Portable car batteries and chargers aren’t significantly regulated and as Consumer Reports has noted, some manufacturers’ performance claims are dubious. Always read the fine print. For safety, look for batteries that are certified for compliance with Edison Testing Labs/Intertec or UL standards.
Always think about temperature. Manufacturers recommend not storing batteries in high-temp environments. If you want to keep a battery in your car, keep it out of direct sunlight in the glove box — or better — the trunk. In the summer months, it’s better to grab it when you start your trip and take it out of the car when you get home.
Then there’s the other extreme. Anyone vaguely familiar with batteries knows that they’re not terribly fond of extreme cold. Consumer reports found that when both the jump starter and the weak car battery were cooled to zero degrees, the performance of even the best portable jump starter options degraded significantly. If it’s really cold out, warm the portable battery indoors or inside a car first and keep it as warm as possible before you use it to jump a vehicle.
Chemistry does matter when it comes to the care and feeding of a car jumper. Conventional sealed lead-acid cells are heavier and discharge more rapidly than lithium ion batteries when they sit idle, but they can also be less sensitive to temperature extremes and to significant physical impacts. Either way, the care strategy with sealed lead-acid or absorbent glass mat is straightforward. Keep the battery charge as close to full as possible as much of the time as possible.
The chemistry of your portable jumper’s battery matters when it comes to caring for it.
“When you get it, charge it fully,” says Dan Portwood, senior product manager at Baccus Global, a manufacturer of multiple jump-starter brands. “After you use it, for a jump or something else, recharge it fully. If it sits idle for a month or two, recharge it fully. That limits the amount of sulfur in the cells and ensures both the maximum capacity and the longest life.”
Whatever the chemistry, it’s virtually impossible to overcharge a jump-start battery. That means you can plug it in and forget it for days at a time. Yet Portwood doesn’t recommend charging all the time. That keeps the charge block consistently warm (whether the block is external or built into the battery case), and can shorten its useful life.
The lithium-polymer cells in more compact car jump starters and chargers hold more energy for the relative size. They also hold a charge longer than sealed lead acid when they’re idle, but they can be a bit more finicky. To maximize performance over the long haul and ensure maximum life, a more active approach might be in order.
“If you have a reputable brand with good cell structure, you have a good foundation,” said Chad Estevez, a product support specialist at Antigravity. “Try not to store it in temperature extremes, and don’t leave it sitting for a year at a time. Treat it like a cell phone and exercise the cells. Use it every couple of months. Drain it a bit in some fashion, and then put it on the charger.”
Comparison of portable car battery chargers
| Model | Starting amps | Capacity | Weight | Features | Price |
|---|---|---|---|---|---|
| Antigravity XP-10 Micro-Start Battery | 300 | 18 aH | 18 ounces | AC and 12-volt recharging, two USB ports, LED light | $160 |
| Antigravity XP-10 HD Micro-Start Battery | 300 | 18 aH | 20 ounces | AC and 12-volt recharging, two USB ports, LED light | $198 |
| Black & Decker Power Station PPRH5B Battery | 300 | 17 aH | 20 pounds | AC and 12-volt recharging, air compressor, 500-watt AC inverter with two plugs, USB ports, LED light | $179 |
| DeWalt Digital Power Station DXEJ14 Battery | 700 | 21 aH | 16 pounds | AC and 12-volt recharging, air compressor, two USB ports, LED light | $158 |
| NOCO Genius Boost Plus GB40 UltraSafe Battery | 350 (est) | 4.8 aH | 2 pounds | 12-volt recharging, USB port, flashlight | $100 |
| Schumacher ProSeries 2250 Jump Starter Battery | 550 | 22 aH | 31 pounds | AC and 12-volt recharging, 400-watt AC inverter with two plugs, USB port | $211 |
| Schumacher Ultracapacitor Hybrid Jump Starter | 900 | 2.2 aH | 8 pounds | 12-volt recharging, ultracapacitors | $332 |
| Stanley Simple Start Battery Booster P2G7S | 300 | 2 aH | 2 pounds | AC and 12-volt recharging, USB port, LED light | $50 |
Written for CNET Cars by J.P. Vettraino.
