how long?

[dundeebarnbuggy]

My math is a shaky on this. My batts are trojan "black box", 156ah, 6x8v and my lighting draws 3.7 amps from them. How long could I run the lights until they needed a recharge? [the setup with the lightbar will make a great worklight for temporary or emergency night jobs on the farm.

[Kashmir]

Do it the easy way and get an accessory battery and put in the bagwell for lights and accessories.
Then you won't use up any of your battery pack.

[dundeebarnbuggy]

With a draw of 3.7a why would I want to carry an extra 50+ pounds around and have to charge the PIA. The motor draws between 80 to90 amps on level ground, over a hundred going uphill. Don't think 3.7a is going to hurt my range much. Just wondered how many hours/days the pack would run the lights by themselves.

[Kashmir]

suit yourself.
one of the first things i did was add a battery for accessories.
LED lights, stereo and USB ports.
Don't draw a lot, but the way I see it, less drain = more battery life.
I'd rather replace a single battery every five years and get maybe an extra year out of my pack.

[klanel]

Dundee,

Taking your amp hour x 6 batts, I come up with 252.972973 hours if you are drawing off all 6. Of course if the amp hour rating is untill totally discharged, that would mean dead which you wouldn't ever want to do. But either way it should operate a long time. Just remembered the freezing cold you have so I would imagine the amp hour rating is much lower during that time.

[dundeebarnbuggy]

Thank you!!! And yes the ah is significantly reduced right now! But, haven't been bitten by a mosquito in weeks!

[klanel]

Are your lights 12v and are you using a dc-dc reducer from the 48 pack voltage? If so assuming a high efficiency reducer, you will be drawing less than 1 amp at 48v. So you could just total up your total amp hours to get the number of hours, in theory 936 hours. That is using all batteries, and that the amperage you measured was at 12v dc.

[dundeebarnbuggy]

The reducer is drawing 3.7amps from the pack [48v]. I have a standard light kit, [filament headlights, and led taillights and marker lights], and a 90w [actually draws 73w] light bar. Reducer [that came with the cart ] is 200w. Figure that is just about enough for it as the lights add up to 165w.

[Sergio]

I am not sure how You are calculating those hours.

A battery rating of 156Ah means a 7.8 amps load for 20 hours.

A load of 3.7 amps would totally discharge the batteries in about 40 hours.

If You ran the lights for 10 hours, you would have used 37Ah or about 24% of your battery pack capacity.

[dundeebarnbuggy]

Thank you!!! So if I ran the lights 20hours I would be at 48% discharge, right? Not like it is ever gonna happen, but they could run all night if need be. Cool. [I like overkill] Might really come in handy during planting if we are running all night to stay ahead of the weather, so see properly while filling the planter. Tractor lights are good but not so much behind the machine where you are when filling.