I have 1 kW Mecer trolley inverter with a 100 Ah battery. I bought the device 5 months ago and so far it has done an outstanding job powering my home office and TV during loadshedding. Lately it lasts only 60 minutes when I’m lucky. The drop-off has been dramatic and my loads have not increased. I know these lead acid batteries don’t last long, but surely it cannot be this short. Any advice? Or is it just a case of returning it to the supplier as it is still under warranty. 

1 hour ago, johanduplessis1995 said:

Or is it just a case of returning it to the supplier as it is still under warranty

Return it if it's still under warranty. Trust that the battery is under warranty too,
 

1 hour ago, johanduplessis1995 said:

I know these lead acid batteries don’t last long, but surely it cannot be this short

It could be that short if you regularly drained your battery below 50%. The cycle life of LA batteries reduces at exponential rates once you go below 50% regularly, which I suspect was probably the case with all the loadshedding and not enough time between loadshedding to get the battery fully charged again.

Thanks for the advice. 
I’ve checked the voltage and it is 12.93 V which should be good enough, why won’t the invertor run? Perhaps checking the voltage is not a good enough test to see if the battery is dead. 

On 2022/12/08 at 9:03 PM, johanduplessis1995 said:

I have 1 kW Mecer trolley inverter with a 100 Ah battery. I bought the device 5 months ago and so far it has done an outstanding job powering my home office and TV during loadshedding. Lately it lasts only 60 minutes when I’m lucky. The drop-off has been dramatic and my loads have not increased. I know these lead acid batteries don’t last long, but surely it cannot be this short. Any advice? Or is it just a case of returning it to the supplier as it is still under warranty. 

60 minutes - seems normal for a 5 month old lead battery subject to current levels of load shedding and below 50% DoD.
Seems you getting the expected life out of a lead battery based system.

Did you change parameter 19 on your inverter to prevent over 50% DoD?

For current levels of load shedding, lead batteries are not recommended.
Lead batteries have a cycle life of approximately 300-600 cycles with 50% Depth of Discharge (DoD) - much less if you exceed 50%.
After ~66 days of load shedding 3 time/day, your typical lead-acid battery will loose ~50% of its capacity if run flat during those 2 - 3 hours.
Only viable option for daily use is Lithium based batteries, depending on composition, Lithium batteries have 3000-6000+ full cycles with 95% DoD & 80% capacity at the end.

Also lead batteries are only 50% efficient and Lithium are +90% efficient.

Edited December 11, 20223 yr by system32

1 hour ago, johanduplessis1995 said:

Thanks for the advice. 
I’ve checked the voltage and it is 12.93 V which should be good enough, why won’t the invertor run? Perhaps checking the voltage is not a good enough test to see if the battery is dead. 

If this voltage is above 12V at least with very low load it should start. As a test just disconnect the normal battery and with the inverter off connect on the car battery with jumpers with a once positive connection to contain sparking and try again. Then you can confirm it's not the battery if it switches on. 

Bear in mind these are sold with start cycle batteries. Warranty not in place if you cycle them on an inverter. The depth of discharge can be checked when you submit a claim. 

13 minutes ago, Scorp007 said:As a test just disconnect the normal battery and with the inverter off connect on the car battery with jumpers with a once positive connection to contain sparking and try again. Then you can confirm it's not the battery if it switches on. 

Excuse my ignorance, but what do you mena with a “once positive connection”? 
 

1 hour ago, johanduplessis1995 said:

Excuse my ignorance, but what do you mena with a “once positive connection”? 
 

Don't let the jumper wire make and break and make and break that causes sparking each time it makes contact. 

On 2022/12/08 at 9:03 PM, johanduplessis1995 said:

I have 1 kW Mecer trolley inverter with a 100 Ah battery. I bought the device 5 months ago and so far it has done an outstanding job powering my home office and TV during loadshedding. Lately it lasts only 60 minutes when I’m lucky. The drop-off has been dramatic and my loads have not increased. I know these lead acid batteries don’t last long, but surely it cannot be this short. Any advice? Or is it just a case of returning it to the supplier as it is still under warranty. 

Is it possible that at current load shedding levels, it is not getting time to recharge fully between sheds?

Looking at where I live, the last week or so we have often had 11 hours out in a day. This scenario can happen: loadshed from 8:00 to 12:30. Then another from 16:00. If your system can't fully recharge in 3.5 hours, you're going to run into trouble. 

