48V system charge settings?

Artboard

Here's my situation: my system has never worked right, even though it's been installed for three years. Here my system specs:

32 rolls S-530 series 4000 batteries Arranged in four banks of eight, for a nominal 48 V system.
One Xantrex XW6048 hybrid inverter/charger, one Schneider Electric Xantrex XW6048 hybrid inverter/charger wired in master/slave configuration.
Three Apollo solar turbocharger and PPT battery charge controllers wired in master and two slaves configuration.
36 Kyocera KD180GX-LP solar arrays, wired in three arrays of 12 each.
A 24 kW Kohler generator for backup.

Batteries are set to charge at a maximum of 80 A, which is max for the Apollo configuration.
Absorb is set for 58V for :2:00 hrs.
Float is 55V

I equalize every 60 days or so. Equalization is set for 2-3 hours @ 62.5V. Since I am in the mountains, and in a valley with a short solar day, I augment my solar Equalization with my generator.

This Xantrex boxes give me an error message of DC overvoltage midway through my equalization cycle, cutting out the generator. The system continues to equalize via all solar, because it has a 62.5V equalization setting. After equalization, the system floats, but the specific gravity of the cells in the batteries are low. I checked many cells in the battery bank, and most of them have specific gravities of 1.225-1.250. Almost none of them have specific gravity of 1.265.

What are the proper settings for my system?

Vic

Re: 48V system charge settings?

Hi Art ..

Am unfamiliar with your Solar Charge Controllers, but it appears that if you are limited to 80 Amps max from the CCs, you may well be throwing away about 30 amps of charge capability from the PV array. Three CCs and you can ONLY charge at 80 Amps ... How can that be ??????? ?? ?

Seems that the batts are not getting fully recharged. You could try increasing the Absorb time to about 6 or so hours, and increase the Absorb V to about 59 V or so.

The Float voltage is quite a bit too high -- should be set to about 52.6, altho, you may never get to Float with a much longer Abs stage.

You have four strings of batteries. This is probably most of your problem. Parallel strings do not share current well. And as things progress in time, the sharing generally gets worse and worse. You might try looking for strings of similar SG batts, might be able to find two strings of fairly good batts, and EQ them until the SGs of each cell get closer to each other. Normally EQ is not a timed event. It is done when needed, based on variation in the SGs of 20-30 points. The SG of the bank is monitored during the EQ, and EQ is terminated 30-60 minutes after the SG of the lowest cell stops rising. OR when the batts get HOT -- 115 degrees F max.

If this works, you might try to EQ the other batts, perhaps using Surrette's recommendations for a Corrective EQ.

Chargers must have temp sensors on each one unless they can share a common one. SGs need to be temperature compensated.

There are many many things that must be considered. If you do not have the Surrette Battery Manual, you can find it here:


http://support.rollsbattery.com/solution/categories/688/folders/10484/articles/654-battery-user-manual-flooded-agm

Your short Solar day and Winter on the way does not help things. More Later Good Luck, Vic

niel

Re: 48V system charge settings?

i admit i am not familiar with the xantrex inv/charger to comment on the overvoltage you are getting, but you may want to pick apart what everything is set to and review everything over and over to see if the culprit pops up at you. i am assuming you tried xantrex for the problem and have gotten nowhere. my guess might be that the 3 80 amp controllers may have a voltage being outputted that the 6048s see as being to high and there may be an adjustment needing to be made on the settings.

the 4 paralleled battery strings will be hard to keep in balance and is most likely why you need to eq often and maybe you should try it every month and extend the time up to 4hrs minimum and maybe even to 6hrs to see if things start to improve.

Cariboocoot

Re: 48V system charge settings?

Battery bank: four parallel strings of 400 Amp hour batteries; total 1200 Amp hours. If those four strings are not connected correctly current sharing will be uneven on both charge and discharge. See the Smart Gauge diagrams here: http://www.smartgauge.co.uk/batt_con.html

Also this bank wants 120 Amps peak current @ 48 Volts, which needs about 7.5 kW of array. You've got 6480 Watts. It should work, but is a little bit low. Probably maximum current is around 100 Amps.

