How easy are ping batteries to maintain nowadays?

[swbluto]

I remember having the v1.5 ping batteries about 5-6 years ago, and I was pumped thinking I had a battery that was going to last 1500 cycles and 10 years. Reality set in - Variation in cell quality meant some cells had much shorter lives then their peers. The battery was as strong as its weakest link, so the battery's capacity went down accordingly (My 20Ah battery went down to 7Ah in the timespan of ~100 charge/discharge cycles). I remember trying to replace the cell, and it was a nightmare with all the duck-tape, and super fragile neighboring tabs. I think I ended up breaking a few tabs and just gave up trying (Once replacing a single cell starts breaking nearby cells, it then becomes a Hydra kind of issue. Or sisyphus, except hydra implies exponentiation.), and then switched to Lipo.

How maintainable are modern V5 ping batteries? I'm looking for batteries to run my offgrid homesite, and I might be interested in LiFePO4 if modern ping batteries are easier to maintain (I.e., replacing runt cells to ensure adequate capacity in the entire pack over time). Are they? Any experience?

 

[cwah]

Get modern 18650 that has been twice and tripple capacity... and yet are cheaper.
Charge them to 80%... which would still lead to more capacity than lifepo4 but same lifespan.

Then just get a spot welder with you and spare cells.. when problems arise just replace a string of cells.

 

[swbluto]

Get modern 18650 that has been twice and tripple capacity... and yet are cheaper.
Charge them to 80%... which would still lead to more capacity than lifepo4 but same lifespan.

Then just get a spot welder with you and spare cells.. when problems arise just replace a string of cells.

Cool, I'll have to look into these 18650. Do you know of any popular suppliers for this forum?

 

[dogman dan]

Most have less trouble, much less trouble with pings than you did.

But if you did go lifepo4, I'd think going to larger format cells, bolt on terminals, would be the way to go. Then a cell dies, you at least can just bolt in a new one.

And really, lead aint dead for stationary power. To run a house you may just want to stick with deep cell wet lead.

 

[cwah]

I had good experience with nkon. But he's an european supplier

 

[999zip999]

Where do you live ?

 

[swbluto]

But if you did go lifepo4, I'd think going to larger format cells, bolt on terminals, would be the way to go. Then a cell dies, you at least can just bolt in a new one.

This sounds intriguing. Do you know the popular suppliers du jour?

I'm not sure if Headway is the main supplier around, anymore.

Right now I live in Washington state, but I'm moving me and my business to Texas soon enough.

 

[Icewrench]

Look at packs for the volt or the leaf, might be large format cells.

 

[Rassy]

Just for interest, here are the basic changes to the BMS for Ping's batteries:

Version 1 had no LEDs, so you never knew if all the cells were fully charged unless you checked them with a volt meter at the cell group level.

Version 2 had LEDs, 16 for a 48V battery, so you could tell when the battery was fully charged. But the BMS was powered by a subset of the cells so the BMS itself would cause the battery to become unbalanced. I had two cases with relatives that I gave trikes to with V2.5 Ping batteries, and they didn't understand the importance of getting "all the LEDs lit" on a regular basis. In both cases it took a fair amount of time and effort, plus working with a "single cell charger" to get these batteries back to full balance.

Version 5 also has 16 LEDs for a 48V battery, but the BMS is powered from the full battery, so even though it will run the battery down if left hooked up for an extended period, it will not put the battery in an unbalanced condition.

I have a 3+ year old V2.5 Ping that has one LED that, even when new, always takes a fair amount of extra time to light up. I plan to do some voltage tests to verify the LED is operating properly, and whether or not it is the BMS that is causing a problem. Then I'll replace the V2.5 BMS with a V5 BMS, which I already have on the shelf. Mainly, I'm curious if there is a weak cell or if this particular BMS is draining that cell group more than any others.

So, my point is that Ping has improved the BMS over the years and the V5 should help users keep their batteries properly charged and thus avoid premature failures. This is not intended to be a plug to use LiFePO4 batteries, but just an explanation of how the Ping BMS system currently works.

 

[dogman dan]

https://www.amazon.com/gp/offer-listing/B0063Z9BC4/ref=dp_olp_0?ie=UTF8&condition=all

No idea if this is a good price, or good seller. Just an example of a 100 ah Calb lifepo4 cell. Ships from Utah.

Might be worth it to just buy similar from Alibabba though, sea shipped.

Cells like this come in 10-20-50 ah sizes. For a 12v system, 100 ah would be only 1200 ah, so not as big as 100 ah sounds.

