Most helpful critical review
5 of 6 people found the following review helpful
1.8w is more suited for vehicle batteries which are 30ah or less.
on 18 March 2015
The reviews about the Visua Solar Powered Battery Chargers have been combined with the sellers other listings for the various wattage being sold. It certainly misled me into thinking that the 1.8w is a worthy product for any battery. It's not. You'll need at least a 4w solar powered charger to trickle charge and prevent power drain to a 12v vehicle battery which is above 30ah. 4w is suitable for batteries which are also over 100ah.
Fully charge your battery before using these units. They are not designed to recharge a flat battery.
It is not recommended that anything higher than a 2w solar powered charger be used on vehicle batteries which are less than 30ah. The "ah" is shown on the battery.
Solar chargers above 4w can be used should you continue to experience drain on a 70ah battery or above. Power drain is different from one vehicle to another. These items replace a small amount of wattage within the hour on a sunny day and less when the day is overcast and cloudy. Therefore, it can be a matter of seeing what works for you.
The 1.8w (costing £16.99) was useless for the power loss from my 100ah battery on my 25 year-old BMW 3.0i alarm system. I purchased a 4w from a different manufacturer on Amazon. It's built in a durable folding case with stands and has a cigarette lighter connecting lead and a separate battery lead with clips. It also has a green LED light displaying when it is charging. The green light extinguished at night when it is too dark to charge. The 4w cost me just under £18.00. I'm making use of the 1.8w by using it in conjunction with the 4w, which has made a huge difference. Hence, a 6-7w would've been ideal to properly fix my problem.