Low Battery Notification Gremlin

[mtmcgavock]

Got a HR92 that's reporting a low battery.

In my annual get ready for Winter jobs, i've swapped out all the batteries in the HR92s for new Lithium AAs. The HR92 in question wasn't reporting a low battery beforehand.

After changing the battery setting to Lithium and swapping the batteries I keep getting a low battery notification, even though the HR92 shows a 3 bars on the battery. Tried tensioning the connectors etc.

Any ideas?

[BuxtonJim]

Sorry I can't help directly but I'm having an analogous issue. My kit has been fully installed for 23 months and the original batteries are now starting to fall over like dominoes. I guess I may have been lucky with the original batch but it was beyond my planned expectation so I laid in alkaline replacements in expectation of an 18 month life cycle. As I replace the original batteries the replacements are mainly showing only 2 bars and the Evotouch is reporting periodic alerts. Those displays are only indicative I know and maybe capacity has dropped in the meantime.

As a result, I'm now following Paul Lockenden's advice and installing lithium Energizers simply to move on.

Every situation has different characteristic and usage of course but without stable local batteries my whole system has started falling over.

[DBMandrake]

Got a HR92 that's reporting a low battery.

In my annual get ready for Winter jobs, i've swapped out all the batteries in the HR92s for new Lithium AAs. The HR92 in question wasn't reporting a low battery beforehand.

After changing the battery setting to Lithium and swapping the batteries I keep getting a low battery notification, even though the HR92 shows a 3 bars on the battery. Tried tensioning the connectors etc.

Any ideas?

Even though you tried retensioning the contacts it's still probably a high resistance connection. When there is no load the voltage will be high and therefore the battery reading (which doesn't update very often) will be OK, but when the motor tries to turn especially against the limit stops it will cause a voltage drop large enough to send a low battery alert.

What happens if you hold the HR92 (removed) upright in one hand and thump it down hard into your other hand to give it a good shock ? Does it reboot when you do that ? If so you have more work to do on the battery contacts...

While it's usually the ones at the bottom that are the problem as the weight of the batteries squashes them down over time, I have also had problems with the shorting bar at the top on a couple of mine - it's soft as butter and bends easily, if it bends the "wrong" way it will put very little contact pressure on the batteries even when latched down in the middle.

In that case just bend down towards both sides very slightly then relatch it and that should put more tension on the contact point with the cells. Fitting the anti-tamper screws can help make better contact as well.

If you're still not having much luck try a different brand of batteries - while there may be nothing wrong with these ones, different brands of cells tend to have slightly different length from positive to negative, slightly different shape and dimensions of the terminals etc - all within spec but on a system like this with dodgy battery terminal design it can make a difference.

[DBMandrake]

Sorry I can't help directly but I'm having an analogous issue. My kit has been fully installed for 23 months and the original batteries are now starting to fall over like dominoes. I guess I may have been lucky with the original batch but it was beyond my planned expectation so I laid in alkaline replacements in expectation of an 18 month life cycle. As I replace the original batteries the replacements are mainly showing only 2 bars and the Evotouch is reporting periodic alerts. Those displays are only indicative I know and maybe capacity has dropped in the meantime.

As a result, I'm now following Paul Lockenden's advice and installing lithium Energizers simply to move on.

Every situation has different characteristic and usage of course but without stable local batteries my whole system has started falling over.

What is the voltage of the Alkalines you had in stock ? New they should be 1.61 volts. They don't have to fall too far below this before they'll report 2 bars, so its pretty normal for them to drop from 3 bars to 2 after just a few months but then they will stay on 2 bars for a year and a half or so.

I only use Alkalines on my system, previously I've used mainly GP Ultra from batterystation.co.uk as they're available in 40 packs at a good price, but recently I bought Varta as they were out of stock of the others.

I tend to have a 40 pack on hand not just for the heating but for the numerous toy cars etc our 4 year old has, so the packs of cells only stay in the house for maybe 6 months. Buying them a couple of years before you need them probably isn't a good idea.

I would be checking the battery contacts on yours, intermittent low battery alerts long before you're expecting them or with newish cells is usually due to poor connection with the battery contacts.

