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31

Automotive headlamps are the obvious, easy 12V choice, being typically in the 45-55W range (don't get LED headlamps.) If you ask the right folks you can often get dual-filament bulbs (high/low beam) with one filament broken for free.


20

Another answer by Fresh Codemonger suggests having two pumps, one on regular power and the other on your inverter. I would like to suggest a similar option that I think is more efficient. As the other answer says, you should have a second pump. However, instead of connecting it to your inverter, your second pump should be one that is designed to run ...


19

Acid cell and Alkaline Batteries function by a process of controlled corrosion of two different elements which creates a voltage potential and a current if the circuit is completed. This process is in continuous motion from the day of manufacture, while it sits on the shelf in its packaging, while installed in the equipment during off/idle periods. It ...


14

You don't need to step up to mains voltage, in fact for experimenting it's best not to. There are such things as 12V car fan heaters that are typically 120-150W. Or you can buy wire-wound load resistors. A 3 Ω resistor would dissipate 48 W at 12 V, so wiring 3 in parallel would work and allow you to adjust the load. I'd buy 100 ...


11

Your hedge trimmer sounds like it has died or is in the process of dying. A quick google search confirms that this can occur with Black & Decker hedge trimmers, although it does not appear to be wide spread. Because you didn't provide the model it isn't possible to give you a more specific reason why it has failed. My opinion is that when you were ...


10

I think the easier thing to do is to have two sump pump connected. The first on household power and the second on your battery. The first would have a start sensor at a lower spot than the battery sump sensor. This way the battery one only runs if the water reaches above a high spot. This will also give the added benefit that if the household sump pump ...


7

Since you have an old car battery, the cost of damaging it by overcharging isn't much ($40?) and that would only happen if it got a lot of sun over weeks. A small home solar system might have thousands of dollars of batteries, so standard practice has long been for those to always have charge controllers. For small systems the cost of a charge controller ...


7

If you can not find someone to take care of the acid for you, it is possible for you to dispose of it yourself. this page which references batterycouncil.org which most discreetly describes the process outlined here that states: Gather together all the acid you need to dispose of and put on some sort of concrete pad. The high acidity may harm grass and ...


6

If you are willing to sacrifice a battery charger, you could gut the charging circuitry out of the charger housing and wire it as a battery dock.


6

Yes on battery removal. I've had better luck with name brand batteries. Before you pitch the lamp, try some vinegar, scraping off the scale ( I used a cotton swab soaked in vinegar) then neutralize with baking soda and finally rinse with water. I just resurrected a kitchen timer this way. I think ( but don't know), that the battery chemistry is more ...


6

Get a UPS No, not that UPS. An uninterruptible power supply, also known as a battery backup. This is a box that takes normal AC (e.g., 110-120V in the US) and uses it to charge a battery and power your devices. If power goes out (technically: voltage out of range) then it uses an inverter to power your devices from the battery. All automatically. You ...


6

You've got a few problems/misconceptions. First there's no such thing as a 100-amp battery; however 100 amp-hour would be typical of a car-battery-sized thing. An amp-hour is an amp for an hour. Second, you can't get 100 amp-hours out of a 100Ah lead-acid battery, at least not for very many cycles. That would be 100% depth of discharge, and that is very ...


6

For 12V DC, you are probably looking for halogen bulbs, not incandescent. You should be able to get a few hundred watts of 12v halogen bulbs for about $10 online, and you could even get them in units of 20W or so if you want to refine your testing.


6

As you know the battery voltage will fall as its charge depletes. Depending on how constant you want the load to be it may need to self-adjust to hold a steady load (wattage). Ham radio enthusiasts routinely require a "dummy load" for testing radio transmitters without actually transmitting anything. These are basically high-power 50 ohm resistors. On its ...


5

It is generally always recommended that the batteries be removed from devices that are not in use. Even the device manufacturers recommend this. I'm not sure what actually leads to batteries leaking other than a failed seal. It is possible that a device exposed to wide temperature excursions may make the battery seals more prone to failure. There is more ...


