[Thad E Ginathom]

Su-kam Solar UPS 1 KVA Rs.18,500.00

SU-KAM Solar panel 4*250 Rs.64,000.00

SU-KAM Tall tubular Battery 150ah 1 Rs.14,500.00

Panel angle Rs.10,000.00

Installation extra.

e&oe in my copying!

Except I think there should be two batteries, which would increase the total from 1,07,000 to 1,21,500

[deep_bang]

Originally Posted by Holyghost

My 3kw SuKam grid tie setup costed a little over 2Lakhs. 1L+ for a 1kva battery based system seems too high. Please check the cost of having a 1kw grid tie + a normal inverter.

How is it working out till now? I was considering this for almost 2 years but worried about the bureaucratic processes I may have to go through with BESCOM to get paid for the electricity given back. A friend I know has this and not yet got paid by BESCOM even after a few months of this system beig installed. Hence the question.

[hserus]

Originally Posted by deep_bang

How is it working out till now? I was considering this for almost 2 years but worried about the bureaucratic processes I may have to go through with BESCOM to get paid for the electricity given back. A friend I know has this and not yet got paid by BESCOM even after a few months of this system beig installed. Hence the question.

For most if not all intents and purposes a regular inverter that runs off batteries is just what the doctor ordered.

There is a govt subsidy on solar panels but ridiculously difficult to claim back, much the same trouble as trying to get credit for electricity that you feed back into the grid.

[Thad E Ginathom]

Thinking about the above mentioned 1kva system with 1k panels, I don't think it is a good buy for me.

The Sukam Brainy system, with 500w panels still adds up to 60K. It would keep my computer and more than enough lights/fans going. The higher price system would add a small fridge, but not an AC unit. So it is no-man's land. The real next step for me would have to be something like 5kva to power an AC machine, and the cost increment is obvious and impossible.

Advantages of the 1-lakh-plus system would probably be that, on 10%-power days, 10% of 1Kw would a usable hundred watts, instead of 10% of 500W being a one-light-bulb 5W. If it works like that.

I also suspect that the PCU/inverter is much more industrial-build (at twice the price) than the Brainy, which adds solar at not much more than the cost of an ordinary domestic inverter. Clarification is that it is a PWM model, the MPPT model being a whole 5K more expensive.

I would end up with a solar inverter, two 150amp-hour batterries (keeping my existing fairly young tall tubular) (in 12v-parallel for the brainy) and two 250w pv panels for 60K plus installation.

I think the panels are the same, so upgrade is perfectly possible.

[Holyghost]

Originally Posted by deep_bang

How is it working out till now? I was considering this for almost 2 years but worried about the bureaucratic processes I may have to go through with BESCOM to get paid for the electricity given back. A friend I know has this and not yet got paid by BESCOM even after a few months of this system beig installed. Hence the question.

My system is installed in Trivandrum, Kerala. It took 7 months to get all the approvals to connect the system to the grid. In Kerala, the payment is settled once in a year. I think it is every September. I dont expect any payment from the Govt and I am not ready to run pillar to post for their payments. My target is to offset my consumption.

I am also looking at the new 4 door Mahindra e2o in which case I might add another 2-3kw panels in future. The grid tie systems are easily scalable and you can add more grid-tie inverters in series to expand your capacity in future.

[Prowler]

I have an odd problem with our Online 3 KVA UPS. It originally had 4 x 85 AH batteries and we kept replacing them as they aged. We used normal CRT monitors when we bought the UPS ages ago. Now we have LED monitors and the computers came down in numbers.
When the last batch of 85 AH batteries were in service we used to have 8 hours of backup with our server + peripherals. I replaced the set with 35 AH batteries to keep the costs low. My logic was we would have a backup time of at least 3 hours under the same condition.
But we now have only about 30 -45 minutes of backup time. The batteries are new and there is no other malfunction in the UPS. Why did the backup time fall so drastically ?
Digging with the VOM, i found that from a fully charged condition of 54.4 V it drops rapidly to 46 V when it starts beeping and within a short time it comes down to 45 whereupon the UPS trips.
What do I miss ? I would be grateful for any pointers.

