Newbie - Need help

I found that you can get more out of 2 x 6V 215 Ah batteries wired in series. The cost should be less than 2 100Ah and you have less of an issue then wiring 2 batteries in parallel.

.384 w ~ .4W
.4w @ 13V = 0.031A to charge 8 batteries ( 2 chargers, 4 batteries each, if I understand it right ) is not right.

8 bike batteries, on trickle charge of .25A each = 2A @ 13 v = 26 watts - at the very least. x 24hr = 624 watt hours daily to keep the chargers ( 8 motorcycle batteries ) going.

Not wanting to be argumentative, to guide you with realistic #'s, I'm doubting the terms you are using,

8 batteries, not sure were you got this info from? I will not be in my workshop till the weekend, I will check the Ah of 'both' batteries & add this info to see if this helps with answering my question.

Thanks,

Andy.

What you need is how much power is consumed by the charger when it's charging. Not the Ah of the batteries being charged (although based on the Ah of the batteries being charged, people can probably make an educated *guess* at the power needed for charging.)

I think you should borrow (or buy) a kill-a-watt meter, and plug the charger into that, then see how much actual power is used when it is charging batteries. (Is it really charging batteries, or just being used as a battery tender - ie - making sure you don't have a dead battery when you haven't started the motorcycle in weeks?) Looks like it can output to the battery ~0.8A, 12V. Which would be 9.6W. That's probably a good enough number - if it's being used as a tender, it won't be that high.

Probably your best option is to pay an electrician to run electricity out to this garage. You can probably get it done for less than the cost of the off-grid system. And I'd think the owner would be willing to let you do it - since it'd be improving his property.
Second best is probably to use an extension cord (or maybe 2, to two different circuits if you're going to be running grinders, drills, and other things with motors.)
Third best option is probably a generator, or a good inverter hooked up to your car's battery when you are there.
Somewhere way way way down the list is an off-grid solution. I think it's well below finding a solar-power based battery minder for keeping the bikes' batteries topped up, and a couple of Li-Ion battery pack powered LED work lights/flash lights from your favorite tool manuf. (dewalt, milwaukee, makita, etc. etc)

PS - are you in the US or somewhere else? A kill-a-watt meter would probably be the US brand - if you're somewhere else, there's likely an equivalent.

I live in England.

Optimates are battery tenders not chargers.

The garage is not at my house.

A generator is not an option, the battery tenders need to be on 24 /7. The residents were the garage is located wouldn't appreciate one running 24 / 7, never mind all the pollution.

I'd have to look in to the third option on your list of suggestions.

Thank you,

Andy.

I read this as two chargers that manage 4 batteries, a total of 8 batteries


So, how many bike batteries will be maintained on charge 24/7 ??

Maintainers generally charge at 1-3% of the battery capacity

2 batteries.

OK, I see we're going to have do this a line at a time.

What size ( in Ah) is each battery ? 20ah 40ah ??

I previously mentioned I will be checking the Ah this weekend.