Router Battery Backup

Received the Ratel 412p, this morning (Seems I got the last from Communica). POE to Mikrotik outside and powering Mi Router 3 inside, so 2 devices. Was 100% battery when I plugged it in. Left it unplugged for an hour, with both routers plugged in. Didn't budge from 100%.
 
akescpt said:
Only Vox customers? That’s a nice fit for purpose solution.
Click to expand...
Sorry, I don't know, I'm with them. So it was free delivery as well, and I figured if it didn't work to backup their own equipment I would get a refund.
 
I'm planning on going the Sherlo route to power my Asus router (it requires 19V). Can someone please recommend an excellent buck boost device? Please supply a URL. Alternatively, please point me to a decent store in the DBN area.

Thanks.
 
agentrfr said:
Lead batteries only like to get 50% DoD before you do damage to them (that is decrease their capacity)

Just go to communica and replace them with normal sealed 7Ah ones (~R150), then connect two 7Ah batteries in parallel. If they dont fit in the panel box then extend the connections and put the batteries on the floor.

Gel or not makes no difference because it's the heat in the roof/cupboard of the panel that kills the batteries over time. We only managed to get 6 months out of the batteries gel or not. Running two in parallel and they last 2 years or so, and as a bonus are perfectly happy for 10 hours runtime.

Heck if you are concerned, just wire three of them in parallel. Or use an old car battery - it wont be efficient to charge on the power supply but who cares if it takes 10 days to charge when it will last you just as long without power
Click to expand...

Actually I think one of the reasons these batteries tend to die faster is because they have less time to properly recharge.

I've had loadshedding in stage 2 where power goes off say 21:00-23:00 on day 1, then off again 3:00-5:00 day 2. That means that they don't have a lot of time to recharge probably between sessions (especially since I am running 2x 7Ah batteries in parallel on a charger designed for 1 7Ah battery). So the first loadshedding doesn't deplete the batteries, but the second session does.

And in the case of the sherlotronic psu kills the battery since it let it run to 10v. So the next session it has less capacity, reaches 10v faster and kills the battery even faster.

None of these 12v 7Ah lead cell systems were designed for regular power outrages!
 
So I ended up hacking together a quick battery monitor for my Sherlotronics PSU, now just runnning my Pi with Home Assistant.

1581445741096.png

It's a Wemos D1 with a voltage divider on the Analog-to-digital input (A0). The Wemos D1 runs off the 12v supplied by the Sherlotronics.

It runs ESPHome configured with the ADC sensor, MQTT and Deep Sleep. The latter was configured for 1 minute sleep, 10s awake to minimize it's impact on the Sherlotronics batteries. So I basically get a battery reading (between 0 and 15v) every minute, reported to Home Assistant running on the Pi.

I then get this (that was a 1.5 hour loadshedding session earlier tonight):

Screenshot 2020-02-11 at 20.31.42.png
and an automation which shuts down the Pi if the battery voltage goes beneath 12.1v:

Screenshot 2020-02-11 at 20.31.51.png

(The MQTT sensor is unavailable since the Wemos D1 is sleeping at the time).

Works great, haven't had the Sherlotronics run the batteries to <50% since I put this in place!
 
RichardZA7 said:
Hoping someone can shed some light, please:

Our alarm has two power packs (brand: Peak Power model TR6-HT_S042) each with an IDS 8Ah Gel battery in it, installed about 8 months ago. These are only used to power the external sensors (the rest is powered off the panel's own 8ah battery). Tonight they failed after 1 hour.

Instead of just replacing the batteries with the same I thought I should get bigger batteries but when I calculated the current draw to see what to get I do not understand how the current battery size isn't more than ample:

I traced which sensors are connected to which pack and looked up the manufacturer's (optex) spec for each one for current draw (@ 12VDC). I get to 58mA (1 x BX80 @ 38 mA + 1 x VXI-ST @ 20mA) on pack 1 and 77 mA (3 x VX + 1 x FIT-AT @ 17mA) on pack 2.

Since they were installed the longest outage I can remember (transformer fault) wasnt longer than 8 hours.

Even if you say 12 hours, there is no way that load would drain the batteries beyond 50% to damage them.

So now I'm stumped...

Before these packs were installed, all the external sensors were on a single pack (one of those Sherlo, assume 7Ah battery) which eventually couldn't handle the LS anymore and installer replaced with these two.

Anyone with experience with similar setup? Either the current draw actually much much higher than Optex says or these batteries or power packs are a load of rubbish.

I want to put in something that will actually last. Maybe I should switch to one of those Ratel 430m?

Thanks.
Click to expand...

Measured the actual current draw off each battery (with AC off, obv) as follows:

External sensors power packs EACH: 70mA

Panel's battery: 420 mA

Now what is really interesting and perplexing is that even though the panel draws 6 times as much current meaning its battery (which is identical to the external sensors packs - 8Ah Gel) is drawn down to far far lower DoD but it has never run out during load shedding/power outage, unlike the flaky power packs.

I can only conclude that these power packs somehow destroy the batteries during charging whereas the panel (Paradox SP6000) doesn't.

To me, replacing with bigger batteries/multiple in parallel at the power packs seems like a short term solution as I would expect the packs destroy those too.

