Charging off the grid. - Page 1
Forum section: electronics / general

author: davelectronic
author_rank: Frequent Contributor
timestamp: November 10, 2021, 06:24:38 pm
content: Coming soon I've a problem that is going to last at least 3 months. The building I live in has to elevators, both will be refurbished over a 3 month period. But not at the same time, I'm almost at the top of a high rise tower block, and a mobility scooter user. Normally if the elevator breaks down it's only for a few days, and I have a garage (no power point) I charge the scooter with a large 115 Ah 12 Volt battery my Son takes down on a sack barrow. I use an inverter to power the 24 Volt charger. Although I do have to limit journeys to essential only trips, keeping them short. But now I'm faced with 3 months solid of no elevator use, I was wandering if I could put two 115 Ah 12 Volt SLA batteries in parallel for more charging time. I know it's very wasteful of power using an inverter to power a mains voltage charger, but I can't think of any other way to charge the scooter, not having any power points. Maybe I could use a wind generator to charge the SLA batteries, my housing scheme might allow a small wind generator just above the garage door.. But I'm certain solor power is out of the question. Could there be something I have missed that could charge the scooter, with out my Son lugging the SLA batteries down two flights of stairs and out to the garage for every charge / SLA batteries recharge. Thanks for reading, any help appreciated.

author: antenna
author_rank: Frequent Contributor
timestamp: November 11, 2021, 02:47:08 am
content: What about getting one of those light bulb socket to outlet adapters? Surely you have a light wired in the garage!?

author: NiHaoMike
author_rank: Super Contributor
timestamp: November 11, 2021, 03:01:19 am
content: Take a look at R/C chargers, there are a lot of DC input versions since it is common for hobbyists to charge (light but expensive) aircraft batteries from (cheaper but heavy) portable batteries in the field.

author: davelectronic
author_rank: Frequent Contributor
timestamp: November 11, 2021, 01:45:36 pm
content: Thanks for the help. Those old light power fittings I remember well from years ago in the UK, my Grandparents had a few. Unfortunately I don't even have a light fitting in the garage, it's just an empty garage sadly. I'd never have thought of RC high power chargers, I will look into these and see what I can find out about using one for this application. I've looked round at wind turbines, never thought they'd be that expensive. But cheaper one's all have poor ratings, over a grand for a wind turbine is beyond logical for my use for 3 months.

author: Ian.M
author_rank: Super Contributor
timestamp: November 11, 2021, 02:09:02 pm
content: IANL, but it would be reasonable to expect your block's management to provide charging facilities for either your 115AH battery or your scooter for the duration of the elevator repair work that prevents you charging your scooter yourself, as a temporary adjustment under the Equality Act 2010.See ifhttps://www.citizensadvice.org.uk/housing/discrimination-in-housing/taking-action/asking-for-adjustments-to-help-with-your-disability/is any help.You may need to schedule when you can access the battery being charged with block management, so once you have an agreement, it may be worth getting a second 115AH battery so you can simply swap them.

author: davelectronic
author_rank: Frequent Contributor
timestamp: November 12, 2021, 02:37:17 pm
content: Yes I've telephoned my housing management, as I received a letter giving me a number to call if I'm or anyone else in the building is likely to have problems with mobility. I'm not holding my breath, after calling the number of the housing management, I was told someone would call me back. That was 5 days ago now, no one's called me as yet. I do have a little breathing space of a few months, as work starts on the elevator serving the odd flat numbers starts first. My elevator is serving the evens flat numbers. I've got more chance of going to the moon than getting a charging facility put in place (power point) there is no cabling even close to the garages that are for residents of the tower block. I don't have to pay for the use of the garage at the moment, it was given to me to use 2 years ago when the building flooded taking out both elevators. I've got to come up with something easier that asking my Son to traverse two flights of stairs with a 25kg SLA battery to the alternative elevator, when our elevator is out of service. My housing management isn't the easiest organisation to communicate with unfortunately. So it's up to me to find, or at least try to find a temporary solution.

author: ejeffrey
author_rank: Super Contributor
timestamp: November 22, 2021, 07:19:16 pm
content: Rather than put the batteries in parallel I would just use one at a time. That avoids worrying about matching the state of charge between the two batteries. Otherwise when you connect them a large current can flow between the batteries. You could also bring one up to charge while having the other available for use. It doesn't solve the problem of actually carrying the batteries but would give you more flexibility on when you do it.A reasonable accommodation would be to give you access to a janitor or utility closet with a power outlet for the duration of the work. Are there any places on the property you know of with a ground level power outlet that are secure enough for your use?How much power do you use in a day? Is there anywhere you could put a small solar panel to keep the SLA charged? That wouldn't be super cheap but it would be less than running electrical service to a stand alone building.