Are you sure those charge controllers aren't 80 Amps each? Limiting the total charge to 80 Amps would be just a 6% peak charge rate. Add some loads while charging and you will have deficit charging periods.

At 58 Volts the Absorb setting is a tad low. The time of 2 hours is also suspect, depending on how deeply you discharge the battery. If you can measure the current to the battery during Absorb with no loads do so. If it remains above 3% of the battery capacity (36 Amps) the Absorb time is too short.

You need to fully charge and EQ those batteries manually until you see no more improvement in cell SG. Otherwise what you are doing is turning expensive batteries into scrap metal. 62 Volts should be sufficient for EQ, and leaving off that half Volt may keep the XW from dropping the gen. Normally when EQ is needed and you're short on sun the thing to do is Bulk up with the gen ASAP in the day and let the solar deal with the EQ.

Couple of suggestions you probably won't like:
1). Consider replacing those charge controllers. If they really do limit your panels to only 80 Amps total this is indeed a waste of panel.
2). Re-evaluate your load requirements. Do you actually need 28 kW of stored power? That is quite large. Considering your short solar day you might benefit from a higher panel to battery capacity ratio. Something along the lines of 800 Amp hours instead of 1200 may make all the difference (providing you can get full charge current).

Vic

Re: 48V system charge settings?

Well, Marc, to me the four strings of 400 AH batts is actually closer to 1600 AH, altho, you probably are using the Imperial AH.

Am reasonably certain that the XW OV in EQ is from the Solar input. Usually, on other systems that I've seen, the Solar EQ V can be reduced a bit to allow its contribution while not upsetting the Inverter's contribution.

The SW+ Inverters had a propensity to regulate V during Charge and EQ by dumping current into AC terminals, which could cause the Genset V to go overvoltage and no longer qualify, get dropped, and start the cycle again. I hope that the XW inverters do not do this.

RCinFla seems to know all about things like this ...

One additional problem with SOOOooooooo many parallel strings of batts, is that one has AALLLLLLLllllllllllllllll llllll of those individual cells to check for SG, fill with water and so on. THis often makes the system manager fail to do proper SG checking of ALL cells, and monitor water levels etc. Have seen some multi stringed banks where it was physically difficult to even see into some of the batts. Very unsanitary IMHO.

YMMV, GL, Vic

niel

Re: 48V system charge settings?

"Am reasonably certain that the XW OV in EQ is from the Solar input. Usually, on other systems that I've seen, the Solar EQ V can be reduced a bit to allow its contribution while not upsetting the Inverter's contribution."

vic,
this is my suspicion too, but it's hard to say for sure sitting here.

offgrid me

Re: 48V system charge settings?

If the batteries are cold the cc will up the eq v to compensate. I have gotten this same DC over voltage warning with eq voltage set at 62v when I ran an eq in 40F weather. Anything over 64v and it triggers the warning.
Ned
ps no inverter or generator involved

Cariboocoot

Re: 48V system charge settings?

Vic wrote: »

Well, Marc, to me the four strings of 400 AH batts is actually closer to 1600 AH, altho, you probably are using the Imperial AH.
Vic

Yes, 1600 Amp hours! Which makes the situation even worse.
I was jumping the track thinking about chopping it down to three strings, then two, and doing all the math simultaneously. That'll learn me (no it won't; it hasn't yet).

This only reinforces my suggestions of re-evaluating loads and such. I mean we're looking at a need for 160 Amps and nearly 10kW of array! The 100 Amp rate available slips to 6.25% rate and if it is limited to 80 Amps that is a mere 5%; the bare minimum you'd want.

I'd strip out half the batteries just to see if the system performed better. By which I mean re-assemble a bank with half the capacity using the batteries with the highest SG.

BB.

