Suggest UPS that can handle 800-900w load

variablevector · Oct 23, 2024

n1r0 said:
The only thing inferior about them is the smaller capacity since they are physically smaller.

Sealed Lead Acid battery aka AGM VRLA (Absorbent Glass Mat Valve Regulated Lead Acid) are sealed and require no maintenance.

The electrolyte in flooded batteries doesn't dry up due to evaporation, but electrolysis where water (H20) splits into Hydrogen and Oxygen gas and escape.

Since AGM VRLAs are sealed, the gases are trapped inside the battery and recombine back to form water, therby restoring the original electrolyte level.

Since they are sealed, there's no risk of leakage even if the battery is installed on its side, upside down etc..

AGM batteries do lose their electrolyte level over time. And there are people who repair them by opening them up and adding distilled water back into the fiberglass mat.

I actually can't find any hard data regarding deep-cycle AGM lifespans vs deep-cycle flooded lead acid. Especially the Tubular type of flooded lead acid that gets commonly used in inverter systems. But there is this comparison table that indicates they're similar. Either way flooded lead acids are cheaper and much more widely available here.

n1r0 said:
Best option would be to keep the PC UPS and hook it up to a Home Inverter. This way you don't need to hunt for a HI with fast switchover UPS mode, which may consume more current.

OP's UPS doesn't work anymore, otherwise that would indeed be a good option.

rsaeon said:
If you're looking try out a pre-built lifepo4 pack or build one yourself, myinnovation.in currently has a flat 10% sale.

For bare 32700 cells, this brings the price down to Rs 185 for a 3C rated cell inclusive of taxes and shipping.

I purchased 120 of these from them during their previous sale last month for an upcoming project and they arrived within a couple of weeks. Packaging was decent and a few randomly chosen cells tested okay.

The founder/owner appears to be humble and hardworking, he posts behind-the-scenes shorts and videos on their YouTube channel. In one of them, while he's trying to show the legimacy of his enterprise because of the criticism they receive for not having a cash on delivery option, he inadvertently shows their total lifetime revenue — over 5 crores!

I paid the advance on 8 x 280Ah Hithium cells from the MDS enterprises guy but a few days before he was going to ship them, all the Manipur stuff happened and he had to refund me and close his store temporarily. I got very unlucky there, lol.

rsaeon · Oct 23, 2024

variablevector said:
I paid the advance on 8 x 280Ah Hithium cells from the MDS enterprises guy but a few days before he was going to ship them, all the Manipur stuff happened and he had to refund me and close his store temporarily. I got very unlucky there, lol.

Wow. I had wondered what happened to them, I wanted to buy from them but I didn't get any reply or call backs so I went with 32700's from myinnovation.in instead.

variablevector · Oct 23, 2024

rsaeon said:
Wow. I had wondered what happened to them, I wanted to buy from them but I didn't get any reply or call backs so I went with 32700's from myinnovation.in instead.

Yeah, he really was one of the few good sources and I think he plans to reopen. But last I checked, the national highways were blockaded. Not sure if that has changed since then. Any up-to-date news from Manipur seems sparse.

n1r0 · Oct 23, 2024

variablevector said:
AGM batteries do lose their electrolyte level over time. And there are people who repair them by opening them up and adding distilled water back into the fiberglass mat.

There's a difference between designed to require regular top-ups vs topping up in case of defects or to refurbish when the seal breaks and water escapes.

Also, you're confusing flooded vs tubular

In 12+ years not once did I have to top up my bikes' VRLA batteries. Car on the other hand gets topped up at the yearly service; even though it's SLA

variablevector said:
comparison table

What does that table say regarding VRLA maintenance?

variablevector said:
OP's UPS doesn't work anymore, otherwise that would indeed be a good option.

OOPS I totally missed that, my bad!

variablevector · Oct 23, 2024

n1r0 said:
There's a difference between designed to require regular top-ups vs topping up in case of defects or to refurbish when the seal breaks and water escapes.

I mean, I'm not saying flooded doesn't require maintenance. I'm saying AGM does lose electrolyte at some point, clearly. Not sure if all of them fail the same way, but certainly enough of them do to warrant this being a common repair method.

I have an Amaron bike battery, manufactured in Jan 2023, that was not putting out enough amps to start my Vitpilen 250. One of these days, I might look into opening it up and seeing if the fiberglass mat is dry inside it. It sounds like it is.

As for the inconvenience of maintaining flooded, they need to be refilled like twice a year or so, in my experience. Even if it was twice that -- It's hardly a problem for an inverter battery.

In a car/bike, it's adding another thing to maintain and that can go wrong. As well as needing to be oriented right, space constraints etc. So it makes sense why VRLA gets used there.

Can you find a battery for OP in the 150-200Ah range that is VRLA and competitively priced?

n1r0 · Oct 23, 2024

variablevector said:
I mean, I'm not saying flooded doesn't require maintenance. I'm saying AGM does lose electrolyte at some point, clearly. Not sure if all of them fail the same way, but certainly enough of them do to warrant this being a common repair method.

If a person losses blood, a transfusion is needed. That does not imply everyone needs a transfusion at some point in their life. Only if there is blood loss due to injury or something do you need to think about transfusion. You're confusing exceptions with the norm.

variablevector said:
I have an Amaron bike battery, manufactured in Jan 2023, that was not putting out enough amps to start my Vitpilen 250. One of these days, I might look into opening it up and seeing if the fiberglass mat is dry inside it. It sounds like it is.

