Folding solar blankets are becoming more popular as prices fall and the technology improves. Around 160W is the current sweet spot for ‘average’ use, considering output, price, size and portability. Prices vary from around $190 to $600 or so. I’m always after best value for money in these things and have the technical gear to measure electrical performance, so I do. I purchased the San Hima 160W blanket to replace a VoltX 160W blanket that was stolen.
Things to consider:
- construction quality and methods. Solar blankets take a hammering so their ability to stand up to folding, unfolding, storage on the back seat, dragging through the dirt, being bent and twisted as you try to align towards the sun or stop it falling off the car bonnet are all important. Bending the actual panels is not good as it can crack cells or circuits, so stiff and strong panels are an advantage. The ruggedness and shape of the panel surface is also important to prevent loss of transparency and scratching, and also its ability to collect off-angle sunlight. ETFE coated panels resist heat, scratching and clouding better than PET. I’ve not tested any of this other than by visual inspection.
- the electrical performance - maximum power output, and temperature response (output reduces as the panels get hotter).
- performance in low light and cloud.
- performance in partial shade. Bypass diodes and the way the panels are wired (series or parallel or a combination) will determine how the blanket behaves when one panel or a group of panels are partly shaded. At worst, output drops to zero if just one panel is shaded or blocked. Better setups are more tolerant and may allow eg half normal output if half the panels are blocked. I haven’t checked this in this review, but will later.
- how easy it is to set up and point to the sun. The simplest is to lie the whole thing on the ground which works well enough in summer when the sun is roughly overhead. In mornings and afternoons it is better to sit the panels up at an angle to be more perpendicular to the sun, but this can be difficult to arrange. A few have support frames to hold them in position but most do not. They can be leaned against a vehicle or chairs etc and this works best for blankets with panels arranged in a single row. Two-row blankets like the San Hima are harder to organise this way, but should fit better draped over the vehicle bonnet, for example. Some blankets have loops or eyelets so you can tie them to various supports.
- accessories included and their quality. These could include a regulator, connecting cable, alligator clips to connect to battery, stand etc. All these blankets are built so they fold into a kind of carry case.
- weight, size and ease of storage
In this review I’m comparing qualitatively to my old VoltX 160W blanket that proved to be tough and reliable, produced around 8-9 amps and I would recommend.
The San Hima Build quality is good: neat stitching, straight panel alignment, solid connectors, and a generally tidy, robust feel. The coating is nobbly PET, the same as the VoltX and typical for budget products. I expect 3-7 years life, good enough.
My electrical testing was done in near‑ideal conditions – full sun at local noon, clear sky, ~30 °C ambient, and the blanket set a few degrees off-axis. Measurements were taken using the supplied 4.5 m cable.
Initial max output before the blanket got hot was 138 W at 8.5 A, with a maximum current of 9.0 A (this is relevant for PWM controllers). Once hot, the max output was 130 W at 8.7 A, again with 9.0 A max available current. These are reasonably good figures for a 160 W blanket in real‑world conditions. If you allow for the poor cable (see below), the output from the blanket itself was 152W, very good and not far off its specification.
This performance is roughly on par with the VoltX, possibly somewhat better. Physically, I prefer the VoltX’s single‑row layout, but I guess I’ll get used to setting up the 2x3 panel blanket soon enough. It should sit nicely over the vehicle bonnet. It also has loops that allow attaching it to supports. It is slightly larger and heavier than the VoltX, but still easily stored and carried. The two row configuration requires a bit more coordination and wrestling to set up, especially in dirty or muddy conditions.
The accessories are ok but basic which is probably not an issue for most people who will use their own regulator and cable. The MPPT regulator works as designed but like most low‑cost units it hunts too often and too slowly, interrupting output whenever conditions change. A PWM regulator might be a better match here because the blanket’s operating voltage is close to battery voltage, giving stable 8-9 A without the MPPT’s constant searching. While the regulator was able to deliver 120 W and up to 10.4 A at lower battery voltages, its average output to a 12V battery will not beat PWM, and it will be noticeably worse in changing light conditions (moving clouds).
The supplied cable was a disappointment. It’s well made and looks impressive but is electrically undersized. I measured 187 mΩ round‑trip on the 4.5 m lead (i.e. about 18 AWG), causing a 1.7 V drop and 17 - 19 W power loss at full output – more than 10% of the blanket’s rated power. It’s disappointing that the efficiency gained from using hi-tech HPBC panels is cancelled almost exactly by this low-tech economic saving. The cable is so small that it is not even rated to carry 9 or 10 amps in likely temperature conditions. If you do use the supplied cable, the high losses also mean that the regulator should be placed at the battery end of the cable to avoid the additional problem of premature charge tapering.
Overall: This is the cheapest 160W blanket in the current market and assuming it proves as rugged as I expect (hope?), it’s great value for money. It’s efficient, tidy, and robust and a good fit for my intended use. The beautiful looking but badly undersized cable is an unnecessary failing, and I don’t recommend using it.
Alternatives: AI produced this table of economical solar blankets. ETFE surface coating is more UV resistant than PET and will last longer with less clouding and scratching. The Wildtrak looks to be worth investigating.
San Hima 160W
Price: ~$189
Coating: PET
VoltX 160W
Price: ~$239
Coating: PET
Kings 240W (closest to 160W)
Price: $299
Coating: PET
Notes: No 160W model currently. Typical Kings budget build.
Wildtrak 160W (ETFE)
Price: $299
Coating: ETFE
Notes: Built‑in stand.
Perception Lighting 160W
Price: $529
Coating: ?
Ruggedised
KickAss 160W
Price: ~$389–$499
Coating: ETFE mono