Re: 48V system charge settings?

But, back to the error--Do you have an actual voltage measurement when the error occures? From other posters on the forum--There is a 72 VDC Max voltage fault which will shutdown the XW Hybrid inverter. Is that what is happening?

Also, a low rate of charging current (less than 13% rate of charge) should make voltage faults less likely (you should have a very hard time getting up to 72 volts with room temperature battery bank at 5% rate of charge).

There is the possibility of sulfating batteries reducing capacity--Have you seen any evidence of that (low capacity, low specific gravity, "bad cells", batteries that "recharge too quickly", etc.)?

By the way, welcome to the forum--Hope you find the solution(s) to your problem.

-Bill

Artboard

Re: 48V system charge settings?

The way the 3 Apollo Solar Turbocharger MPPT Battery Charge Controllers (Master with 2 slaves) are set, perhaps each of the 3 controllers is putting out 80A. Does that seem more reasonable?

Made all of the changes to Absorb and Float as advised below.

I am running the generator right now for an EQ, since the sun went down. I checked all the cells (tedious, takes 2 hrs) and some were pretty low (one cell @ 1.150, 5 others at 1.175, most at 1.200, some at 1.125, with a few at 1.250. I am keeping a spreadsheet with all the initial data, and will update the same data post-EQ.

It is around 55°F here during the day, colder at night.

Vic wrote: »

Hi Art ..

Am unfamiliar with your Solar Charge Controllers, but it appears that if you are limited to 80 Amps max from the CCs, you may well be throwing away about 30 amps of charge capability from the PV array. Three CCs and you can ONLY charge at 80 Amps ... How can that be ??????? ?? ?

Seems that the batts are not getting fully recharged. You could try increasing the Absorb time to about 6 or so hours, and increase the Absorb V to about 59 V or so.

The Float voltage is quite a bit too high -- should be set to about 52.6, altho, you may never get to Float with a much longer Abs stage.

You have four strings of batteries. This is probably most of your problem. Parallel strings do not share current well. And as things progress in time, the sharing generally gets worse and worse. You might try looking for strings of similar SG batts, might be able to find two strings of fairly good batts, and EQ them until the SGs of each cell get closer to each other. Normally EQ is not a timed event. It is done when needed, based on variation in the SGs of 20-30 points. The SG of the bank is monitored during the EQ, and EQ is terminated 30-60 minutes after the SG of the lowest cell stops rising. OR when the batts get HOT -- 115 degrees F max.

If this works, you might try to EQ the other batts, perhaps using Surrette's recommendations for a Corrective EQ.

Chargers must have temp sensors on each one unless they can share a common one. SGs need to be temperature compensated.

There are many many things that must be considered. If you do not have the Surrette Battery Manual, you can find it here:


http://support.rollsbattery.com/solution/categories/688/folders/10484/articles/654-battery-user-manual-flooded-agm

Your short Solar day and Winter on the way does not help things. More Later Good Luck, Vic

Artboard

Re: 48V system charge settings?

I did re-examine everything, including the generator charging settings. The generator was set to charge at 90% of capacity, so I backed it off to 60%, and it seems to be running fine. Load is not so great on generator.

Artboard

Re: 48V system charge settings?

CaribooCoot - Wow! My bank is not wired up anywhere close to the way your wiring link indicates, and I have 32 EXPENSIVE batteries! System is wired up as shown in diagram #2. No, I'm not in the business of making scrap metal, either. I'll be buying wire and rewiring soon!

What drives our load is not normal household usage. Main electrical draw is a 400 gal electric hot tub. When the pumps and heater are going when the 4500 sq ft normal house loads are going, we need 7.5 kW.

Artboard

Re: 48V system charge settings?

Hi Vic,

Yes, I know it is a drag to check, refill, and measure SG in 96 cells. After the system architect/installer built the system, he left without giving me instructions on how to maintain the system. None of the solar folks in the Southern Colorado area where I live seem to be very reputable, and no one will drive this far into the mountains for a service call.

