Battery recharge after storage information

[idroba]

I thought I would make a post on the state of charge of the batteries in my two trailers, as well as my TV after sitting for 5 months here through the north central Idaho winter.

I leave the batteries in the rigs, and totally disconnect them, clean their tops, and otherwise do nothing to them. They have no chargers on them at all. They sit that way for the 5 months I am gone. The trailers are outside, under a carport, the TV is in the basement garage. The average temp here is generally about 30 F over the 5 month period. We had two cold spells when it went down to 0 F for a day or two and a couple of weeks of 10 to 20 F weather.

When I returned last week I measured the voltage of each battery. The TV (Jeep GC) read 12.74 volts, the Argosy with a pair of Costco 6 volt golf cart batteries which are about 3 years old now read 12.71 volts and the two original type 24 batteries which came in the 2014 FC 20’ and are about 10 months old now read 12.65 volts on each battery, individually. All measurements were taken with a Fluke professional quality meter.

The voltage readings alone indicate that the batteries had not self discharged as 12.6 volts to 12.7 volts generally is thought of as a state of full charged.

However, I have monitoring equipment that can measure the charge current when put back into service to see if they will take any more charge. Both trailers have Progressive Dynamics 3 stage smart chargers, a PD 9245 in the Argosy, and a PD 4645 in the Airstream. I replaced the original Airstream charger within 3 weeks of purchase.

There is a shunt style ammeter in the circuits of both of the trailers, the Argosy has a digital current readout in Amps, and the Airstream has a Tri Metric meter, which also indicates current flow very accurately.

On the Argosy, when the batteries were reconnected and first plugged in so the converter/charger was operating, the initial charge was 3.7 amps, in two minutes that dropped to 2.7 amps, in 5 minutes it dropped to 2 amps, and in 12 minutes it dropped to 1 amp of charge. In 30 minutes it dropped to 0.5 amps.

So, the batteries took virtually no charge to bring them back to full after 5 months of sitting.

On the FC 20’, the Tri Metric meter showed less than a 1 amp charge when first plugged in, and that tapered to .5 amps in 10 minutes. Again, after sitting for 5 months the batteries took virtually no charge at all. In fact the Tri Metric readings showed "fully charged" before I turned on the converter/charger at all.

Remember the cautions I have made in the past about this. The batteries must be fully disconnected from all loads by pulling one terminal from the post (I disconnect the negative terminal generally). If you have a recent Airstream the Use/Store switch does not do this completely, it leaves some things like the propane detector connected. The battery(s) must be completely disconnected from any possible load.

The second thing is the batteries must have clean tops. If not clean, a small amount of current will travel through the surface dirt and cause slow self discharge.

The third thing is that the batteries must be fully charged to begin with, and only a good quality 3 stage charger (such as the Progressive Dynamics ones, or other brands) can do that. The original equipment converter/chargers in the Airstream trailers are NOT three stage chargers). I recommend that the charger be connected (trailer plugged into line power) for 48 hours prior to disconnect. You cannot expect batteries to give you good service if they are not fully charged when put away for the winter.

So, rejoice knowing you do not have to physically remove your batteries in the fall, store, periodically charge and then replace in the springtime. follow the three steps above and things will be fine in cold climates. In warmer climates you may have a somewhat larger self discharge but I doubt it will be significant. But in warmer climates you can use your Airstream all year, so the batteries should be OK in any event.

Remember: Charge fully, clean tops, disconnect completely, wait for spring, reverse.

[Bigskyrider8]

I've had my Airstream 23 FC now for three weeks (new) and I'm already to buy a new converter. I'm somewhat amazed that Airstream places a single stage converter in their units?

[idroba]

It appears that Airstream uses the Parallax Charger/converter because Parallax is the only manufacturer who makes the integrated 120 volt/12 volt/converter/charger package in one unit. Parallax does not make a 3 stage charge unit. So, Airstream is stuck with what they can purchase. If they didn't use the Parallax, they would have to go back to their old system with a separate 120 volt panel, 12 volt fuse panel, and the third part, a converter/charger. That would cost considerably more money.

Parallax makes a huge number of these integrated units for the RV industry and I am sure they are a low cost item. Airstream does not have enough volume to demand Parallax produce a decent converter/charger section just for them.

So, the only way to get a good 3 stage unit is aftermarket, as many have done, including myself. Progressive Dynamics makes a replacement unit (46xx series)which fits right in the original enclosure, and also has a superior fuse block system with LED lights which indicate if a fuse has blown. Cost is in the $200 range.

[idroba]

BTW, one thing that Airstream could do easily is to upgrade the battery system they supply as standard equipment to a pair of 6 volt golf cart batteries in series for a 12 volt system. That would give a much more robust battery at a modest cost. The only other thing they would need to do is to make the battery box about 2 inches deeper for the slightly taller batteries.

I am in the process of doing that this upcoming week. Just picked up two golf cart batteries at Costco in Missoula yesterday. I am not yet sure just how I will modify the battery box height. Several posts have been made on what others have done.

[Jammer]

The self-discharge rate varies over the life of the batteries (older=worse) and is also affected by temperature (warmer=worse).

I keep mine on a charger

[mefly2]

Originally Posted by Bigskyrider8

I've had my Airstream 23 FC now for three weeks (new) and I'm already to buy a new converter. I'm somewhat amazed that Airstream places a single stage converter in their units?

No need to get in a hurry, but contact Lewster on this forum. We intend to do the same next summer.

[RankAm]

Idroba, thanks for your post. It is good to know that, with proper treatment, the batteries can be left alone over the winter. My 1956 Flying Cloud (totally gutted now) stays in Montana through the winter, but I escape to a warmer climate. I will remember your post when I finally get to completion of my renovation. Hank

[mstephens]

How much work is it to change out the Parallax for a Progressive Dynamics 4600? Is this a few hours work?

[idroba]

The change out is fairly simple. I went to a 4645 (45 amp) rather than a 4655 (55 amp) version as a 4655 will overload my 1000 watt Honda inverter generator. Since the 45 is a slightly different version, the instructions I had to follow were not quite right, and it took me a bit of time to figure out just how to do it best. Still, I think 2 hours from start to finish would be plenty of time. The most difficult thing is changing the fuse panel to the much superior one PD includes in their kit. You have to disconnect and re connect all the branch circuit wires to make that part of the swap right.

If you are changing to a PD 4655 vs. the Parallax the instructions should be spot on, and I don't thing anyone not scared of a few wires will have any issues.

[Morgan guy]

It has been about a year since I converted to the 4655 and the worst problem that I recall was having to fight to make one connection to the red power terminal because I did not have a lot of slack in the original wire. I finally was able to get it connected and have not had a problem since. My AS stays connected the whole time it is in storage and I have not had my batteries boil dry as they did with the original inverter.

[RT66]

I've been following this thread with great interest as well as searching through the forum on the topic. Consider this is coming from someone that doesn't understand the difference between a watt and an amp, no explanation need here. So given rdroba's post below -

Originally Posted by idroba

It appears that Airstream uses the Parallax Charger/converter because Parallax is the only manufacturer who makes the integrated 120 volt/12 volt/converter/charger package in one unit. Parallax does not make a 3 stage charge unit. So, Airstream is stuck with what they can purchase. If they didn't use the Parallax, they would have to go back to their old system with a separate 120 volt panel, 12 volt fuse panel, and the third part, a converter/charger. That would cost considerably more money.

A couple of questions come to mind:
If the PD unit is such an easy swap why doesn't Airstream install the PD by default? Does the PD4655V provide the same basic functions, 120 volt/12 volt/converter/charger, as the Parallax? Or is there some additional component needed to get what Parallax offers in one unit? Slightly confused.

[mstephens]

Originally Posted by idroba

The change out is fairly simple. I went to a 4645 (45 amp) rather than a 4655 (55 amp) version as a 4655 will overload my 1000 watt Honda inverter generator. Since the 45 is a slightly different version, the instructions I had to follow were not quite right, and it took me a bit of time to figure out just how to do it best. Still, I think 2 hours from start to finish would be plenty of time. The most difficult thing is changing the fuse panel to the much superior one PD includes in their kit. You have to disconnect and re connect all the branch circuit wires to make that part of the swap right.

If you are changing to a PD 4655 vs. the Parallax the instructions should be spot on, and I don't thing anyone not scared of a few wires will have any issues.

Bingo. I am totally FINE with wiring of all kinds. My concern was getting into a lot of mechanical crawling around or going underneath, or heavy work. Wiring is my thang. Thank you so much for the info.

[mstephens]

Originally Posted by RT66

I've been following this thread with great interest as well as searching through the forum on the topic. Consider this is coming from someone that doesn't understand the difference between a watt and an amp, no explanation need here. So given rdroba's post below -



A couple of questions come to mind:
If the PD unit is such an easy swap why doesn't Airstream install the PD by default? Does the PD4655V provide the same basic functions, 120 volt/12 volt/converter/charger, as the Parallax? Or is there some additional component needed to get what Parallax offers in one unit? Slightly confused.

My new found understanding is this: Parallax (stock AS) charges at only ONE voltage, 13.6V. This is two little for fast charge, and too much for maintenance charge and so the batteries get boiled if on shore power too long (days and weeks). The PD4655 features THREE charge rates and intelligent charging software. 14.5V for heavy charging of drained batteries, then 13.6 for topping off, then, a slight trickle type charge. This means your batteries can deliver more power and they will last longer.

As to why AS uses the cheaper one....well, I think that is self explanatory.

[idroba]

Originally Posted by RT66

I've been following this thread with great interest as well as searching through the forum on the topic. Consider this is coming from someone that doesn't understand the difference between a watt and an amp, no explanation need here. So given rdroba's post below -



A couple of questions come to mind:
If the PD unit is such an easy swap why doesn't Airstream install the PD by default? Does the PD4655V provide the same basic functions, 120 volt/12 volt/converter/charger, as the Parallax? Or is there some additional component needed to get what Parallax offers in one unit? Slightly confused.

