# Battery for man lift?

Registered Users Posts: 13
Hey guys. Back again.

I'm trying to figure out what kind / how much battery I need - to supply 1kW of power for ~30 seconds, 4-6 times a day. I'm trying to power a 12V winch that will be used in a man lift to my balcony, it's supposed to use about 1 hp.

AGM? Maybe just a non deep cycle car battery to get the "cranking amps"?

• Solar Expert Posts: 3,123 ✭✭✭✭
Re: Battery for man lift?
Jasonzebra wrote: »
Hey guys. Back again.

I'm trying to figure out what kind / how much battery I need - to supply 1kW of power for ~30 seconds, 4-6 times a day. I'm trying to power a 12V winch that will be used in a man lift to my balcony, it's supposed to use about 1 hp.

AGM? Maybe just a non deep cycle car battery to get the "cranking amps"?

Can you confirm that the winch motor really is drawing about 80 amps or more? If so, then an AGM battery might be ideal as they have the capability to deliver up to C or even 4*C in current for a short time. Based on that a 100 AH AGM battery should be more than able to handle it.

Looking at it from another angle, 80 amps for 30 seconds is only 80/120 = .67 AH, so the depth of discharge would not be all that bad for either FLA or AGM.

An FLA deep cycle battery would need to be 800 AH or more to handle that current without too much voltage drop.
A cranking type battery would have the problem that using it 4-6 times per day might run you out of battery cycle life in a few months even though you are doing a shallow discharge. A comparison as a reality check on the feasibility would be whether you could get away with running a winch on a 4-wheeler with the engine off with that kind of duty cycle.
SMA SB 3000, old BP panels.
• Solar Expert Posts: 3,009 ✭✭✭✭
Re: Battery for man lift?

The wattage / current required by the winch will be directly related to the loads it is being asked to lift. The heavier the man, the greater the load on the battery. Likewise, the lighter the man, the lighter the electrical load.
• Solar Expert Posts: 10,300 ✭✭✭✭
Re: Battery for man lift?

the agm type battery can take heavy usages with less chance of damage to the battery, but that voltage will still be sucked downward. you will most likely need more than 100ah in capacity to maintain the voltage needed by the winch. 1000w is 83.3a and is a sizable load.

i know this is a dumb question, but don't you have stairs to the balcony?
• Registered Users Posts: 13
Re: Battery for man lift?
niel wrote: »
the agm type battery can take heavy usages with less chance of damage to the battery, but that voltage will still be sucked downward. you will most likely need more than 100ah in capacity to maintain the voltage needed by the winch. 1000w is 83.3a and is a sizable load.

i know this is a dumb question, but don't you have stairs to the balcony?

no stairs. It's gotta be a man lift, nothing else will suffice for my lair. I may need to invest in a larger battery...

300W of solar, tristar mppt 60A controller, and now a 150AH agm batt
• Solar Expert Posts: 5,134 ✭✭✭✭
Re: Battery for man lift?

You need a counter balance to reduce the load, figure the lightest person using the lift and place a weight equal to that on the other end of a cable, now you've reduced the work load significantly. Lots of safety things, must be well mounted to handle many times the load, I think ladders are rated at 3x the capacity for a dynamic load, or a 200 lbs rated ladder will safely handle a static load of 600 lbs at it's weakest point. Multiple twists around the capstin(?) will help with friction, or you can winch up one end of the balanced cable, but it'll need your weight to go back down...
Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
• Solar Expert Posts: 10,300 ✭✭✭✭
Re: Battery for man lift?

".....place a weight equal to that on the other end of a cable....."

excellent idea.8)

even if he doesn't have a "other end of a cable" he can put one in on a pulley. some means will be needed to keep the lift from going up though after you get off on the lower level as that weight will put it at the top again if not locked down.

in fact several pulleys could be used to allow a smaller weight to do more work and the weight can also be put elsewhere away from the lift if he desires.
• Solar Expert Posts: 5,183 ✭✭✭✭
Re: Battery for man lift?

the old 'dumbwaiter ' apparatus comes to mind...

KID #51B  4s 140W to 24V 900Ah C&D AGM
CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM
Cotek ST1500W 24V Inverter,OmniCharge 3024,
2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep