My DIY Portable Jump Starter.

Here is how I made a robust lightweight portable jump starter for my car. I love the peace of mind having a spare battery to jump start any car in the event of a weak engine battery.

I got a 99usd, 210CCA, lifepo4 battery from Amazon.com that weighs only 2lbs. My actual car battery is 3lbs and uses the same chemistry! These lifepo4 battery are robust, long life and environmentally friendly.

Using this spare battery I went about creating a portable Jump Starter!

Step 1: High Current Connectors.

Using a pair of XT60 connectors, I went about making a means to easily connect and disconnect battery clamps to my nifty lifepo4 battery.

Step 2: Soldering.

Each XT60 is polarized. The flat side is for positive. I used my 100watt soldering iron to bond the heavy Gauge wires to the connectors.

I had a spare battery clamp with built in diodes to have worry free connections if the wrong polarity was made. If you have non diode protected spare clamps, just verify polarity before connecting the a depleted car battery.

Step 3: Connection of the Battery Leads.

Connecting the leads with the supplied bolt and nut was easily. It's important not to over torque the bolts. Each bolt can be tightened with a 10mm spanner or a Phillips head screwdriver.

Step 4: Insulation!

Using liquid tape in generous volumes, I insulated exposed conductors at the XT60s and at the battery terminals.

Step 5: Completion!

Here it is! My new portable Jump Starter! Since this is based on an engine start battery, I expect the lifespan to be long just like the one for my car's engine.

I had a spare pouch which I used to bundle my latest creation into. Looks neat now!

Not bad for 99usd eh.

Comments

[chetannaik24]

Better to use jump start cables than soldering wires to the battery so as to avoid the free end of the wires from touching each other

[charvey0318]

How do I use that to charge my car battery I don't understand

[wwoef]

LiPo batterties are very dangerous! If stored at full charge they will swell first and possibly explode! See for instance this video: https://youtube.com/embed/hg3r2erRrfw?start=21&autostart=1.
I would advise to do this with standard lead batteries rather than LiPo batteries.

[MagnumAL]

Need a safety disclaimer to make sure the cables can not touch each other or cross the battery leads when storing. Store with the cables disconnected. That diode will protect against accidental reverse connection but a shorted lithium battery can melt metal and discharge fast enough to set you car on fire.

[gfihacsqb]

hello, whats the biggest displacement motor you have been able to start with this battery?

thanks for your time

[Mjtrinihobby]

I successfully started a Toyota Hilux, diesel 2.5L. The battery is quite a kicker.

[Powerofchoice]

Are you able to charge this like the smaller instant boost type jumper chargers?

[ramyerizer]

Can I use this rechargeable battery with this specs? thanks you very much!!!

[Mjtrinihobby]

Too low power density.

[MillennialDIYer]

What matters is the instantaneous current delivery. From those specs it isn't entirely clear. Post a picture of the whole battery, and where it came from.

[ΧωρίςΌ]

You know you can buy this for around $30 bucks in the USA?

[MillennialDIYer]

Thought the same thing. This project has become pretty much obsolete these days. Commercial versions are cheaper while being more portable and convenient.

[Tony.Broadhead.AKA.Tonesoft1956]

I too have the same setup my first one was a small size car batrery with jump leads bolted on works briliant but a bit heavy so i am now using a smaller size battery fited it into my car use a relay to switch over from inside the car going to put a charging circuit in to automatcaly charge the aux battery I needed this setup as i dont go on long runs and my main battety dies just below cranking so this setup helps keep me going trouble with modern cars are that they drain your main battery quicker because of the alarm system anx other pieces of electronics

[BruceN15]

that battery you used is designed for motorcycles, theres a lot of reviews on amazon that said it caught on fire, use a different brand lithium battery. I believe the type is iron phosphate or somthing, anyways FYI. also put in a on/off switch that can handle the amps. for a battery look up "Shorai LFX09L2-BS12 Extreme Rate Lithium Iron Powersports Battery" on amazon and read reviews

[BruceN15]

scratch the shorai battery, the reviews say it catches fire too. the batteries that work are 123 batteries, not sure which type but they are the 266xx type. look it up on google, and youtube "diy jump starter" or something

[Mjtrinihobby]

I have used this Lithium iron chemistry for years and with no problems. It is the safest Lithium battery commercially available.

[GaryH8]

Not bad!!
You may want to add that they can increase amperage burst using some type of capacitative discharger built in to your system. In cooler climates one might need a minimum of 75 amps on up too 900 amps to get started especially depending on how low initial battery charge. I use batteries with a minimum of 850 CCA and if my battery is dead. I need to recharge for 20 minutes with a 75 amp booster. Normally in the Snowy regions you just hope to God your neighbor can jump your auto or your auto died near a 110 receptacle and you have a charger.

[Cekpi7]

Good idea
You could also make case for it and add 12v socket or maybe usb so if you have this in your car you can charge your phone if battery dies

[Mjtrinihobby]

Future upgrades! Good suggestions!

[Meglymoo87]

Nice :)