I learned about SG in batteries the hard way. When the system kept dying quickly even after getting "fully charged" last spring, I finally discovered the Surrette battery manual, checked my batteries, and discovered 5 fully "dead" batteries. Surrette advised me how to do the emergency EQ, and I was able to save 4 of the 5 batteries. Had to buy 1, which was bad, but better than 5! Now I check SG regularly. Bummer is that when the batteries are in the system, I have never had SG readings at 1.265 or more.

Cariboocoot

Re: 48V system charge settings?

Artboard wrote: »

CaribooCoot - Wow! My bank is not wired up anywhere close to the way your wiring link indicates, and I have 32 EXPENSIVE batteries! System is wired up as shown in diagram #2. No, I'm not in the business of making scrap metal, either. I'll be buying wire and rewiring soon!

What drives our load is not normal household usage. Main electrical draw is a 400 gal electric hot tub. When the pumps and heater are going when the 4500 sq ft normal house loads are going, we need 7.5 kW.

With four parallel banks you're best off using method #3: every bank connected to bus bar/common point with equal length wiring.

7.5 kW hours per day? On 48 Volts that's about 157 Amp hours. With a 25% DOD that would be a 628 Amp hour bank minimum, and at least 3600 Watt array.

niel

Re: 48V system charge settings?

that is a severe mismatch by the sgs indicated. you may need to try to charge individual batteries up if you can. there may be some sulfation there too. i sure hope none of them are ruined. try to use very little power while trying to bring your batteries up. understand this may take many tries at eqing and quite some time. that is good you are now tracking the batteries maintenance info with the sgs measured. don't forget to keep them properly topped with distilled water as any exposed plates will spell impending doom for that cell.

Artboard

Re: 48V system charge settings?

Hi CaribooCoot - Setup #3 was what I was thinking as well. Where do I buy the terminals, wire and buss?

Also, there is another unusual wiring setup I discovered, once I was studying my wiring scheme.

My two XW6048s are wired in parallel, sort of. Each of the 6048's has a positive lead connected to a positive terminal on the 48V battery banks #1 and #4, yet the negative lines are both connected to the same negative terminal on 48V battery bank #4. Based on what I read in the wiring diagrams, this is also problematic.

I also saw that a few battery terminals were pretty heavily corroded. Should I disassemble those and clean them? Last time I did this I put conductive electrical grease on the connections. Does this really help?

The 7.5kW is peak demand for the hot tub, and usually only happens for 20 min or so, depending on usage and outside temps, like in the wintertime with lots of snow around. I forgot to mention that this is a second home, and only gets used once every six weeks or so. Usually the hot tub is set to SLEEP mode and the temp is turned way down, resulting in the water temp dropping to 60°F or so and the filter motor only cycling once a day for an hour or when the water in the lines gets below 40°F, and the heater only goes on when the filter is running (low speed). When we arrive at the house, we wait until the sun comes up to bring the hot tub back to usable temperature. Question: Should we just run the generator when we bring the hot tub back up to temp, or is it OK to rely on the solar? Alternatively, have you any recommendations for solar power (heat at least) for a hot tub so I can convert this one?

Artboard

Re: 48V system charge settings?

My only power here is from generator and solar. To charge an individual battery up, should I remove it from the array, plug a car battery charger into a running generator (or house system?) and charge it that way? I took the five "failed" batteries out of the array and did the emergency EQ as recommended by Surrette from my other home - which is on the grid.

I did an insufficient EQ yesterday, and then tried another EQ tonight. Will do one more tomorrow (before I head back to the home on the grid to vote.) SGs are improving across the board, but still a few weak spots.

vtmaps

Re: 48V system charge settings?

Cariboocoot wrote: »

With four parallel banks you're best off using method #3: every bank connected to bus bar/common point with equal length wiring.

