SLA Battery lifespan/capacity

[RTLSHIP]

I have four. 36v 12ah battery packs that I use, along with a lifepo4 pack, on my 2 electric bikes. The yellow indicates
empty or low battery. It comes at 37.2 volts for one battery pack and and doesn't typically go yellow on other packs until
36.5 volts
Also, one of my battery backs is Silicone type Greensaver battery; the yellow low light does come on until 35 volts for this pack. Both bikes are Wilderness Energy types. How does the thumb throttle/controller determine when to go yellow?
Also, all of my battery packs remain fully charged at approx 38.4 volts or more when sitting. How can I determine lifespan?

 

[fifthmass]

It's hard to give a specific answer but in general SLA's have a cycle life of between 100-200 cycle with full discharge for average quality batteries. This assumes that you PROMPTLY put them on recharge as soon as you drain them. Keeping SLA's in a flat condition for even a few hours can cause some damage to them. Batteries intended for EV use may be good for 300-500 deep cycles. Discharging less than the full capacity can dramatically increase cycle life.

With regards to capacity I can get 324 watt hours out of a nominal 48 volt 10 ah SLA pack (324/480) = 0.675 (67.5%) usable capacity (which is pretty good for EV service).

Hope this answers your questions.

Regards,
Bill

 

[RTLSHIP]

thanks fifthmath. I read some of those things before. I guess a multimeter isn't helpful in determing the "age" of a battery.
I don't go below the nominal 36v and do quickly recharge.