They're soft as butter so tend to sag over time. To test them I hold the HR92 with one hand and swing it down to thump it in my other hand - if the contacts are marginal it will usually cause the device to black out and reboot, if so the contacts need attention as you should be able to thump it down into your hand with moderate force without it rebooting.

With the batteries removed I use a small jewlers screwdriver through the bottom to bend the middle section of the two bottom battery contacts up a bit. It takes a little care but its easy when you've done it a few times. As mentioned in my previous post sometimes even the top shorting bar can bend out of shape as its so soft.

Yeah it's pretty poor that the battery contacts on the HR92 are so unreliable, but it is what it is and I've come to terms with it. I've had to retension the contacts on all my HR92's over the nearly 5 years I've had them to keep them working properly - some more than once now.

One new HR92 needed contact tensioning right out of the box as it was only reporting 2 bars on brand new batteries when I first tried to install it. Sure enough after tensioning the contacts it started reporting 3 bars.

Honeywell please take note and redesign your battery contacts using proper spring steel...

[G4RHL]

Sorry I can't help directly but I'm having an analogous issue. My kit has been fully installed for 23 months and the original batteries are now starting to fall over like dominoes. I guess I may have been lucky with the original batch but it was beyond my planned expectation so I laid in alkaline replacements in expectation of an 18 month life cycle. As I replace the original batteries the replacements are mainly showing only 2 bars and the Evotouch is reporting periodic alerts. Those displays are only indicative I know and maybe capacity has dropped in the meantime.

As a result, I'm now following Paul Lockenden's advice and installing lithium Energizers simply to move on.

Every situation has different characteristic and usage of course but without stable local batteries my whole system has started falling over.

Set a reminder in your diary to change all batteries once a year. Perhaps sooner than needed but it avoids problems and sporadic failures at different times. I have not found lithium’s make much difference to longevity but in my HW sensor they reduce the volume of lost contact readings.

[bruce_miranda]

I can now confirm with some certainty that the HW sensor lost contact has nothing to do with batteries. Mine has been hardwired to the same PSU as my wall mount and I have still seen them, mainly through the summer, when the DHW isn't Evohome controlled. Those lost contact messages appear to be a bug in the reception on the Evohome controller side.

[DBMandrake]

I can now confirm with some certainty that the HW sensor lost contact has nothing to do with batteries. Mine has been hardwired to the same PSU as my wall mount and I have still seen them, mainly through the summer, when the DHW isn't Evohome controlled. Those lost contact messages appear to be a bug in the reception on the Evohome controller side.

That's my conclusion too after extensive testing.

[G4RHL]

That's my conclusion too after extensive testing.

I am sure you are right but my lost contact messages reduced when I started using lithium batteries. I still get them, but never as many.

[bruce_miranda]

The errors are actually inversely proportionate to how much Evohome is in charge of DHW. I feel that when things are silent on the airways, Evohome gets a bit deaf and it only has to miss one of these extremely infrequent HW messages to report a comms failure and then because the next message is so far away, it takes a while to reset too.

[DBMandrake]

The errors are actually inversely proportionate to how much Evohome is in charge of DHW. I feel that when things are silent on the airways, Evohome gets a bit deaf and it only has to miss one of these extremely infrequent HW messages to report a comms failure and then because the next message is so far away, it takes a while to reset too.

I don't think its "deafness" changes, it's simply that when the hot water system is active (in the differential band and/or heating or cooling quickly) the sensor sends very frequent messages so if one or two messages aren't received it's not the end of the world as another message will be sent in a minute or so.

But when the hot water system is idle - especially if it's below the differential band and hot water is turned off with nobody using hot water (middle of the night) then the sensor can fall back to as little as one temperature transmission per hour. If a couple of those aren't received you have a "comms error". That's why these errors seem to happen much more frequently in the middle of the night or with hot water scheduled off when the house is empty during the day.

Battery voltage seems to have some effect on the power saving algorithm in the CS92A (lower voltage sends transmissions less often) ultimately it isn't the cause of the problem so higher battery voltage just serves to disguise the problem a bit.