5

Buy a (petrol-fired) air compressor and pneumatic tools, or go for a bigger generator. (Good) Inverter can cost nearly as much as a generator, also remember that an inverter rated for 2kW has a substained rate of about half. I found on Amazon this 3kW inexpensive inverter, check if it may be good for you. Anyway, with an inverter it's important that the ...


5

Officially what you are actually asking for is a constant current sink: something which uses the same current even if the voltage drops. A light-bulb does that somewhat as it has a PTC thermistor characteristic (The resistance increases when it gets hot). If you really want constant current you would need to build something electronically. That is ...


5

You don't want to do that. An inverter powerful enough to start a sump pump will also have high standby losses. It will burn your battery down in short order. When you're dealing with a 12V system this small, you want all the loads to be DC. It might be tolerable if you only spun up the inverter for the second per day the pump was actually in ...


4

For one, the magnetic field generated by the magnets are going to be small potatoes compared to the magnetic fields generated by the motor while in use. Two, battery chemistry is essentially unaffected by ferromagnetic fields of the magnitudes you'll encounter in everyday life. Thirdly, there exist specialty tools that have a big magnet on them out of the ...


4

The neck style battery pack typically held an extra 1-2 NiCad cells in that neck portion. With the transition to higher voltages, they want to make at least some change in design so you can't use the wrong battery like @Henry Jackson stated. But the main reason you don't see any is the way lithium-ion packs are constructed, yes they do still have a few ...


4

You have the basic concept down. Your challenge will be sizing. What's the minimum possible load you can put on the system? For instance, don't use an inverter to run lighting. Run the lighting direct off 12V, and there's a huge variety of 12 volt LED lighting: from screw-in bulbs, spot or flood lights, LED strips that let you freestyle your lighting, ...


4

Measure each battery individually, you can still do that with the wires you have added attached to the battery. I suspect your batteries don't have a full charge. Your logic is correct.


4

That charger device clearly states that it is for NiCd and NiMH rechargeable batteries only. It would be a risky proposition to put other batteries in that unit whether they be lithium or alkaline types. I think it would be just too easy to put the unit into the wrong mode. What you want to do instead is get yourself a digital multimeter that can measure ...


4

3% hydrogen to air is explosive. Even sealed batteries discharge some hydrogen gas when charged--they have to release the pressure or they will break the case. The seal is accomplished with a rubber (or silicone like material) over the port and usually a plastic shield welded in place to keep the seals in place. These batteries are not designed to be ...


4

There are 'off the shelf' battery tester/electronic loads which handle up to 20 A/150 W at a fairly nominal price (considering that they have some degree of monitoring built in) - assuming that you are not really interested in designing your own here. These use some sort of power FET coupled with a fan/heatsink and constant current control. For clarity, ...


3

There have been a lot of changes in batteries for tools over the years. Different chemistries, voltages, capacities. Obviously the tool makers don't want you sticking a 20V lithium battery into an old 12V nickel-cadmium drill, so they make the shapes different. Maybe some of the discount manufacturers try to turn over their battery types regularly to force ...


3

I'm going to second mikes advice about wearing rubber gloves and safety glasses, especially if you can't guarantee that the container is properly sealed. If you get any on you, simply flush with lots of water, and apply a paste of baking soda and water to neutralize (I would flush first while someone else mixes the paste). For transport, just make sure that ...


3

The Powerwall is/will be based on the lithium ion battery technology used in the Tesla cars, so instead of a few large lead acid batteries (like in PV battery banks) it will contain a zillion tiny 18650 cells, which work better if you put them in series and let the voltage soar. This keeps the current low while still allowing the same amount of power output ...


3

AC power cannot be stored because AC is dynamically changing (to be more precise, alternating). It requires very expensive hardware to arbitrage it for other types of energy which are storeable, and in the sizes you need, the cost of that hardware is well beyond the scope you established in your question. That leaves: Hand tools. Exercise your arms. ...


3

Small colored wires like this have an enamel coating that insulates the wire so that it does not short out to other wires or metal objects/surfaces. It is this coating that is making it so that you cannot just twist the wires together to complete the circuit. The conventional way to rejoin wires of this ilk is to twist and solder. But first it will be ...


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