The Parallax combines both a converter/charger/12 volt fuse panel with a 120 volt circuit breaker panel which has the main CB plus 3 or 4 branch circuits. To my knowledge, no one else makes such a system, including Progressive Dynamics. When you swap out the better three stage PD converter/charger you are only replacing the 12 volt side of the Parallax system, leaving the 120 volt parts in place. If Airstream did it at the factory they would have a big pile of Parallax converter/chargers, as well as a unit that Parallax would not warrantee, nor would it pass the original UL approval granted to Parallax, and it would cost Airstream considerably more money and time to do it. So, it is just not possible for Airstream to factory replace part of the Parallax system. Now, if someone else made the same kind of system Parallax does, but with a better converter/charger, and at a reasonable price, I believe Airstream would change suppliers. But for now their only alternative is a separate converter/charger, 12 volt fuse panel and 120 volt breaker panel, the way they did in the past. That is quite expensive in both parts and building cost, vs. the all in one Parallax system with it's poor quality single stage converter/charger.

Parallax could solve the problem by making a decent three stage converter/charger available to RV manufactures, but they don't. Why is a question, but probably it is a price point situation. They make thousands of the all in one units (virtually everyone in the RV business uses them) and I am sure they are inexpensive to produce. If there is little demand for a better one, and no willingness to pay for it, Parallax won't make it. Airstream's quantity of purchase is minor compared to the total numbers that are made.

Since Airstream never seems to comment on things my explanation is a bit of speculation, but it fits the information we can see. I am satisfied that it is pretty close to the truth.

I am rattling on here, but one reason Airstream uses the same old noisy AC, energy inefficient units everyone else uses is that there simply is no one who makes a quality, quiet, energy efficient one. So, Airstream is stuck with what is available on the OEM market. They are not going into the AC business and producing their own. They only make about 50 RV's a week as I understand. A market for 2500 a year special AC units is not enough for anyone to build to.

[mstephens]

What agreat explanation, Idroba. Thanks.

[lewster]

Actually, there are several other manufacturers of integrated 3-stage converter/AC breaker box/DC distribution combinations that I have seen. IOTA Engineering makes a nice combination unit and so does WFCO. While I would not give you 2¢ for anything from WFCO (read Chinese), the IOTA unit has a very good converter with it.

Parallax actually does make a fairly good converter…..the Paramode with TempAssure. This is actually a 3-stage charger with temperature compensation…….the ONLY converter that has temp/comp. This is a very important feature, as any standard converter's output is pegged at a standard of 77ºF and does not vary with battery temperature. (I don't use this product as I have heard of reliability problems with them…….YMMV!)

This puts you in the position of undercharging your batteries in low temperatures (even with 3-stage charging) and over-charging them in hot conditions, as charge voltages are dependent on battery temperature.

Also, there is no converter made that has adjustments for battery bank size and type. This is also necessary as different types of batteries (liquid lead acid, sealed and AGM) have different voltage requirements for proper charging. Another factor is the length of the charging stages. Bulk and absorb charges should be regulated by battery bank size and should not be one size fits all.

There is a solution though……….. INVERTER/CHARGERS! These products (like the Magnum Energy selections) have great 4 stage chargers, are fully adjustable for size of battery bank, duration of the absorption charge, type of battery (charge voltage profile) AND are fully temperature compensated. Plus, you get the added benefit of having a fully integrated inverter to produce 120VAC from your batteries when off-grid. And BTW, They are made in the USA and are all fully field serviceable.

It would seem to me that a premium (or so often described as such) item like an Airstream trailer would include inverter/chargers as standard equipment (like many other high end RVs do), along with a quality battery (NOT Interstate batteries). It is amazing how many new owners opt for these upgrades soon after taking ownership and never look back.

I hope Airstream is listening!

[RT66]

Thanks idroba, great explanation. It is all clear to me now.

[idroba]

Originally Posted by lewster

Actually, there are several other manufacturers of integrated 3-stage converter/AC breaker box/DC distribution combinations that I have seen. IOTA Engineering makes a nice combination unit and so does WFCO. While I would not give you 2¢ for anything from WFCO (read Chinese), the IOTA unit has a very good converter with it.

Lewster, could you point me to Iota's combination unit? I did a web search and search of their site and could not find any combination 120 volt AC distribution panel and 12 volt DC distribution panel listed. But then it could be hiding somewhere.

We need to have something to beat Airstream over the head with so a good system might be included in future production.

[Kyle401]

Progressive Dynamics has combination units in 30A 120VAC and 50A 240VAC with their 3 stage charge wizard.

[lewster]

Originally Posted by Kyle401

Progressive Dynamics has combination units in 30A 120VAC and 50A 240VAC with their 3 stage charge wizard.

These is some of the units I have been seeing on newer RVs. IOTA also made a similar unit, but it seems that they have trimmed their offerings and have discontinued their power center line, which looked a lot like the PD units. I see more WFCO power centers, especially with deck mounted converters, but the PD units seem to do the job nicely and have the better quality converters with integrated Charge Wizard. Still not perfect, but way ahead of the Parallax battery burners!