But again, bear in mind how many cycles you'd get from 12v 200 ah lead, if you only pull 100 ah per cycle from it. My off grid friend runs his entire household from 4 deep cycle lead batteries, that he just tops up daily when he runs a generator for about an hour. While the generator is on, he can run his fridge, AC, etc all at once. His lead is a lot cheaper than 12v 100 ah of calbs at 200 a pop.

 

[swbluto]

But again, bear in mind how many cycles you'd get from 12v 200 ah lead, if you only pull 100 ah per cycle from it. My off grid friend runs his entire household from 4 deep cycle lead batteries, that he just tops up daily when he runs a generator for about an hour. While the generator is on, he can run his fridge, AC, etc all at once. His lead is a lot cheaper than 12v 100 ah of calbs at 200 a pop.

I've been looking at lead. I project at my current usage rates, I'll need 5*150*12 = 9000 wh a day. So, I'd be looking at an 18,000 wh system for 50% DOD?

It seems like lead acid batteries traditionally come in at 1200 wh sizes (12v 100ah), so that's like 15x 12V 100Ah. About $2000.

I could probably reduce the size requirements by running the generator simultaneously. I do want to, however, maximize whatever energy I can capture from solar to minimize the ongoing gas costs. (Profit = revenue - expenses. The lower I can the monthly gas costs, the higher my profit margins. Not only is that important for becoming rich, it's also important just to survive the lean times!)

I can harvest about 5000wh per gallon of gas from a gen. So that 9000 wh is like 2 gallons of gas a day, nearly $100-$200/month.

My concern with batteries is that the climate I'm moving operations to is quite warm. Averages 50F in the depths of winter, 83F during the summer. That would probably reduce longevity. I wonder if moving the batteries underground (At least during the summer), similar to the concept of a wine cellar, would help extend battery life? Coincidentally, I do want to grow grapes so I can make wine, so a wine cellar might be on the to-do list anyway, lol.

 

[Icewrench]

Catch some of the waste heat from the generators exhaust. Turn it into hot water for heating or maybe steam for a sawmill. 8)

 

[dogman dan]

One solution would be using a lot less than 9000 wh per day. For sure my off grid buddy does not use nearly that much. His biggest use is running the fridge about 2-3 hours a day, and I think he never plugs that into his battery setup. That uses at best about a quart of gas per day. So his gas bill is way under $50 a month. The tv uses maybe 1000wh per day if on for hours. lights are led. His generator is the Honda 2000.

To be sure, he lives a very minimal lifestyle. Climate needs no AC. Most of the power he uses is propane stuff, heater, stove. He still works, or is gone fishing most of every day, so nothing is running while he's gone.

But AC, which will be your big drain, can run daytime when the panels are cranking, and perhaps be boosted by running the generator a few hours to top off some before night. More panels vs more battery? I don't know. I'm just saying you might be able to get by with a lot less battery than enough to pull 9000 wh out of them, with nothing feeding back in. Nothing wrong with a solar set up that fills by noon if you aren't drawing on it with the AC.

Re the AC, think in terms of cooling only the room you are using. I do that on my small ranch house. Window AC in each main room, only on when I'm in it. So the office AC runs all day, but nothing else in the house till past the peak of the heat. Then As evening cool comes, I cool the whole house down some, when the living room will be used.

 

[swbluto]

AC is for sissies. I plan on using water-cooling methods, largely because it's much cheaper to run. (I'm going to cool the water in the 'cooling reservoir' during the coldest part of the day, early morning, to attain that temperature, than try to maintain that temperature, or near it, throughout the day, either by using it to directly cool the air intake pipe or by gently spraying it on the operators face, lol. Seems like how cool ones face is the most important factor in the sensation of heat.)

I'm needing the energy for business, so it's a business expense (Still, I'd rather minimize that expense like anyone else, lol.). However, I will likely use a lot less than 18000 wh of batteries since that's capital I'd rather put to other uses.

 

[dogman dan]

True enough, running AC during the hottest part of the day is at least for dummies that did not insulate the house.

I saw a neat setup once here on a house. It solar heated in the winter, using a rock storage. In summer, he blew a swamp cooler through the rock from midnight to 6 am. Then the house stayed wonderful cool, without the humidity added by swamp coolers, all day.

I never could afford the rock storage on my house in the desert, but I did insulate. I am smart enough to turn on my AC when it's cool. then my whole house will keep it's cool till at least 3 pm, provided I'm not in that room breathing and heating it up, cooking, etc.

Call me a sissy for liking my house cool. But don't call me a sissy when I was young and on the job. No AC in any house I built, or any roof I worked on. I'm waaaay too familiar with a 120-140 degree work environment. After that shit,,, I still like a cool house.

