Battery sizing for electric bicycles

[wunder]

OK, sorry I missed the 84 watts. How many hours to recharge 3 hours each bike ? 84x3= 252 watt hours per bike ? x 2 bikes = 504 wh

Yes, that seems pretty close to what it has been running.

When do you ride the bikes Noon ? Morning ? Evening ? It matters because you will either be charging directly from the sun, or storing power in an intermediate battery.

can be any time, actually, usually around noon

100w HF panel. Sadly, it's turned out that the cardboard the panel comes in, is more valuable than the panel. But while it's working, great

Lol, I know HF has a bad rep on these forums. I bought them because I needed an energy source on short notice last August and renting a generator was twice what the panels cost. They were perfect for my needs and as far as I'm concerned, they've already paid for themselves. Anything else I get from them at this point is a bonus.

The most practical battery is a cheap battery, generally a 80ah 12v battery. 100w charging it, is barely sufficient, but it's all in the timing.
, using the inverter to charge the bikes in the morning so solar can recharge the battery in the day, is preferable to using the inverter to charge at night, and letting the battery sit drained all night.

The longer and deeper a battery is discharged, the shorter it's life, you want to maximize solar utilization.

Got it

Sump pump. Would a 12V marine bilge pump, if it meets the flow and lift requirements, be a option to avoid an inverter ? How often does Grid power pump fail and what expense are you willing to go to for a 80% solution or do you need a 99.5% solution ? If grid fails, that means storm which means no solar for recharge .

Actually our power here is super reliable and I may never need to use this option, but I want it just in case of emergency. If my basement flooded, it would be very expensive for me.

Thanks for the information!

[Sunking]

Actually our power here is super reliable and I may never need to use this option, but I want it just in case of emergency. If my basement flooded, it would be very expensive for me.

That is funny stuff, I do not care who you are. Who wants to educate this fool his 100 watt panel and his toy sized 12 volt battery will be dead long before he can pump the water out of his basement.

Give you a better idea and it would work a lot better. Make a contraption to use your bike to run a pump and peddle like crazy for a few days. It wil work better and move more water. Won't do the job, but a lot better than a 100 watt panel and a car battery.

[wunder]

Fun fact- this message board has a twit filter! That will make things much nicer for me going forward. Have a nice day Sunk boy.

[Sunking]

Fun fact- this message board has a twit filter! That will make things much nicer for me going forward. Have a nice day Sunk boy.

Here is a Fun Fact for you. If you had been smart and asked how to do this right from the start I could have saved you a ton of money with about 90% efficiency. No 12 volt battery, Inverter, or even your bike battery charger would be required.

I would have told you to buy yourself a Genasun GVB-8 Boost Controller. It is a buck/boost controller made for golf carts and can use a panel wattage as low as 100 up to 350 watts. They are made for 12, 24, 36, and 48 volt batteries. The 36 volt model charges at 42 volts a perfect fit with no waste. You may not like the message, but the absolute best advice anyone could give you. Your way just suks and now you know it and kicking yourself. .

Your idea of using your system to run a sump pump is not going to work for you. Will not even make a down payment for what it would really take.