[Aroy]

Originally Posted by Prowler

I have an odd problem with our Online 3 KVA UPS. It originally had 4 x 85 AH batteries and we kept replacing them as they aged. We used normal CRT monitors when we bought the UPS ages ago. Now we have LED monitors and the computers came down in numbers.
When the last batch of 85 AH batteries were in service we used to have 8 hours of backup with our server + peripherals. I replaced the set with 35 AH batteries to keep the costs low. My logic was we would have a backup time of at least 3 hours under the same condition.
But we now have only about 30 -45 minutes of backup time. The batteries are new and there is no other malfunction in the UPS. Why did the backup time fall so drastically ?
Digging with the VOM, i found that from a fully charged condition of 54.4 V it drops rapidly to 46 V when it starts beeping and within a short time it comes down to 45 whereupon the UPS trips.
What do I miss ? I would be grateful for any pointers.

The AH ratings are for 10 hour discharge, so with 85AH batteries you should get 8.5A for 10 hours. The catch is that as the discharge increases the capacity rating decreases. The exact figures are available in some battery sites, but as far as I can recollect doubling the discharge rate reduces the backup time by four times (not two times).

Another factor is the charging current. For 85AH a higher current is used compared to 35AH. That would have a major impact on capacity, unless the charging circuit takes lower capacity into account.

In your case I would recommend that you estimate the current load and them change your UPS to match the load.

Here are a few links that would help you
http://pvcdrom.pveducation.org/BATTERY/charlead.htm
http://www.power-sonic.com/images/po...hManual-Lo.pdf
http://homepages.which.net/~paul.hil...eriesBody.html

[Prowler]

Originally Posted by Aroy

The AH ratings are for 10 hour discharge, so with 85AH batteries you should get 8.5A for 10 hours. The catch is that as the discharge increases the capacity rating decreases. The exact figures are available in some battery sites, but as far as I can recollect doubling the discharge rate reduces the backup time by four times (not two times).

Thank you so much Aroy Sir. So in my case the battery capacity has come down drastically as the UPS draws about 8 A under the normal load which is way above its C rate of 3.5 A

Would it be a good idea if I buy another set of 35 AH batteries (same Amaron and same type) and connect them in parallel ? That way I would have 70 AH capacity in theory. Problem would be as the current set of batteries age, they would skew the charging current.

[Aroy]

Originally Posted by Prowler

Thank you so much Aroy Sir. So in my case the battery capacity has come down drastically as the UPS draws about 8 A under the normal load which is way above its C rate of 3.5 A

Would it be a good idea if I buy another set of 35 AH batteries (same Amaron and same type) and connect them in parallel ? That way I would have 70 AH capacity in theory. Problem would be as the current set of batteries age, they would skew the charging current.

That would help. I would not parallel old and new batteries, rather pair off the old batteries and new batteries (if you have even numbers). Just read up about how to prevent overcharging in one battery when two or more are connected in parallel.

[Prowler]

Originally Posted by Aroy

That would help. I would not parallel old and new batteries, rather pair off the old batteries and new batteries (if you have even numbers).

Thanks again Aroy Sir. I will report back after I hook them up. Hope it increases the backup time to 'normal' level.

[Aroy]

Originally Posted by Prowler

Thanks again Aroy Sir. I will report back after I hook them up. Hope it increases the backup time to 'normal' level.

If you can get hold of a DC Ammeter, then use it to check the current consumed while the UPS is on. That will give you a clue to whether it is the batteries or an aging UPS that is the culprit.

[diyguy]

Originally Posted by Thad E Ginathom

Thinking about the above mentioned 1kva system with 1k panel.

saw this ad in the paper today at your favorite weekend hangout

[Thad E Ginathom]

Originally Posted by diyguy

saw this ad in the paper today at your favorite weekend hangout

Oh, thank you! I didn't know about this one at all.

Tomorrow... If I can...

[diyguy]

I may have an issue with my amaron battery. I had filled it about 5 months back but the water does not seem to reduce in it at all. On the other hand I have an exide which needed a refill last week. Both are tall tubular and the amaron is newer. I switched my inverters with the batteries and notice that the inverter connected to the amaron is always in charge mode and seems to be running hot always. The other inverter connected to the exide is never hot except probably when it is providing backup during a power cut. Could this indicate that the amaron has an issue? It does work during a power cut but just wondering if the continuous charge indication is due to a battery failure or cell failure within.

[bluevolt]

Can tractor batteries be used in invertors? (90 ah/600VA)