Unless you ride the bike regularly on highway, it sounds like a defective battery. Mine will be 5 years old in March (I think) and still cranking well. So your logic of every battery needs top up is flawed. Repair != Maintenance

variablevector said:
Can you find a battery for OP in the 150-200Ah range that is VRLA and competitively priced?

No, VRLA by design is "better", so more expensive. If it were cheaper, everyone would already be using it. This is the reason inverters use flooded tubulars.

variablevector · Oct 23, 2024

n1r0 said:
If a person losses blood, a transfusion is needed. That does not imply everyone needs a transfusion at some point in their life. Only if there is blood loss due to injury or something do you need to think about transfusion. You're confusing exceptions with the norm.

Ah I see! Your argument hinges on the frequency with which VRLAs fail due to dried up electrolyte i.e their most common failure mode. This is good because it can be proven empirically.

Here's a direct quote from a paper I found:

Valve-regulated lead-acid (VRLA) batteries, which require no water maintenance, have increasingly replaced conventional flooded batteries in stationary applications, e.g., in telecommuni- cations and uninterruptible power-supply systems. Nevertheless, it has been found [1–4] that the endurance of VRLA batteries under such applications can be much shorter than the design life, which is typically 20 years. The main failure modes of these batteries are as follows: dry-out and thermal runaway, selective discharge of neg- ative or positive plates, heavy grid corrosion, and positive-plate failure (Fig. 1). While there are several possible causes for a given failure mode, it is clear that residual elements can exert a strong influence on all failure modes through gassing effects. Thus, obviously, controlling of the influence of residual elements on gassing rates to within the safe limits is a key strategy for improving the life of VRLA batteries

Ref. There you go. Contradicted by no less than Australia's national science agency. That's as definitive as we're going to get without running some studies ourselves.

n1r0 said:
Unless you ride the bike regularly on highway, it sounds like a defective battery. Mine will be 5 years old in March (I think) and still cranking well. So your logic of every battery needs top up is flawed. Repair != Maintenance

That's not my actual position. My position is that VRLAs need zero maintenance compared to FLAs. But when they fail, they fail frequently due to a lack of electrolyte, which is interesting because FLAs are designed to have their electrolyte replenished with minimal effort on the end user's part. This causes me to prefer them, unless I see some strong evidence that VRLA's still have better lifespans than an equivalent FLA.

msvsme · Oct 23, 2024

variablevector said:
Yeah, he really was one of the few good sources and I think he plans to reopen. But last I checked, the national highways were blockaded. Not sure if that has changed since then. Any up-to-date news from Manipur seems sparse.

Highways are open. But could close anytime if skirmish happens. Everything in Manipur is bad to run a business. I feel bad for him.

I think lifepo4 cells have come down in price. YT sellers Vippotech and technical power sell 3.2v 100ah lifepo4 for Rs.2000-2500. I was planning to buy from the yt sellers instead for my 8s 100ah inverter pack in the future. I bought 4 6A cells from vippotech. Not sure about technical power.

variablevector · Oct 23, 2024

msvsme said:
Highways are open. But could close anytime if skirmish happens. Everything in Manipur is bad to run a business. I feel bad for him.

I think lifepo4 cells have come down in price. YT sellers Vippotech and technical power sell 3.2v 100ah lifepo4 for Rs.2000-2500. I was planning to buy from the yt sellers instead for my 8s 100ah inverter pack in the future. I bought 4 6A cells from vippotech. Not sure about technical power.

I feel like 2.5k is a great price for a new cell. And even if it doesn't last for as many cycles as you'd like because it is a lower grade, you're still doing way better than lead acid!

msvsme · Oct 23, 2024

True. Lead acid is very bad for heavy load in my case. I have 2 12v 150ah lead acid battery in series. Both are c20.
So, battery is 3.6kw in capacity. But running a 1000w heater, my inverter hits battery low very fast, maybe after half and hour. although i keep my low cut off higher than factory for longevity.

But running it at low power draw is fine. I draw 1.5kw to 2kw every night from it running leds and pc.

And my solar panel is 1150w. But charger set to 17a which is around 400w charge. So, unless I add another two battery on series, it's not going to charge fast. And if I charge faster battery will go spoilt.

Lifepo4 is the way to go! Just sharing my experience.

rsaeon · Oct 23, 2024

msvsme said:
True. Lead acid is very bad for heavy load in my case. I have 2 12v 150ah lead acid battery in series. Both are c20.
So, battery is 3.6kw in capacity. But running a 1000w heater, my inverter hits battery low very fast, maybe after half and hour. although i keep my low cut off higher than factory for longevity.

But running it at low power draw is fine. I draw 1.5kw to 2kw every night from it running leds and pc.

That would be Peukert's Law in effect: https://en.m.wikipedia.org/wiki/Peukert's_law

The more power you draw from a lead acid battery, the lower usable capacity it has.

msvsme said:
And my solar panel is 1150w. But charger set to 17a which is around 400w charge. So, unless I add another two battery on series, it's not going to charge fast. And if I charge faster battery will go spoilt.

Yep, and that's why there's an entire industry for optimally sizing solar powered setups. Charging at C20 for 100Ah battery means a 5A charge current, but usuable sunlight is only around 5 hours a day.

In an ideal solar setup, the batteries never go below 20% depth of discharge, so you're only topping up the 20% you used in the last 19 hours with those 5 hours of sunlight.

It's fascinatingly expensive to do it properly.