Best Jump Starter?

For only jump starting a Prius with a dead 12V battery, the cheapest jump starter box will do fine. If you have enough use to justify one to run an onboard inverter and air compressor, them one with high amper hour capacity battery will run the compressor or inverter for a longer time.

Good tips about keeping the jump start box under a seat, or strapped to a rear seat back etc.

 

I'm surprised there isn't a way to monitor 12V battery health in a Prius. As I understand it, for a 12V battery failure to prevent starting, it's got to be really good and dead.

 

I don't know, I had a 2005 Prius for 7 years, same battery, never had a need for jump start or flat tire. I guess I just live on the right side of the tracks. I hope I didn't just jinx myself. I guess I will gamble on getting 7 years more!

 

The best jump starter for Prius is a good friend.

 

I use a couple of 6V lantern batteries (dry cells) hooked in series and some #12 wires with alligator clips. It only costs a few dollars for the batteries, wires, and clips. It takes less than an Amp to boot the car up. Just unhook the dead 12V battery hook up the lantern batteries and start the car, once its in Ready unhook the lantern batteries and hook the normal 12V back up again.

 

I did not unhook the dead 12V battery when jump started from motorcycle battery. I think it is more safe.

 

I think it's fine to do it your way if it works, but there could be times when the 12V battery is too dead to allow a small battery to provide even the small amount of current needed. i.e. when the 12V is really dead it's internal resistance might be so low that all the current will go to the 12v battery, in that case you would need to unhook it until the car goes to Ready. Motorcycle or lawn tractor battery probably has enough capacity to overcome that but I am not sure about dry cells or power tool batteries which also work to boot the car.

Safety issue? just be careful not to ground the + terminal of the battery as always.

 

Safety for the car's electronics of course. In your case the 12V battery is disconnected and we jump-starting the hybrid system using something certainly not designed to match current parameters of Prius. Once the hybrid systems operates it wants to recharge 12V battery - instead of it there is something unusual hooked - which may "confuse" car electronics. I'm not an expert, but feeling fear of unusual behaviour of sensitive components I keep 12V hooked when jump starting.
It reminds me of my first motorbike Honda (hey! some 40 years ago ) - the battery was flat, I removed it to find new one, in the meantime I started the bike using the kickstarter. After turning on the lights all bulbs flashed bright and gone immediately. Obviously the battery resistance played an important role in the circuit's balance.
I realise how different things are - simple 50ccm bike and the Prius - anyway - since then I'm very careful with the voltage

 

Many years ago, Brookstone made a battery jump starter. It's basically 2" x 2" x 8". You plug it into your cigarette lighter. I have one. It works OK. I don't know if they still make it. But at least I don't have to carry one of those 20 pound jump starters with the compressors (I have one of those, too) in my car.

Mike

 

Mike, doesn't the power outlet in the Prius power down when the car is off? If so the one you mention would still be OK but you might have to cut the plug off and replace it with a couple of alligator clips.

 

You might have a point there. I never used it on my Prius, so that might be a problem. Good to know before I actually have to use it. Hopefully somebody smarter than me knows the answer (or do you know the answer and are just being nice to me?). But I'm sure you are correct that I could just cut off the plug, attached alligator clips and then attach directly to the battery contact points on the car.

Mike

 

^ If you want to preserve the original cigarrete light connection something like this might work:

Amazon.com: HobbyZone Alligator Clip: 12V Lighter Adapter: Toys & Games

 

Power outlets are down when Prius is off. Not quite usefull to this. I'm also not sure how 12V circuit is routed. I would think twice about the inverter.

 

In the front seat of a Triumph Spitfire fastback.

 

I just found this forum after unsuccessfully trying to jump my Prius with a Powerall battery charger. I see your mention of unplugging the 12V Prius battery. How do you do that if it's hidden away in the trunk that won't open? Or are you crawling in from the back seat? (I'd have to remove a child car seat to get in, so I'd rather not go that route)

 

I've been hooking up a charger periodically without battery removal, since day 1. No problems. I'd say it's not needed, just makes wear and tear. Do be very careful with polarity.

 

Most battery "chargers" are not intended to be used to jump start.

If it really is just a charger, connect it and let it charge for several hours and then see what happens.

 

I use one of these:

It also needs an extra part to work, because the lighter socket is dead when the power is off. You have to connect it to the jumper terminal located under the hood:


It's a fraction of the weight and bulk of most units which use lead-acid gel-cells, but has a similar-capacity lithium-ion battery. I like that it stows in the pocket between the passenger seat and door. I don't need one with a compressor on it, because I got one with the car, as part of the handy-dandy flat "flat-repair" kit. It tends to hold a good charge for many months, and it's also capable of starting a conventional vehicle. All-in-all a reliable solution for my application.

"Use" is not really the appropriate word, because now that I understand the system, I probably won't need to use it. I discovered that the acc-mode times out after 20 mins or so, which is fine for protecting a reasonably good aux battery from going flat.

My problem was that when I first got my car, my aux battery was going dead after about 10 mins on acc. My car was then dead in the water despite having over 4 kWh of energy on-board. The dealer tested the battery, found it defective and had it replaced.

 

I have one of these. It failed to work when I needed it, despite being fully charged. I took it apart, cleaned the connections and tightened the connections securely. It worked, but I don't know how reliable it will remain.

 

Mine was great for years. I bought one for work and within 2yrs it broke. It will not recharge. All of the connections look fine too. Grrr