What to do with a lead-acid car battery?

Piwoslaw · 12-30-18, 06:58 AM

I recently bought a new car, but it came with a cheap, undersized battery. For the engine Start-Stop function to work, I had to get a larger AGM battery. Now I have the old one as a spare.

What can I use a 12V, 510A, 62Ah lead-acid battery for?

I could keep it in the car, wired parallel, and delete the alternator, but the alternator doubles as a starter. And the ECU already turns off the alt field when the battery is topped off.
I would love to use it to catch solar or wind, but our house is shaded year-round under tall trees.
I could charge it at off-peak hours and power the house at peak hours, but our utility does not offer such a tariff, only flat rate.
I could just leave it in the garage, topping it off every weekend with a trickle charger, and use it for testing random electronics projects, but that seems like a waste of a nearly new battery.

Any other ideas?

EDIT: One more idea would be some kind of e-assist project for a bicycle or bike trailer.

Daox · 01-01-19, 04:21 PM

Unfortunately, a starting battery isn't really all that useful. You can't deeply discharge it without significantly reducing the life of the battery.

stevehull · 01-02-19, 04:37 AM

I use batteries like this for my electronic work. I do fuse it, but what you have is a virtually unlimited current source at a voltage that never changes.

For + - ground supply, I hook up two batteries in series and now have a ground in the middle with a + and - 12 volt supply. FAR better than commercial power supplies - and the price is right.

Some solid state stuff, especially analog, wants a very stable power supply. Bread boarding and prototype with the above configuration makes it a LOT easier as I don't have to be concerned with the stability and cleanliness of the power (no spikes, no high frequency "fuzz" - just pure DC at it's best.

Steve

Happy new year!

NiHaoMike · 01-02-19, 06:01 PM

Find a used UPS that takes a single 12V battery and just connect it.
Upgrade your UPS! (with some car batteries...)

pinballlooking · 01-02-19, 07:08 PM

Quote:

Originally Posted by NiHaoMike

Find a used UPS that takes a single 12V battery and just connect it.
Upgrade your UPS! (with some car batteries...)

I really like this idea a have a jetski AMG battery that would be great for this. I also have a UPS that has a bad battery. It is 12 volts so I think the two should work together.

randen · 01-05-19, 12:29 PM

A starting battery is just that. Was designed and tailored for just that. Put it on a buy and sell and use the money for other things. There are other things at play here that will render the battery useless to anyone and affecting its value to someone that needs a proper starting battery

It seems a lack of a quick discharge followed by a complete charge is not unlike exercise to extend the life. Sitting around and self discharging with the odd recharge is highly detrimental to a reasonable battery longevity

Randen

PS an investment in lithium with a battery management system is absolutely golden for any energy necessary experiment or toy. Lead acid is an absolute waste of time!!! Like screwing around with a film camera!!

oil pan 4 · 01-06-19, 12:19 AM

Keep it as a spare.

Piwoslaw · 02-02-22, 11:02 AM

Update - I bought a small inverter as a backup in case of blackouts.

I checked that the battery is still in good enough shape to power the refridgerator or heating system's pump and electronics for at least 4 hours.

12-30-18, 06:58 AM	#1
Piwoslaw Super Moderator Join Date: May 2009 Location: Warsaw, Poland Posts: 964 Thanks: 189 Thanked 111 Times in 87 Posts	What to do with a lead-acid car battery? I recently bought a new car, but it came with a cheap, undersized battery. For the engine Start-Stop function to work, I had to get a larger AGM battery. Now I have the old one as a spare. What can I use a 12V, 510A, 62Ah lead-acid battery for? I could keep it in the car, wired parallel, and delete the alternator, but the alternator doubles as a starter. And the ECU already turns off the alt field when the battery is topped off. I would love to use it to catch solar or wind, but our house is shaded year-round under tall trees. I could charge it at off-peak hours and power the house at peak hours, but our utility does not offer such a tariff, only flat rate. I could just leave it in the garage, topping it off every weekend with a trickle charger, and use it for testing random electronics projects, but that seems like a waste of a nearly new battery. Any other ideas? EDIT: One more idea would be some kind of e-assist project for a bicycle or bike trailer. __________________ Ecorenovation - the bottomless piggy bank that tries to tame the energy hog. Last edited by Piwoslaw; 12-31-18 at 04:27 AM..

01-01-19, 04:21 PM	#2
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Unfortunately, a starting battery isn't really all that useful. You can't deeply discharge it without significantly reducing the life of the battery. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

01-02-19, 04:37 AM	#3
stevehull Steve Hull Join Date: Dec 2012 Location: hilly, tree covered Arcadia, OK USA Posts: 826 Thanks: 241 Thanked 165 Times in 123 Posts	I use batteries like this for my electronic work. I do fuse it, but what you have is a virtually unlimited current source at a voltage that never changes. For + - ground supply, I hook up two batteries in series and now have a ground in the middle with a + and - 12 volt supply. FAR better than commercial power supplies - and the price is right. Some solid state stuff, especially analog, wants a very stable power supply. Bread boarding and prototype with the above configuration makes it a LOT easier as I don't have to be concerned with the stability and cleanliness of the power (no spikes, no high frequency "fuzz" - just pure DC at it's best. Steve Happy new year! __________________ consulting on geothermal heating/cooling & rational energy use since 1990 Last edited by stevehull; 01-02-19 at 04:41 AM.. Reason: clarity

01-02-19, 06:01 PM	#4
NiHaoMike Supreme EcoRenovator Join Date: Oct 2008 Location: Austin, TX Posts: 1,154 Thanks: 14 Thanked 257 Times in 241 Posts	Find a used UPS that takes a single 12V battery and just connect it. Upgrade your UPS! (with some car batteries...) __________________ To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her...

02-02-22, 11:02 AM	#8
Piwoslaw Super Moderator Join Date: May 2009 Location: Warsaw, Poland Posts: 964 Thanks: 189 Thanked 111 Times in 87 Posts	Update - I bought a small inverter as a backup in case of blackouts. I checked that the battery is still in good enough shape to power the refridgerator or heating system's pump and electronics for at least 4 hours. __________________ Ecorenovation - the bottomless piggy bank that tries to tame the energy hog.

01-05-19, 12:29 PM	#6
randen Uber EcoRenovator Join Date: Apr 2011 Location: Strathroy Ontario Canada Posts: 657 Thanks: 9 Thanked 191 Times in 129 Posts	A starting battery is just that. Was designed and tailored for just that. Put it on a buy and sell and use the money for other things. There are other things at play here that will render the battery useless to anyone and affecting its value to someone that needs a proper starting battery It seems a lack of a quick discharge followed by a complete charge is not unlike exercise to extend the life. Sitting around and self discharging with the odd recharge is highly detrimental to a reasonable battery longevity Randen PS an investment in lithium with a battery management system is absolutely golden for any energy necessary experiment or toy. Lead acid is an absolute waste of time!!! Like screwing around with a film camera!!

01-06-19, 12:19 AM	#7
oil pan 4 Land owner Join Date: Nov 2012 Location: NM Posts: 1,026 Thanks: 12 Thanked 127 Times in 107 Posts	Keep it as a spare.