Artboard,
Cariboocoot's advice to rewire your battery bank is a very good way to make the best of a bad situation. But four parallel battery strings is still a bad situation. Read more about it here: http://forum.solar-electric.com/showthread.php?14674

--vtMaps

Cariboocoot

Re: 48V system charge settings?

Yep; you've got a mess.
The terminals connecting to the batteries are corroded? Say 'hello' to extra resistance in those connections. Got to be cleaned up at the very least.
The two inverters aren't connected to the same battery points? Well one will have a different Voltage available than the other. Guess what that will do.

Take the battery bank apart. Connect one 48 Volt string to one XW and another to the other one. Straight forward one string each, all with clean, tight connections. Fire up the generator and charge them fully. Then try EQ on just those strings. Use the gen for the whole sequence if you have to: you're trying to save the batteries and the fuel cost is not important. Keep trying an EQ cycle until you see no further improvement in SG. At that point, no matter what the reading is, you're done. If the cells don't come up to around 1.265 and aren't consistent, the batteries are done too. (Do not power any loads from the inverters while doing this.)

7.5kW is a lot of power to deliver. But you should not need a 1600 Amp hour battery bank to supply that for 20 minutes. I guess someone calculated that on a basis of 10% draw (about 160 Amps). How much do you use in Watt hours per day?

There are better ways of heating water than electricity! Almost anything is better, in fact. You're seeing first-hand why. For lots of ideas about solar-thermal applications, you can't beat Build It Solar: http://www.builditsolar.com/

Blackcherry04

Re: 48V system charge settings?

Tip of the Day : if you have 1/4 turn caps with the Vent Holes in the side they can be inserted into the wells 180 deg. out of phase. When you turn them the 1/4 turn to lock them, that allows the Vent holes to either face toward the Lug connection or away from it. If Vent Hole is facing away from the lug you will get a lot less corrosion, if any. It's attention to Detail, I know it sounds like a pain, but once you get use to doing it, it becomes habit.

2) I use a lid off a 5 gallon bucket and you can sit your caps on it while you water or check SG's. It's non conductive and you can sit it on top of the batteries as you work, I do a row or a string at a time. it's easy to rinse off when your done.

3) For corrosion resistance I use " Marine Engine Fogging Oil " It's in a spray can and cheap and works great. It will foam up and is creeping, a little bit will do you, It comes with the little red extension and you can get it just where you want it.

H2SO4_guy

Re: 48V system charge settings?

I use these http://www.solar-electric.com/40x38studrin.html terminals to build my own cables out of 4/0 fine-stranded cable and they work very well. If they corrode too much, I just scrap off the corrosion, clean with baking soda and water, then tin them again in a little metal cup of solder. Works great for me and I solder the ends on rather than crimp them. I did buy a crimper from NAWS, but don't use it too much. I always let NAWS know that I am purchasing from them because they have the forum and I vote with my wallet!

Artboard

Re: 48V system charge settings?

Thanks BlackCherry. Ok, now I'm going to really sound dumb here, but I must learn.

1. Never really paid attention to the hole. Makes sense, though (duh).

2. I have lots of 5 gal can lids. Easy solution.

Again, another embarrassment: I've been sloppy with acid on the top surface of the batteries during the the SG checking, since it is for so many cells and I'm leaning in over the bank. I just get tired! This last time I removed all 96 caps and left them open during EQ to monitor water needed and boiling activity, and sealed them up after 2 - 6 hour EQs. All the batteries were very messy afterwards. Once I have resealed the batteries with the caps, should I clean and rinse the battery surfaces with water or a baking soda solution?

3. I'll find some Marine Engine Fogging Oil. Did not see it on NAWS.

Blackcherry04 wrote: »

Tip of the Day : if you have 1/4 turn caps with the Vent Holes in the side they can be inserted into the wells 180 deg. out of phase. When you turn them the 1/4 turn to lock them, that allows the Vent holes to either face toward the Lug connection or away from it. If Vent Hole is facing away from the lug you will get a lot less corrosion, if any. It's attention to Detail, I know it sounds like a pain, but once you get use to doing it, it becomes habit.

