Lithiun-Ion Battery to run a house

[soundwave]

a m8 wants to run a batt set-up from his solar panels could a li ion bat be built this big and what parts would be needed for say 5kw battery.

like how many cells and what sort of bms for it ect

like this but diy
http://www.pocket-lint.com/news/133769-what-is-tesla-energy-powerwall-why-you-need-a-10kwh-lithium-ion-battery-in-your-home

 

[Deleted member 4366]

There's not really any advantage with lithium because size and weight don't matter. You can get 100Ah lead batteries for about £80. A lithium one would cost about £450. Lead is safer and self-regulates the voltage to an extent and self-balances the cells, so needs much less management.

 

[soundwave]

just an idea you mean like these

http://www.puredrivebatteries.co.uk/h3-varta-silver-dynamic-12v-100ah-car-battery.html?gclid=Cj0KEQjwjrqvBRD6wf2fy-C61PIBEiQAUzKQTmnoV81y2TzyUkgv4HShrkbL625q4WxwDu-poq70NdMaAuvo8P8HAQ

 

[Deleted member 4366]

That's a cranking battery for a car. For a home system it should be a leisure or deep cycle battery:
http://www.puredrivebatteries.co.uk/cxv31mf-110ah-dual-purpose-leisure-battery-by-numax.html

 

[soundwave]

he on a budget and a small 1 but that 1 in the link looks good

 

[Deleted member 4366]

It can't provide 5kw. He'd need a minimum 5 of them and some very hefty wiring. I'd use 6 of them for 330aH at 36v. Even at 36v, 5kw is 69 amps from each of them at the same time and 140 amps through the wires. 48v is probably the ideal because it's the highest you can go without having to worry about the Low Voltage Directive. The higher the voltage, the lower the current, so the cheaper the wires and the less losses you get.

 

[mike killay]

d8veh,
According to Wiki, you can go up to 75 volts if only DC, so he could use 72 volts.

 

[Deleted member 4366]

He has to comply with the Low Voltage Directive when over 50v in the UK, which means certified installation.

Edit: Apologies. 50v is for AC. For DC, you can go up to 75v. That's strange. I would have thort that it would be the otherway round, and I thought that's why we're limited to 48v for ebikes (EN15194). You can kill yourself with 75v DC.

 

[selrahc1992]

It can't provide 5kw. He'd need a minimum 5 of them and some very hefty wiring. I'd use 6 of them for 330aH at 36v. Even at 36v, 5kw is 69 amps from each of them at the same time and 140 amps through the wires. 48v is probably the ideal because it's the highest you can go without having to worry about the Low Voltage Directive. The higher the voltage, the lower the current, so the cheaper the wires and the less losses you get.

this is a very useful thread - does it have to be 5kw? I can well imagine juggling loads so that one wouldn't ever need more than a load of around 3kw, at most.

 

[soundwave]

so if he did go over the limit and got caught what sort of fine would he get out of interest?

tho i think he will be fine with the 52v for his needs. just small stuff lights tv ect

 

[mike killay]

d8veh,
years ago, I heard of a fatality from a 12 volt battery.

 

[Lardo]

We've had deaths from watch batteries, but I don't suppose you were talking about a 12v battery being swallowed!

 

[Arash]

Soundwave, I know a chap that sells lead acid batteries for cheap. He has some hefty ones at the minute (90ah) all tested and showing good capacity.

5 or 6 of them could probably run a house.

I know of at least one chap who lives off grid and a few more who use old lister stationary engines mated to gensets running as chp (combined heat power) and they have so much excess heat that they use a hot tub as a heat dump. Just need space and understanding/deaf neighbours.

Best of all they are run on used cooking oil and fat derived fuel so besides the effort its a very cheap fuel to produce and reduced enviromental impact.

Having tried grid tie ins, thier opinion was that its a waste of time. The certification is too costly and you get shares that you are supposed to flog to companies who want to offset thier carbon foot print. But its done on auction type areangement and too complicated for typical householder to do.