Customer question (received via email 25th January 2021):
Hi, I am looking for a solar solution to maintain 110ah leisure battery whilst the caravan is in storage. I dont need high performance for top up whilst the caravan is in use just permanent winter maintenance. The caravan is under cover. We have a South facing Window about 8m from the battery Box. Will the suggested system work through the Window or do we need to mount the panel out side. I prefer a solution to simply click onto the battery in November and be able to leave it until we go back the next spring. I look forward to hearing from you
Willgen Reply (Email from Bill 25th January 2020):
Many thanks for getting in touch.
The best option, if it is possible, is to mount the solar panel outside on an un-shaded South facing wall. The solar panel comes with mounting holes at each corner allowing it to be easily screwed to the surface of a wall.
The solar panel will still work behind window glass but output will decrease slightly. Keeping the window clean will help and we can supply suction cups to enable the solar panel to be fixed to the window glass itself. Please be aware that partial shading of the solar panel by window glazing bars for example can quite drastically reduce solar panel output so that should be avoided if possible.
If mounting the solar panel outside, to maintain your 110Ah battery through the winter months, a 10W Optimate Solar Charger is just very marginally too small. For peace of mind I would recommend a 20W Optimate Solar Charger.
If mounting inside behind a single piece of non-tinted glass (no glazing bars) the 20W Optimate should still be sufficient. If the glass is likely to be dirty or there is any shading I would recommend going for the Optimate 40.
You will also require an extension cable to cover the 8m between solar panel and battery. The solar panel comes with a 3.15m lead and the extension cable (bought separately) is 4.6m. The charge controller and battery connection leads give you another 1.5m of "reach". You can connect a second 4.6m extension cable between the solar panel and charge controller if absolutely necessary but it is better to avoid doing this if possible.
The products I have mentioned above:
Optimate 20 Solar Charger
Optimate 40 Solar Charger
Optimate Suction Cups
Optimate 4.6m Extension Cable
I hope that this helps; if you have any further questions please ask. All Optimate products are currently in stock and ready for rapid despatch on receipt of an order.