Homemade Powertank

[ScubaMike]

Below is my completed power-tank.

Parts list to follow.........

[ScubaMike]

Parts used & cost:-

85Ah Leisure battery - £45.99

http://www.ebay.co.uk/itm/190587542669

25mmx5mm angle iron - £7.00 from local towbar fitters

12mm Plywood - was lying around the garage.

Main cut-off switch - £5.21

TRIUMPH BATTERY CUT OUT SWITCH KIT - LUCAS - NEW L@@K | eBay

Connector blocks - £6.50

8 Way Metal Earth Block Connection Bar for Meter Tails | eBay

3x 12v cigarette sockets - £10.75

eBay - The UK's Online Marketplace

3x red LED switches - £5.97

eBay - The UK's Online Marketplace

Battery connectors - £2.55

2pc Battery Terminal Clamps Classis Modern Car etc Clamp type cable fitting V025 | eBay

Rope for handles £1.29 from B&Q

6mm sq wire to connect battery to connector blocks, 1.5mm T&E for other connections from garage.

Total Cost = just under £85 (including all the P&P charges)

I also added a 12v laptop charger @ £5.40

varnish, hammerite, screws would need to be added too if you didn't have them.

I will be extending the powertank to include a further 3 outlets, but the battery is big enough and there is plenty of expansion space.

[ScubaMike]

Build process:-

Cut plywood to 2 of each

300mm x 450mm - top & bottom

300mm x 250mm - small sides

250mm x 450mm - large sides

Cut 45 degree angles so plywood fits nicely together.

Fasten together with panel pins & glue.

Drill holes for power outlets, switches & cut-off switch

Cut angle iron (with 45 degree angles so it fits together without overlap)

Paint angle iron & varnish box (several coats)

Fasten angle on outside of box to strengthen and protect.

Fasten connector blocks internally.

Wire up & solder joints.

Fit battery & terminals

Job done.

Total about 3 hours spread over a week (could have been done in a weekend, but had other things on).

[yesyes]

Looking good... ;-)

How do you charge the battery? Through one of the outlet sockets?

[ScubaMike]

I have an old motorcycle "conditioner charger" I use (you can just see the bike in the backgound of the frontal picture). There was a spare quick connector so I just clipped the croc clips off it and permenantly wired into the battery terminals, and connect using that when not in use.

Keeps the battery at optimum charge.

I forgot that anyone building would also need to have a charger.

Also forgot, battery has screw holes in the base, so I spaced it up using a few washers and screwed through to keep the battery stable.

[spaceboy]

Great job Mike. Bet that will last for hours from one charge.

[ScubaMike]

The aim was to go for 8 hours on a single charge.

85Ah (less 20% as doesn't do to completely discharge them), give me 8A for 8 hours.

2A for mount,

1A for filterwheel

5A for laptop power

I should have factored in for dew heaters, but I probably have leeway for another 2A (as I won't be running the laptop recharger constantly).

If the worst comes to the worst, I can upgrade the battery to a 110Ah one (the box is big enough).