2) I use a lid off a 5 gallon bucket and you can sit your caps on it while you water or check SG's. It's non conductive and you can sit it on top of the batteries as you work, I do a row or a string at a time. it's easy to rinse off when your done.

3) For corrosion resistance I use " Marine Engine Fogging Oil " It's in a spray can and cheap and works great. It will foam up and is creeping, a little bit will do you, It comes with the little red extension and you can get it just where you want it.

niel

Re: 48V system charge settings?

yes, wipe it up, but do so with just a slightly damp rag or rags. if you go to neutralize the acid on top with baking soda you must use extreme caution that it will not be able to enter the cell area.

the guys will probably instruct you more specifically if i fail to cover this properly, but the use of a hydrometer should be done with care. it should be kept clean and when you put it in and draw on the electrolyte push it back into the cell and draw on it again so it will better represent what is in that cell rather than being diluted some from distilled water used in cleaning or a possible false reading from residual acid from another cell. do not be in such a hurry with it, not just for accuracy and cleanliness, but for safety too. it is after all acid.

Artboard

Re: 48V system charge settings?

OK. Wish I was at my mountain place all the time, but my day job required me back in the city. Heading out again this weekend to get my system squared away as best I can, and will do so until I get it fixed and I understand it completely. (I'll have a new side business helping others in my valley on solar who are also killing their batteries due to the poor advice from the local solar guys.)

Before I left, I changed the wiring from the 6048s to the battery bank. The bank was all still connected in parallel, but I connected the 6048 positive leads to the positive connections on banks 1 and 3, and the negative leads to the negative connections on banks 2 and 4. With the new voltage settings and times for absorb and float, and just unoccupied home loads on it for these past few days (side-by-side energy star Whirlpool fridge, kegerator, and internet modems and routers), it will be interesting to see the SGs on Sat.

I will upload my SG spreadsheet (thank God for iPads!) showing all SGs post-three 4-6 hr EQs over a 3 day period Sun - Tue. Many of the batteries came back well, but not all, which is why I switched the wiring. Note these readings were taken with a auto parts store hygrometer, which sometimes required 4-5 tests/cell just to get a reading I believed. Hopefully the $50 hygrometer is better.

Power usage: We have a big "cabin" (4500 sq ft) and a big family (8 kids, 5 married, three grandkids) who often show up at the same time. When occupied, we heat with wood stoves, but lights, TVs, stereos, ice makers, toasters, hair dryers, kitchen mixers, blenders, etc., may get turned on simultaneously, not to mention the energy star Whirlpool large capacity washer and dryer. We stopped using the dishwasher almost completely, except during daytime when nothing else is running. Occasionally the electric hot tub will kick on in middle of all this, especially in the winter with kids (and snow rolls).

When I take the bank apart and EQ single banks as advised, must I also reconfigure the 6048s to run independently, or still in a master/slave configuration during the battery restoration process? Should the 6048 battery bank capacity settings be reduced from 1600 AHr to 400 AHr each, too, or reduced to 800 AHr if the 6048s are still config'd as master/slave, even though they will be independent form each other?

Once I get two banks restored to health, I'll do the other two banks in a similar fashion.

The original config was a single 6048 on this entire 1600 AH, 48V array, intending for the Kohler generator kick on if the current demand from the hot tub exceeded the 6048 output capacity. Instead, the system just went completely dark. Sometimes we'd arrive on scene with a Fault message from the 6048 that had been there for a few days - week. After a few of these surprises in the wintertime, I told the original designed to get me the second 6048 and wire it in, which he did. This stopped the fault messages, but the batteries are still slowly dying.

What is my optimum/optimum wiring and panel config for this place? Assume I get the hot tub water heater converted to solar, too. Can I keep the hot tub pumps and blowers as wired (electric), or is something else better there?

