Ecomower Battery Upgrade

14 Oct 2015

Finished 'test' version. (Minus balance lead which I added next).

I've just finished building a replacement battery pack for my Ecomower.

The original battery pack consists of 2 12V 10Ah Gel batteries which I got second hand via TradeMe.

The new pack consists of 84 recycled laptop cells (18650s Lithium-Ion) wired as 7 series groups of 12 parallel cells for a nominal voltage of 25V and 21Ah giving roughly 500Wh - or twice the capacity of the old Gel batteries when they were new. And it weighs 2 kg less than the Gel pack.

As you can see they are perfectly sized for their box. Lucky.

Next: add a BMS (battery management system) to help keep the groups balanced and to protect from over-discharging. In the meantime I'll use a balance charger to charge it and stick a Lithium cell monitor on it to warn of low voltages.

I tested it in the Ecomower and it worked great - but the cells are currently not charged so I'll charge them over night and mow the awn tomorrow and see how it performs in a real world test.

I'll give some more details on how I built it over on my Reusing Old Laptop Batteries page.

This is part one of a larger project to see how much can be done with recycled laptop batteries. Currently our local IT recycling center receives about 1000 laptop batteries a month - which they then ship overseas to be processed. I'd much rather see them re-used locally.

Cheers, Paul

Page last modified on 14 October 2015 at 11:13 PM