Introduction: Briggs & Stratton InStart Battery Alternative

On a recent trip to the local supermarket I found a Lawnmower on special offer, 50% off. In the market for a new lawnmower a reduction from 430€ to 215€ was too good an offer to refuse.

However the reason it was on offer was because it was a Briggs & Stratton electric start model, and they had lost the battery and charger! I purchased it on the spur of the moment, thinking that I would buy a battery and charger and still make a huge saving. I hadn’t banked on the cost of a replacement battery and charger costing in the region of 140€!

Step 1: TinkerCad Battery Adaptor Design

I decided to try to adapt one of my existing power tool batteries to do the job. On investigation I found that a mini hedge cutter from Lidl had a rechargeable battery pack that was very similar in voltage and current as the Briggs & Stratton model.

I used TinkerCad to model the battery adaptor in two parts, one part would slot into the lawnmower battery holder and the second would hold the Lidl battery.

Step 2: 3d Printing the Parts

The Main Block

Printed in PLA upside down with a 0.2mm resolution and 20% infill. Adding support for the two side slots.

The Lidl battery holder
Again printed in PLA with a 0.2mm resolution and 20% infill. Support added for the height location ring.

The design and print files can be downloaded from Thingiverse,

or on my website My Project Corner

Step 3: Battery Terminal Connections

To make the connections between the Lidl battery and the Briggs and Stratton terminals I used some copper strips salvaged from an old light fitting.

As well as the inserting the copper terminals, I added a 30mm long x 6mm diameter compression spring into the center hole.

The copper terminals are then soldered to finish the unit.

Step 4: Using the Battery Adaptor

The battery tends to bounce around a bit if left in the adaptor, so I take it out while using the mower.

Other than that, it works really well & saved me 140€

Visit my website at My Project Corner for more details