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This question is an exact duplicate of:

I am planning on using a rechargeable lead acid battery for my tennis ball pitching machine. Is it feasible to hook them up to motors and run the motors until the battery is empty, and then come home and charge it (repeat this process nearly daily)? If so, what type of charger do I need? Any advice or product recommendation would be great. Thanks!

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marked as duplicate by SamGibson, PeterJ, Voltage Spike, Dave Tweed Oct 3 '17 at 11:59

This question was marked as an exact duplicate of an existing question.

  • \$\begingroup\$ No, do not run lead acid until it's 'out', that leads to a very short cycle life. Nickel chemistry is fine with that, if you really want to operate batteries without an end-point shut-off. \$\endgroup\$ – Neil_UK Oct 1 '17 at 12:42
  • \$\begingroup\$ How many Amps? Is it a new 50 Ah deep cycle battery ? 11.5V min \$\endgroup\$ – Sunnyskyguy EE75 Oct 1 '17 at 14:43
  • \$\begingroup\$ You'd need a lead acid battery charger: google, than some indicator. Simplest is to use a voltage indicator, below 11.9V you may stop and recharge. \$\endgroup\$ – Marko Buršič Oct 1 '17 at 14:44
  • \$\begingroup\$ It will work fine if you are able to avoid deep discharge of the battery. If the battery is sized generously it may last around 2 years. I recommend that you use a deep cycle AGM lead acid battery. The AGM batteries do not require maintenance and do not spill caustic liquid if the case ruptures. If you use a random car starter battery it probably won't last nearly as long, and it may spill acid if it tips over or cracks. \$\endgroup\$ – mkeith Oct 1 '17 at 18:01
  • \$\begingroup\$ A bit more specifications on the load and duty would also be a useful. \$\endgroup\$ – KalleMP Oct 2 '17 at 13:13
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If you are thinking normal "car" batteries, then you shouldn't discharge them below half their capacity. That may still be the cheapest way to get portable power, though.

Voltage is not a good indicator for state of charge for lead-acid batteries. You'd have to track total current.

Other battery technologies would be more suitable, or get something fully packaged so that you don't care what is inside. Any decent UPS, for example, will not allow discharge deep enough to cause significant damage to its battery.

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In addition to shortening lifetime of the lead acid battery as mentioned, any discharge down to 50% ill take longer to recharge. Most lead acid battery manufacturers would advise to not discharge below 70% for these reasons.

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