Seems like if you are planning on no AC, you might not need 9000wh a day. My house runs the AC all summer, and in winter if the sun don't shine, my heat is electric. No gas in the house at all. So call me a watt hog house. My average is about 1kw a day.

 

[swbluto]

Seems like if you are planning on no AC, you might not need 9000wh a day. My house runs the AC all summer, and in winter if the sun don't shine, my heat is electric. No gas in the house at all. So call me a watt hog house. My average is about 1kw a day.

That's pretty impressive. I thought ACs were typically energy hogs during the summer. Maybe they're more of an energy hog in hot, humid climates (Like the southeast/gulf-states) that contain much more thermal energy and thermal conductivity than hot, dry climates(Like the southwest and west)?

Main reason I'm trying to avoid AC is because it's especially expensive for me. My rate is effectively 40 cents/kwh, compared to most people's 5-10cents/kwh.

 

[needWheels]

Good to see old nicknames around and kicking here. Just going to tail onto this thread instead of wasting a new one.

My 5/2009 Lau Chan Lifepo4.hk "clone ping pack" is still working believe it or not, but I only use it like once or twice a year at this point because I got a car and a regular road bike shortly after I built the ebike. I charge it like once a year to make sure the cells are balanced out.

Never did figure out if it was prismatic cells or 18650 cells.

I wonder how long it will work. I'm injured so can't use the regular bike, will see how far the ebike with this pack will take me.

Since it is 7 years old now, I am wondering if there is anything I should fear? I mean it is lifepo4 so it should be safer but I am ignorant as what to expect when it does fail someday. I expect a capacitor in the BMS would fail sooner than the pack?

 

[beast775]

needwheels, check voltage first,then do a full charge -check voltage...check voltage after 8 hrs sitting,go for a half hr run check voltage.let us know.

 

[needWheels]

needwheels, check voltage first,then do a full charge -check voltage...check voltage after 8 hrs sitting,go for a half hr run check voltage.let us know.

I forgot to check voltage first but I did a full charge 48 hours ago (it comes off the charger as 60.0v hot, but it always was like that)

Voltage now is 55.2 but I think I need to spray some contact cleaner on the plug because it's jumping with movement of the meter.

Will test a drive with it maybe Monday morning and report back.

 

[needWheels]

needwheels, check voltage first,then do a full charge -check voltage...check voltage after 8 hrs sitting,go for a half hr run check voltage.let us know.

oh wow - tried to do a 50 minute ride this morning of only 8 miles

drawing anything more than maybe 1C rate from it is now impossible, BMS immediately cuts out, hills are impossible

on the return 4 miles, if I tried to go any faster than 15mph or not assist pedal, even on flat ground it would cut out

last mile was completely human-powered, the "warning/dead" indicator on the throttle was lit and it's metered for SLA not lithium

so this huge $600 7-year old pack is basically a 30 pound doorstop now

of course this is with a huge brushed motor that when new it could climb literally any hill at 25mph without pedaling, so if I replaced it with a modern brushless I guess I could get a little more out of the pack but probably not another year

I think I have a few dozen cycles on this thing, definitely less than 100, probably less than 50

that was one expensive mistake, never again

 

[dogman dan]

Back to AC,, I don't cool a whole house. My whole house is small. So there is the savings. One small 8000 btu window unit might run more or less day and night, but the bulk of the house hits 80-85 F in the day. The other key thing is I have about R 35 in the attic. Ten years ago, I did use more power, before the trees on the west side of the house grew.

In the summer, I still have a huge AC bill. But it's not because I have a poorly insulated house that is kept 68f.

As for efficiency, AC works better if it's humid. In the hottest days, I go outside and hose down my window units mid afternoon, so they can blow cold again. The window units draw water out of the inside air, then the fan is designed to flick the water onto the coils outside. Whole house AC doesn't get that benefit.

I do have a swamp cooler on the roof, it runs only at dawn, to get the house cool for the day.

 

[needWheels]

aha! it's not my pack! it's just the charger!

holy cow, that test ride I did was with a nearly depleted battery, the 60v lifepo4 charger was not working after all these years, cannot believe how far I went with the pack being nearly dead

I noticed it was still only showing 53v after 12 hours of charging, when it should come off hot as near 60v

so I dug out my old SLA charger which only gets up to 55v but it was known working on this pack

and sure enough NOW the pack has full power, I can push the ebike as fast as I dare given its age and rubbing brakes

so now I need to find a cheap enough 60v replacement charger, any ebay suggestions?