Sandaysoft

Hi,

No, the Lidl charger is NOT suitable for recharging "Rechargeable Alkaline" batteries (because they operate at 1.5 volts and the "intelligent" charger is expecting the 1.2 volts of NiCd or NiMH cells). A "dumb" (fixed timer) charger might do better, but I tried trickle-charging my Rechargeable Alkalines (as might happen from a PV panel) and they were useless as well. I'm surprised that your cells got down to 1 volt, did you not get a "Low TX battery" warning icon on the console LCD before this? How long did your (supplied?) rechargeable alkaline batteries last? Mine managed about 3 months, but somebody has quoted only one week!

Actually, I believe that the PV cell IS large enough to run the transmitter (although the slope on the PV cell is inappropriate for our latitudes and/or users may wish to put the external module in a "shady" location to avoid excessively high temperature readings). In my case it is putting SOME charge into the battery, but the microcontroller in the "solar head" is consuming MUCH more current than is used by the transmitter. I hope to discover soon whether the solar head is actually faulty or if the overall design is just too "optimistic".

Cheers, Alan.

Thanks for the helpful reply, Alan. I had not realised that these were rechargeable alkaline batteries rated at 1.5v. Anyway your prediction of the time scale for the Duracells was right as they have now run out and I have to replace them. I want to replace them with a "trouble free" rechargeble battery that will last for some years. Any recommendations for replacement batteries would be welcome.

And why are there not hundreds of posts on this thread - it cannot just be the few of us that have posted that have the problem, surely. I'm in the south of England and the weather station has a clear view of the sun, surely the batteries are failing on everyone's station - or is it just me!

Will let you know what I do next and how it turns out - wouldn't recommend Duracells for anything other than a couple of months quick fix.

Andrew.

Hi Andrew,

The fundamental problem is that a significant proprtion of the 3080 Solar Pods (including mine and probably yours) continuously drain more current out of the battery than the PV cell can supply. So any type of battery is going to run out of charge in a relatively short time. My Solar Pod was replaced by the supplier, and I could not measure any "leakage" with the replacement Pod, so I have some confidence that at least the batteries should last longer now.

If you can't get the Solar Pod replaced, then the only solution may be to fit a larger PV cell yourself, since I haven't heard if anyone has identified which component (within the Pod) is draining the excessive power. However, fitting a new PV cell is not a trivial task as both the PV cell and the batteries need to be of the "right type". But I can give a little more advice if you decide to follow this route.

Cheers, Alan.

I too have this problem. Firstly I lost the Solar values on the receiver. After this the low battery icon came on. I replaced the rechargeable alkalines with some 2600NiMh's which lasted for a bit until they too went flat and I lost all data. In the meantime I got in touch with the supplier who sent me a new solar pod and some new batteries. This worked for about 24 hours. I now have no solar values - back to square one.

I have got back on to the supplier. Be interesting to see what they say. I'm not particularly impressed I have to say.

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Mick
Lincoln
http://www.lakestudio.co.uk/garden_obs

Thanks for the info, Alan. I have put the Eneloop batteries in and I have the "low Tx" icon already. I could test the Solar Pod and get another or I could send 3v from my shed straight up to the station - bit of a pain but it will either cure the problem or move it on to a new level. Am OK with a meter and a soldering iron and would appreciate it if you would outline your testing procedure so I can see if I have a leaky pod. I got my WH3080 from signatrol - are they good about sending out new solar pods? Also if I do get a new solar pod I must test it to make sure that it is not another leaky one.

Do the leaky solar pods still give good readings?

My last weather station was an Oregan Scientific WM918 that had the outdoor temperature sensor problem so this is a bit of deja vue all over again!

Thanks again,
Andrew

Hi Andrew,

The method I use is to remove the two AA batteries and tape two short, insulated wires (stripped at each end) one onto the positive end of one battery and the other onto the negative end of the other. Then reinsert the batteries with the wires at the lower (bridged) end with the tape preventing contact with the metal bridge. Now put a milliammeter or low value resistor (less than 20 ohms) across the wires to measure the current.

The transmitter draws pulses of about 25mA when transmitting (only 50ms every 48 seconds) but the rest of the time the current should be very low (generally tens of microamps, depending what is connected). My faulty Pod drew continuously about 300uA when connected (after a large pulse for a few seconds initially) which dropped (or even went negative) if enough light was present. The replacement Pod drained almost no current continuously. Note that the PV cell output appears to be regulated, so you may not detect any charging current unless the batteries are below about 3.0 volts.

Yes, my faulty pod produced satisfactory data, except the UV which is ludicrously high. Perhaps slightly more accurate Lux than the replacement (the first seemed high the second low), both give a rubbish UV index.

Personally, my experience with Signatrol, was excellent.

Cheers, Alan.

Edit: If you want to follow the solar charging route (assuming your leakage is not too high), the best type of battery is probably a single (3.2volt) Lithium Phosphate (LiFePO4) AA cell with a dummy (short circuit) cell in the second bay position. Not easy or cheap to find, especially with a rating above say 600mAh. Possibly the cheapest source of PV cells would be two (wired in series) from two Pound Shop garden solar lights. The cells should have a forward diode connected in series, preferably Schottky (low voltage drop) type, but you might be lucky and find one in the garden light. Note that one PV cell could be enough because the tiny circuit board in most garden lights carries a voltage step-up converter (the LEDs require about 3v), but modifying the circuit is not quite trivial (because there are various different types).

http://shops1.bizarsoftware.com.au/lite/grandcell/catalogue/c2/p3
I might give these batteries a try.

Hi,

I doubt if you'll find anybody (except the manufacturers) who have a good word to say about rechargeable alkalines.

If your transmitter works with 2.5 volts (and maybe you don't mind the "Low TX" icon permanently displayed on the console) then get some of the new technology "Hybrid" (low leakage or "precharged") NiMH cells branded as Eneloop, or many other names. If you need 3.0+ volts for transmitter range, etc., then IMHO a 600mA AA LiFePO4 (+ dummy cell) should work fine in Australian sunshine. Search ebay for LiFePO4 AA or 14500 (and read the specification carefully) but I'm afraid they may have to come from Hong Kong or China.

Cheers, Alan.

I got the soldering iron out and ran a cable from inside the shed to the battery terminals of the WH3080 and connected it to a 3v mains transformer. This works nicely and I'm back on line (www.harrywarrenhouse.com/weather/Weather.shtml) although while it was down the system seems to have logged 10m of rain!

Did you get the idea from Stevenw's Mains Power for the Fine offset WH3081?

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