I'm thinking I rather use a single Ratel 412 in place of the two packs - their combined current draw of 140mA @ 12V = 1.68W, so given the 412's rating of 15W for 4 hours should give me 35 hours. My only concerns/questions would be whether:

1) the low current draw will damage the liion batteries in long term?
2) if there is a momentary loss of power when it switches from mains to battery (that will cause the sensors zones to open and trigger alarm)?

Or any other thoughts on this?

Thanks
 
bobcpt said:
Would you mind sharing a pic of the splitter cable that gets included? My ONT device (Gigahub 812G) uses a 8 pin power connector, but it appears as if some of the newer ONT devices use a round connector.
Click to expand...
The splitter cable comes with a number of adaptors, all barrel connectors except one which looks a bit like a ps2 mouse connector, no 8 pin connector.
 
RichardZA7 said:
Measured the actual current draw off each battery (with AC off, obv) as follows:

External sensors power packs EACH: 70mA

Panel's battery: 420 mA

Now what is really interesting and perplexing is that even though the panel draws 6 times as much current meaning its battery (which is identical to the external sensors packs - 8Ah Gel) is drawn down to far far lower DoD but it has never run out during load shedding/power outage, unlike the flaky power packs.

I can only conclude that these power packs somehow destroy the batteries during charging whereas the panel (Paradox SP6000) doesn't.

To me, replacing with bigger batteries/multiple in parallel at the power packs seems like a short term solution as I would expect the packs destroy those too.

I'm thinking I rather use a single Ratel 412 in place of the two packs - their combined current draw of 140mA @ 12V = 1.68W, so given the 412's rating of 15W for 4 hours should give me 35 hours. My only concerns/questions would be whether:

1) the low current draw will damage the liion batteries in long term?
2) if there is a momentary loss of power when it switches from mains to battery (that will cause the sensors zones to open and trigger alarm)?

Or any other thoughts on this?

Thanks
Click to expand...
How many of the sensors do you have?
 
ebendl said:
Actually I think one of the reasons these batteries tend to die faster is because they have less time to properly recharge.

I've had loadshedding in stage 2 where power goes off say 21:00-23:00 on day 1, then off again 3:00-5:00 day 2. That means that they don't have a lot of time to recharge probably between sessions (especially since I am running 2x 7Ah batteries in parallel on a charger designed for 1 7Ah battery). So the first loadshedding doesn't deplete the batteries, but the second session does.

And in the case of the sherlotronic psu kills the battery since it let it run to 10v. So the next session it has less capacity, reaches 10v faster and kills the battery even faster.

None of these 12v 7Ah lead cell systems were designed for regular power outrages!
Click to expand...
Yes you are right

The charging circuit for 95% of panels assume Pb batteries. Remember that Pb batteries can only charge safely at 0.1C (i.e. a 7Ah battery at 0.7A) and as such the power supply itself is just a capacitive dropper circuit set to an ouput of ~13.8V @ ~1A (300mA for nomal panel operation)

Pb is only 60% couloumbic efficient, so it takes something like 20 hours to fully charge the battery from empty
 
agentrfr said:
Yes you are right

The charging circuit for 95% of panels assume Pb batteries. Remember that Pb batteries can only charge safely at 0.1C (i.e. a 7Ah battery at 0.7A) and as such the power supply itself is just a capacitive dropper circuit set to an ouput of ~13.8V @ ~1A (300mA for nomal panel operation)

Pb is only 60% couloumbic efficient, so it takes something like 20 hours to fully charge the battery from empty
Click to expand...

Thanks for the detailed information -- glad my assumptions were correct.

The voltage across the battery when the Sherlotronics is charging starts off at 13.25 V and seems to be trending upwards over time as the battery gets charged (I assume). Now up to an average of about 13.4 V around 18 hours later:

Screenshot 2020-02-12 at 12.13.04.png
 
Speedster said:
Each with their own power pack, or do they share. If they share then surely your usage should be 70mA x 6 = 420mA?
Click to expand...

They're split across two power packs. The 70mA is what actual current draw I measured from each power pack's battery, which roughly matches sum of the manufacturer's rated consumption of each sensor. So total draw of all 6 sensors is 140mA (@ 12V)

I've ordered a 412 today that I'll connect all 6 sensors to instead of the two power packs as they have killed my batteries (per earlier post) despite it being impossible at that current draw for the batteries to have been drawn below 50% DoD (they're 8Ah Gel, about 8 months old).

Based on the 412 having 8800mAh @ 3.7 that and assuming 90% efficiency gives 2442mAh @ 12V (if my math is correct) which at 100% DoD will run the sensors for 17 hours. Will post feedback.

Probably going to order 430 or 860 for router and fibre once they in stock.
 
ripclaw said:
I'm planning on going the Sherlo route to power my Asus router (it requires 19V). Can someone please recommend an excellent buck boost device? Please supply a URL. Alternatively, please point me to a decent store in the DBN area.

Thanks.
Click to expand...

Amazon.com: KNACRO Waterproof DC/DC 12V Step Up to 19V 3A 57W Voltage Boost Converter Regulator Transformer Power Supply for Car Truck Vehicle: Home Audio & Theater

Amazon.com: KNACRO Waterproof DC/DC 12V Step Up to 19V 3A 57W Voltage Boost Converter Regulator Transformer Power Supply for Car Truck Vehicle: Home Audio & Theater
www.amazon.com

Bought something similar from amazon.
 
You must log in or register to reply here.
Back
Top
Sign up to the MyBroadband newsletter
X