 

18 hours ago, system32 said:

For current levels of load shedding, lead batteries are not recommended.
Lead batteries have a cycle life of approximately 300-600 cycles with 50% Depth of Discharge (DoD) - much less if you exceed 50%.

I don't disagree with any of the above, but I have many neighbours who would like to go for lithium batteries, even a full PV system, but whose finances constrain what they can do.

Part of the problem with these inverter/SLA systems is that there are batteries and there are batteries and not all batteries are equal. If you buy the inverter from a chain store and then pop into your nearest battery fitment center you are going to get one thing, if you go to a business that specialises in UPS systems you may find you get something better suited to the job.

My mother has an inverter that we bought from Maiden Electronics in Kyalami. During the last 6 months of load shedding it has let her down only once, and that was when a substation went pop and they were without power for 18 hours. I thought "well, that's that for those batteries then" but didn't say anything more than "we'll keep an eye on those batteries for a while". But as far as I can see they recharged once the power came back on, and have kept going since then. Admittedly with a light load - DSTV, smart TV (about 40 odd CM) and charging phones.

I had a neighbour who used to complain about his inverter would barely last an hour, again just backing up TV, decoder and a couple of lamps. I asked him where he got the batteries, it was from some guy down at the mall. I told him to contact Maiden post haste. A couple of days later he was smiling. He has since moved away, but last time I saw him those batteries were a year old and still keeping him happy (judging by the extension leads running all over his home, he'd upped the load a bit).

I don't want to keep on punting one company, but my point is that those guys are specialists in that field. That is all they do, and they have been doing it for years now. So they know their stuff. So when you have to change batteries, be it sooner or later, speak to a specialist.

2 hours ago, Bobster. said:

I don't disagree with any of the above, but I have many neighbours who would like to go for lithium batteries, even a full PV system, but whose finances constrain what they can do.

Part of the problem with these inverter/SLA systems is that there are batteries and there are batteries and not all batteries are equal. If you buy the inverter from a chain store and then pop into your nearest battery fitment center you are going to get one thing, if you go to a business that specialises in UPS systems you may find you get something better suited to the job.

My mother has an inverter that we bought from Maiden Electronics in Kyalami. During the last 6 months of load shedding it has let her down only once, and that was when a substation went pop and they were without power for 18 hours. I thought "well, that's that for those batteries then" but didn't say anything more than "we'll keep an eye on those batteries for a while". But as far as I can see they recharged once the power came back on, and have kept going since then. Admittedly with a light load - DSTV, smart TV (about 40 odd CM) and charging phones.

I had a neighbour who used to complain about his inverter would barely last an hour, again just backing up TV, decoder and a couple of lamps. I asked him where he got the batteries, it was from some guy down at the mall. I told him to contact Maiden post haste. A couple of days later he was smiling. He has since moved away, but last time I saw him those batteries were a year old and still keeping him happy (judging by the extension leads running all over his home, he'd upped the load a bit).

I don't want to keep on punting one company, but my point is that those guys are specialists in that field. That is all they do, and they have been doing it for years now. So they know their stuff. So when you have to change batteries, be it sooner or later, speak to a specialist.

A friend is Work-From-Home and his company supplied thousands of staff with these "trolly" UPS with 100Ah AGM battery.
100Ah * 12V ~ 1200Wh, at 50% DoD ~ 600Wh usable.
The typical load is ~100-150W consisting of laptop/pc, special vpn router, wifi, ont, 21" screen.
After 26 months most have had their batteries replaced once and are again unable to sustain the load for two hours.
They seem to have exceeded the number of cycles 300-600 of AGM batteries or are damaged due to being discharged below 50% DoD caused by longer outages and misconfigured shutdown settings on the inverter and not enough time between load shedding to recharge.

They now considering a lithium battery based solution.

 

 

Edited December 12, 20223 yr by system32

2 hours ago, system32 said:

A friend is Work-From-Home and his company supplied thousands of staff with these "trolly" UPS with 100Ah AGM battery.

No wonder the shops are short stocked!

Thanks for the input everyone. Long story short: I’m ordering a lithium ion battery. If that doesn’t work, I’m buying a one-way ticket to Australia. 

