LVC and SLA battery pack abuse

[e-beach]

An old computer plug

A block of wood, some duct tape and a tie wrap or two and BING!

An instant dashboard for my temporary volt meter set up!

Now to get some real numbers.

When I started off today to go to my favorite beach, my SLA pack was fully charged at 39.9 volts. I mapped out the most direct way to where I wanted to go on Google Earth, turned on my temporary volt meter and away I went.

Warm enough to make me take my coat off today. 8)

The full trip down there and back (if you believe Google Earth) is 9.34 miles.

At the end of my ride the voltage in my pack read 36.3 volts.

During my ride, the lowest reading I got was 30.2 volts. That was at the end of my ride, with about a half mile left. I went full throttle to see if I could get any speed at the end of this ride and the voltage dipped to 30.2 until I started getting speed then went into the 32 to 33 volt range.

My battery back is 3-12 volt, 12 amp SLA’s in series.

So my questions are these…

Does it sound like I am abusing my SLA battery pack with this length of a ride?

If my controller isn’t cutting out at 30.2 volts, at what voltage does it cut out?

Any and all thoughts would be helpful.


(moderator edit: merged your duplicate posts in different forums. please only start one thread on a subject at a time.)

 

[e-beach]

An old computer plug

A block of wood, some duct tape and a tie wrap or two and BING!

An instant dashboard for my temporary volt meter set up!

Now to get some real numbers.

When I started off today to go to my favorite beach, my SLA pack was fully charged at 39.9 volts. I mapped out the most direct way to where I wanted to go on Google Earth, turned on my temporary volt meter and away I went.

Warm enough to make me take my coat off today. 8)

The full trip down there and back (if you believe Google Earth) is 9.34 miles.

At the end of my ride the voltage in my pack read 36.3 volts.

During my ride, the lowest reading I got was 30.2 volts. That was at the end of my ride, with about a half mile left. I went full throttle to see if I could get any speed at the end of this ride and the voltage dipped to 30.2 until I started getting speed then went into the 32 to 33 volt range.

My battery back is 3-12 volt, 12 amp SLA’s in series.

So my questions are these…

Does it sound like I am abusing my SLA battery pack with this length of a ride?

If my controller isn’t cutting out at 30.2 volts, at what voltage does it cut out?

Any and all thoughts would be helpful.

 

[ElectricEd]

Does it sound like I am abusing my SLA battery pack with this length of a ride?

Sure are. Divide by 3 and compare with a 12V battery. 10V is really giving it a hard time. If they are standard SLAs then you are killing them. Glass mat SLAs will cope a bit better. Either way, the battery life is reduced considerably by discharging below 65%. The best trick is to avoid SLAs because their performance is woeful and they are false economy. Bight the bullet and go Lithium if you can afford it. You'll be much better off in the long run.

If my controller isn’t cutting out at 30.2 volts, at what voltage does it cut out?

Can't say, it depends on the controller and wether it has a low voltage cutout. If it has and is set below 30 volts then that is getting too low.

 

[nechaus]

I could not be bothered reading everything because i was looking at the nice picture of the beach
Lovely picture


Umm LVC on sla, I would not go past 11.5 volts per 12 volt pack..
I feel like when i use sla, its always getting abused because the actual AMP HOURS are rated over a 20 hr period

10 ah pack you will be lucky to get 5 ah


My advice, get rid of them and go lipo or lifep04

 

[REdiculous]

If my controller isn’t cutting out at 30.2 volts, at what voltage does it cut out?

Try it and see?

 

[e-beach]

Sure are. Divide by 3 and compare with a 12V battery. 10V is really giving it a hard time. If it has and is set below 30 volts then that is getting too low.

Yea.....that is what I was thinking.... :?

On the other hand the SLA's were only for the purpose of getting me in the e-bike game so I will run them till they drop. After that LifePo4's here I come!

 

[e-beach]

I could not be bothered reading everything because i was looking at the nice picture of the beach
Lovely picture

Thank you! It is Santa Monica Beach, California, USA.

 

[e-beach]

(moderator edit: merged your duplicate posts in different forums. please only start one thread on a subject at a time.)

Thank you moderator for the merge. When I saw that I posted this in the wrong spot, I reposed in the e-bike section and then couldn't figure out how to delete the misplaced post.

 

[e-beach]

If my controller isn’t cutting out at 30.2 volts, at what voltage does it cut out?

Try it and see?

:| Guess I am going to need to..... Time to drive a long way along the sea shore.

 

[dogman dan]

If you want to have those sla's last, whack at least 30% of that distance in the future. Keep riding like that, and you might be advised to get that lifepo4 ordered today.

I did the same thing, sla's came with the kit. I barely managed to get 30 days out of them, till my first ping arrived. I was taking them down closer to 25v though.

 

[e-beach]

I was taking them down closer to 25v though.

Was that 25 volts under load or 25 volts after you finished your ride?

 

[dogman dan]

Under load, but as light a load as I could make it. I was riding 14 miles, and was likely to only get about 10 before the battery died. So I was riding till the controller cut out.