Cariboocoot wrote: »

Yep; you've got a mess.
The terminals connecting to the batteries are corroded? Say 'hello' to extra resistance in those connections. Got to be cleaned up at the very least.
The two inverters aren't connected to the same battery points? Well one will have a different Voltage available than the other. Guess what that will do.

Take the battery bank apart. Connect one 48 Volt string to one XW and another to the other one. Straight forward one string each, all with clean, tight connections. Fire up the generator and charge them fully. Then try EQ on just those strings. Use the gen for the whole sequence if you have to: you're trying to save the batteries and the fuel cost is not important. Keep trying an EQ cycle until you see no further improvement in SG. At that point, no matter what the reading is, you're done. If the cells don't come up to around 1.265 and aren't consistent, the batteries are done too. (Do not power any loads from the inverters while doing this.)

7.5kW is a lot of power to deliver. But you should not need a 1600 Amp hour battery bank to supply that for 20 minutes. I guess someone calculated that on a basis of 10% draw (about 160 Amps). How much do you use in Watt hours per day?

There are better ways of heating water than electricity! Almost anything is better, in fact. You're seeing first-hand why. For lots of ideas about solar-thermal applications, you can't beat Build It Solar: http://www.builditsolar.com/

Artboard

Re: 48V system charge settings?

Here is a list of the SGs from my 1600 AH 48V system.

Red cells indicated their SGs were less than 1.200 (min was 1.500) when I started EQs. Most recovered pretty well.

Artboard

Re: 48V system charge settings?

Will do. Had to squeeze bulb multiple times to get consistent readings anyhow.

Damp rags with baking soda solution, or just water? Water sounds smarter, but there is a lot of acid on top of everything now.

niel wrote: »

yes, wipe it up, but do so with just a slightly damp rag or rags. if you go to neutralize the acid on top with baking soda you must use extreme caution that it will not be able to enter the cell area.

the guys will probably instruct you more specifically if i fail to cover this properly, but the use of a hydrometer should be done with care. it should be kept clean and when you put it in and draw on the electrolyte push it back into the cell and draw on it again so it will better represent what is in that cell rather than being diluted some from distilled water used in cleaning or a possible false reading from residual acid from another cell. do not be in such a hurry with it, not just for accuracy and cleanliness, but for safety too. it is after all acid.

niel

Re: 48V system charge settings?

if you want to stay on the safer side of things just use the rags and wring them out after rinsing before rewiping. it is risky to have baking soda near a battery if you don't know what you're doing.

stephendv

Re: 48V system charge settings?

Artboard wrote: »

I did re-examine everything, including the generator charging settings. The generator was set to charge at 90% of capacity, so I backed it off to 60%, and it seems to be running fine. Load is not so great on generator.

I'm not familiar with the Xantrex 6048, but there should be 2 settings relating to the generator current: the first should tell the 6048 what the max output of the generator is, and the second should tell it what the max charging current for the batteries is. If you've only programmed the max charge current, but not the max output of the gen, then the 6048 could be trying to draw too much from the generator causing it to slow down/under volt error or under freq error and disconnect.

It also sounds like there are some problems with the Xantrex starting the generator. The way you designed the Xantrex + generator system is correct, and that generator should be able to pick up any additional current draw that the Xantrex can't handle, and it should start at low battery SoC. If those two features aren't working then there's probably something wrong with the Xantrex programming.

For the overvoltage problems, check the temperature compensation on the Xantrex as well as the Apollo chargers- should be the same for both. If it's still occurring, you could try decreasing the EQ voltage on the Apollos slightly.

Blackcherry04

Re: 48V system charge settings?

Batteries are sure messy, I buy my Baking Soda in 5 lb. bags from Sams Club. You really do not need a lot soda mixed in a water solution to neutralize the acid. I mix it in a Spray Bottle, like 4 table spoons to a Qt of water. It's easier to direct it and won't leave such a mess. After the water evaporates it will leave a light residue of the Soda on the tops of the batteries cases, but it's still active and helps. I also carry a bucket with the same mix of soda and water so I can mop up any excess.