It is really sad to see how few people just install a loose R100 voltmeter and switch the inverter of when it reaches 11.8V per battery under load when using lead acids. One just need to have a quick look now and again and will get a early warning for a battery that is also loosing capacity. One can then plan the replacement long before it dies within say 30min from the onset of LS. 

Update

I noticed something strange. When I have loads connected to the inverter and loadshedding kicks in it shuts down instantly. Almost like it cannot handle that sudden switch. When I remove the loads, turn off the mains and then apply the same loads incrementally, then it handles it with a smile. 

I wonder the problem is not related to another component and not the battery. 

13 hours ago, Scorp007 said:

It is really sad to see how few people just install a loose R100 voltmeter and switch the inverter of when it reaches 11.8V per battery under load when using lead acids. One just need to have a quick look now and again and will get a early warning for a battery that is also loosing capacity. One can then plan the replacement long before it dies within say 30min from the onset of LS. 

Can you expand on this a little please. I have a R100 multimeter, but I seldom use it for anything bar checking continuity. What should one be monitoring, and what are the signs that a replacement is needed?

16 hours ago, johanduplessis1995 said:

If that doesn’t work, I’m buying a one-way ticket to Australia.

I have bad news for you there, boet, according to my mate, Ian, who's near Melbourne, in Kyneton, their power grid is also becoming flakey due, in part, to the "Greenification" of the grid over there... so fleeing down under, may not be the best option...

4 hours ago, Kalahari Meerkat said:

I have bad news for you there, boet, according to my mate, Ian, who's near Melbourne, in Kyneton, their power grid is also becoming flakey due, in part, to the "Greenification" of the grid over there... so fleeing down under, may not be the best option...

South Australia grid is 'collapsing' because Scott Morrison ate the big banana in South Australia.

 

Edited December 13, 20223 yr by system32

On 2022/12/12 at 6:16 PM, johanduplessis1995 said:

Update

I noticed something strange. When I have loads connected to the inverter and loadshedding kicks in it shuts down instantly. Almost like it cannot handle that sudden switch. When I remove the loads, turn off the mains and then apply the same loads incrementally, then it handles it with a smile. 

I wonder the problem is not related to another component and not the battery. 

It depends on the surge ability of the inverter. Something like a fridge, freezer, air con will impose huge surge currents.

5 hours ago, Tinbum said:

It depends on the surge ability of the inverter. Something like a fridge, freezer, air con will impose huge surge currents.

Together with this it could also be the ability of the battery to supply the surge current which affects the inverter to start these devices. 

@Bobster.

With the meter on the right DC voltage scale just have red on the one pole of the battery and the other lead on the other pole and get the reading. The problem with the multimeter and more so the better ones is that it will switch of after a while. The small digital meter will stay on and give a reading all the time. The meter in the picture can normally read from above 4V when self powered up to 30V for the one model and up to 100V for the higher voltage model. 

Using it this way one will also see how low the battery drops when starting a device like fridge, aircon that has a very high surge current. 

Edited December 14, 20223 yr by Scorp007

When replacing these batteries look at getting a bigger capacity battery or double up batteries in parallel to get more capacity.

Going to lithium is the better option but its a bigger cost outlay so look at the budget and what you want to achieve.

The inverter trolleys are great but most poeple seem to grow out of what it can do rather than buy a bigger unit than what they need.

As much as more capacity helps it is the discharge level that must be managed. More capacity and use more is the downward spiral. 

An example. I installed a brick type 1500W pure sine in an auditor's office 2 years ago. Small voltmeter to ensure battery never goes below 11.8V. Small intelligent 4A charger. My wife manages the discharge. At times of little LS my brief is to discharge the 100Ah battery once a month by connecting the desktop up to 11.8V discharged. Battery is still fine for the low load of the office. 

Battery Centre silver calsium battery. Not even a Gel or AGM. 

I bought a led-acid battery ups system which I was told needed at least 12 hours of charging between load shedding sessions so alternated between a lithium battery 

portable system and the main system. But despite complying with the 12 hour (which I often stretched to 24 hours and sometimes 36 hours) to make sure my led battery didn't run down to 50% and less, and only running an i-pad from it (not a computer) the system wasn't able to hold up to even an hour of load-shedding. I am now in the process of waiting for a refund from the supplier, who offered it with a 10% handling fee, and sincerely hope they will uphold their offer otherwise I will hand the matter over, as I feel the supplier needs to take responsibility for offering an inadequate system.