think on this some more. Thanks all for the thoughts.

Looking at the OP's problem for charging the batts after getting home before heading to the no-power storage yard.

Rv is out on the street so how to get house power to it? Long extension cord across sidewalk all night? How far up the street to find an empty parking spot? Gen? It will take all night, so can't run the gen that long.

It will take about 50 minutes to get from 50% SOC at constant 60 amps to absorption at about 70% SOC, and then about another hour and a half to get to 90%, call it all about two and a half hours. But now you have to get to 100 from 90, which takes hours and hours. You can't get close to 100 and put them away with no Float in hopes the Float time will get them finished. They have to be at full baseline SG before you turn off the charger. Probably run out of time before the RV has to be moved.

So best way is take the batts off the rig at home and do it all there however long it takes. (wheel barrow or little red wagon job) Meanwhile you need a 12v battery in the trailer (emergency breakaway law)to get to the storage yard and run whatever there to set up.

So now you bring that 12v batt home which will be not heavy to get off the trailer into the tow vehicle for the ride home. Put the 12v batt on a Float at home too.

So that's all solved! :)

Meanwell, not Maxwell.

My rsp-500-15 does not meet its specs, it exceeds them. The voltage range they claim is well under what I measure too

As I said it will go right to 40 amps, and stay there as until battery voltage rises to the voltage setpoint I have chosen before I plugged the dc powerpoles together.
My inline wattmeter says 40 amp, my shunted battery monitor, with all loads shut off will read 40 amps, my clamp on ammeter will read 40 amps. I actually have 3 more wattmeters I can plug inline with the one hardwired onto the meanwell and all will agree within 5%. 40 amps to seek and hold any voltage between 13.12 and 19.23v, well I've never tried to get it to provide 40 amps above 16.2v

I doubt the unassisted heatsinking and the small yet extremely loud and powerful 40mm fan, by itself, would have allowed 5 years of regularly outputting 40 amps, but with it I have no fear of running it flat out.

I have added a 60mm Noctua fan blowing inward, and an 80mm fan exhausting the steel lid of the casing. These fans keep the loud 40mm fan off completely under 64F ambients even at 40 amps, but it will still come on at higher ambients when passing 40 amps for a while.

Without the extra fans the 40mm internal loud fan would cycle on and off with as little as 6 amps.

I think you have to factor in these or at least some ventilation and heatsinking modifications to the meanwell vs powermax, which leans more heavily for the powermax.

No speed control of the fan, like on PD 92xx series converters.

The heatsinking I added, visually appears to be overkill, but they do get quite hot.

As hot as it gets, I've never seen it not be able to maintain 40 amps when the loads could still ask for that much.

the existing trimpot on the meanwell is not even one of the nice blue 20 turn trimpots but one of the 3 legged 270 degree tiny pots that are super difficult to adjust precisely.

I had to completely disassemble the meanwell to get to the underside of the circuit board to remove the voltage trimpot and install wires. Doing this requires removing the transistors from the casing. The thermal grease makes this a potentially messy job. Snipping the legs of the trimpot to add wires to those legs would be better if one could manage that, access is tight.

If going for the full disassembly, have more thermal grease on hand.

I don't know for how long a pair of flooded T-105s depleted to 50% would accept 40 amps, but I'd likely want more than 40.

My 50% depleted Northstar 90Ah group 27 when new would accept 40 amps for about a half hour before reaching 14.7v. 65 amps for about 22 minutes before reaching 14.7v.

I don't run a generator to recharge so the VA is not a concern for me and the PFC nature of the Meanwell is not truly appreciated.
Fast as possible recharge times are also not a requirement of mine, but this Northstar AGM has proven to crave high amperage from a well depleted state to restore performance when lots of full or nearly full recharges by low and slow solar only had voltage maintained under load for the same Ah removed from battery lagging..

How long the battery can accept 40 or 65 amps is another observational datapoint I've been collecting since september 2014, when I acquired and started employing the Meanwell, and the Northstar was already 10 months old by then, but used more as a stating battery and cycled only when my other flooded battery was getting EQ'd which was 2x a month.
That other battery lasted ~500 deep cycles before I removed it from rv service in june 2015, but it is still going in workshop duty powering leds and fans. My Northstar then was doing double duty, cycling and engine starting while I was modifying the battery tray for a GC-15 sized battery and has been doing so alone, ever since.

The Northstar proved so able to meet my needs I never completed that battery tray project and have been been cycling and starting my engine on the same battery ever since. I can carry 66% more battery capacity, I just don't need to, or want to.

You will get a lot of philosophical answers regarding charging of batteries. some will say just get this and you will be 'just fine' and there is no need to stress these little things.

I can tell you are a tinkerer and there is appeal to modifiying things and seeking ideal, to achieve ideal as possible battery life, within reason.

I'm not trying to steer you to the Meanwell, just giving you all the info I know about it from having used it for the last 5 years as a battery charger, and a converter, and a float charger, and a maintenance charger, and yes, also as a power supply without a battery in sight. I'vwe put some hours into modifying the meanwell with more heatsinking and ventilation and the external trimpot and wattmeter, and also making sure the wiring to and from it was not stressing the circuit board receptacles. While the powermax casing is hardly as sexy as a garage charger marketed to the mass public, my meanwell is downright ugly with heatsinks and fans and wires sticking out all over the place, but its performance cannot be argued with.

If my needs changed, and I were to require more battery capacity, I would want more charger, and would get a second meanwell and parallel them. A diode or 2 might be necessary. When I parallel the schumacher they combine their amperage until battery voltage rises to the max setpoint of the schumacher, which might be 14.7v or 16.4v, as the Schumacher is an unreliable whack job with little consistency.

I have some voltage drop on the wiring so can exceed my voltage setpoint, and charging at 65 amps does raise battery temp quickly too, so I am there to keep voltage from going too high as amps taper and voltage drop becomes less of an issue. but in general I want max possible amps until 14.7v is reached. I dont want them tapering at 14.3v battery voltage because of voltage drop on the wiring, even though it likely makes little difference in charge times to truly full, or battery longevity.

While i say i set it to 14.7v then pthen attach powerpoles, If I am paralleling the schumacher I start the schumacher first and get it to do 25 amps, then plug in the meanwell and will crank the voltage dial as high as needed to insure 40 amps output, as there is some shared wiring to the battery along which the voltage drops at high amperages.

There are also some cheaper 30 and 36 amp Megawatt power supplies that are similar to the meanwell if the $ per Amp is the endgoal, and cheapo 30 amp powersupplies with adjustable voltage which appear visually identical to the megawatt available for as little as 18$, I had one but it had no thermal or current overload protections. It was rated for 30 amps yet would exceed 38 amps. and did so for 17 minutes when I got tired of twiddling the voltage pot to keep it under 36 amps, but close to that, before it released the magic smoke, and I ordered the meanwell minutes later.