So I'm thinking of getting a Watersnake electric outboard to replace the petrol motor. Just a moderate size one will do, but I have to carry a battery to drive it and to take the weight off my ancient bones, I'm thinking a lithium battery. So what size lithium would I need to drive the Watersnake ? .Or is it a completely bonkers idea.

Sam, I think the water snake is a trolling motor, it will drive your tender about rowing speed. A lithium battery to power it is a reasonable proposition, you will unfortunately attract the need for a fire extinguisher.( dumb as regulations if you have a battery you are required to carry a fire extinguisher ) the torpedo elec outboards have a nice clip on battery, but are stupidly expensive for what they are. Sam how far out is your mooring ?

Sam, You don't need to spend heaps of cash on a Watersnake.

I just get a cheapy from eBay every few years like this:
www.ebay.com.au/itm/383274096499?hash=item593cea9773:g:HvEAAOSw-T5h9jtP&amdata=enc%3AAQAHAAAA8M060EBPg%2BwnmVnMrGwgmBy7BqhGaDntVSDsQwalbyZINS7umch5n%2FSAJt4i0sIyo6T1LnYpIt4C6rPrbaDnIHiEUEqXFfs6RUwvnpnramcSf%2FEnVLSbEgzZpfvFN7b2H5maFgXHYZ8uuZsAPYBLs8OUVYdS2iQmBYgP69XBdaf1LxRcKNojFwdd0w%2F1zus7PfXbjdUx1PWVefqq7kd5XZgcAo2onqtxNyE5I8aZRfR6IzDwjEfmwAGZ9DJ8nWOcjKVPjnVaBZhQnHrQu85ugjoPeFSXp1LFAUb9sEF12aog%2BOH81lzw0q0WhKGc8qMkKA%3D%3D%7Ctkp%3ABFBM9Laar6hg

A lithium would be fine but a small lawn mower battery, with handle, works well for me - about $100 or so!!

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Lazzz said..
"Sam, You don't need to spend heaps of cash on a Watersnake.

I just get a cheapy from eBay every few years"

Yep, bought something similar, and mated it to a 40Ah AGM, small and reasonably light. - enough for a few trips to the mooring and back, or a weekend away with the kids having a bit of fun in the dinghy as well. TBH I don't treat it very well, but it's still working perfectly after 4 and a bit yrs. If it doesn't come with a 3 blade prop, source one to fit (also on eBay) - i found the difference helps with a small trolling motor. Mine is 55lb thrust - I reckon it's about equivalent to about a 2-2.5hp outboard, but no fuel, no oil, no tank, no smell, no problem starting etc. Can still get ashore in 30+knts. Covers all my needs, and when (or if?) it dies, replacement will be probly be cheaper than getting an outboard serviced!

I would forget about lithium. Very light but also a bit delicate. AGM is the way to go. Robust and surprisingly cheap.

Thanks for the replies guys. The boat is about 400 mtrs from the pontoon. A local bloke has an electric motor that pushes him and his 8 ft tinnie along quite well, but I don't know what his set up is. there's no rush, I might even wait for the boat show and see what's available.

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samsturdy said..
The boat is about 400 mtrs from the pontoon.

With one of these: www.batteryworld.com.au/U1-MF-Yuasa-YardMaster-lawn-garden-maintenance-free-battery

pushing a 45lb you would get easily 2 probably 3 trips at a good pace before charging.

3+ years at least.