A Varta Professional Leisure VRLA battery I have has no caps even under the label, the ABS casing is totally welded apart from the emergency vent port.
There is no way that's electrolyte will be being topped up without drilling into it.
Quote: Originally posted by david8858 on 17/11/2015Watts = volts x amps so 40watts equates to 40/12 or 3.333 amps. My maths is not good as several maths letcherures told me when I was younger
40 watt solar panel will deliver max 3.333 amps.
This may take a long time to charge a 110Ah battery!
It may trickle charge it.
Distinct lack of sun here recently so perhaps expect less amps!
Yes, it would take a long time for a 40 watt panel to charge a FLAT battery, especially during the winter months, but the amp-hrs required to counteract any ongoing discharge would be a lot less.
Typically a caravan with tracker and alarm will put a drain on the battery of about 200 milliamps ( 0.200 amps ), and a 40 watt panel will be more than enough to replace this loss. It's always worth checking whether the panel is still working.