Tip:

1) After you un-lock the top, as your lifting out of the well, tilt the cap 45 deg to the right or left, tap it twice on the lip of the well and all the condensation and acid that has collected on the bottom of the cap will drop off back into the cell. The bottom of the caps will be loaded with acid and it'll drip off on the top of the battery making a mess. The proof it works will be less drips and less acid on the Lid you set them on.


Why tap twice ?, since someone asked. The Acid is in Micro droplets on the bottom of the cap. These are the size that are released during gassing. The First Tap causes the Micro droplets to condense into a larger droplets and the second tap will cause them to fall from the bottom of the cap back into the well. I know there is someone else that can post a better explanation.


These may sound like goofy details, but after 30 years you kinda know what makes your life easier. Doing the same thing over and over and getting the same bad out come doesn't make sense.

Artboard

Re: 48V system charge settings?

The 6048 allows me to select the generator model from a lookup table, and then adjust the percentage output of the generator. Gen switched off again at 60% output, so I backed off to 50%, which went Ok for an hour or so, then kicked off again. Yes, the generator was being loaded up heavily, and the generator was kicking off with under voltage and under freq errors.

The Xantrex programming has always been suspect. It is certainly the main brains of the system. I have known something has been wrong with it almost since day one, because the fuel gauge display on the remote monitor was always reading full charge, when I knew it was not fully charged.

Not sure where the temperature compensation is on the 6048, although there is a default battery temperature setting on the 6048 where the batteries temp is set to “cold.” I do not recall a temp compensation setting on the Apollos.

stephendv wrote: »

I'm not familiar with the Xantrex 6048, but there should be 2 settings relating to the generator current: the first should tell the 6048 what the max output of the generator is, and the second should tell it what the max charging current for the batteries is. If you've only programmed the max charge current, but not the max output of the gen, then the 6048 could be trying to draw too much from the generator causing it to slow down/under volt error or under freq error and disconnect.

It also sounds like there are some problems with the Xantrex starting the generator. The way you designed the Xantrex + generator system is correct, and that generator should be able to pick up any additional current draw that the Xantrex can't handle, and it should start at low battery SoC. If those two features aren't working then there's probably something wrong with the Xantrex programming.

For the overvoltage problems, check the temperature compensation on the Xantrex as well as the Apollo chargers- should be the same for both. If it's still occurring, you could try decreasing the EQ voltage on the Apollos slightly.

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Re: 48V system charge settings?

I buy baking soda the same way. Good suggestions. I have plenty of rags.

Appreciate the attention to details, too, like the double tap to release drips.

Blackcherry04 wrote: »

Batteries are sure messy, I buy my Baking Soda in 5 lb. bags from Sams Club. You really do not need a lot soda mixed in a water solution to neutralize the acid. I mix it in a Spray Bottle, like 4 table spoons to a Qt of water. It's easier to direct it and won't leave such a mess. After the water evaporates it will leave a light residue of the Soda on the tops of the batteries cases, but it's still active and helps. I also carry a bucket with the same mix of soda and water so I can mop up any excess.

Tip:

1) After you un-lock the top, as your lifting out of the well, tilt the cap 45 deg to the right or left, tap it twice on the lip of the well and all the condensation and acid that has collected on the bottom of the cap will drop off back into the cell. The bottom of the caps will be loaded with acid and it'll drip off on the top of the battery making a mess. The proof it works will be less drips and less acid on the Lid you set them on.


Why tap twice ?, since someone asked. The Acid is in Micro droplets on the bottom of the cap. These are the size that are released during gassing. The First Tap causes the Micro droplets to condense into a larger droplets and the second tap will cause them to fall from the bottom of the cap back into the well. I know there is someone else that can post a better explanation.


These may sound like goofy details, but after 30 years you kinda know what makes your life easier. Doing the same thing over and over and getting the same bad out come doesn't make sense.