Voltage required to start a Perkins 4-108

[CoCoKnots]

I just replaced the starter on my Perkins 4-108. They told me it was fried because I tried starting it when the batteries were too low. Now that I have a new one in place along with new batteries, I would prefer not to repeat the error. The refrigeration is what pulled the batteries down in the first place... & it's doing it again. This morning they were at 10.07 volts from 12.6 just five days ago. I've been trying to charge them back up with my Honda 2000i Generator without much success. It did start yesterday with 11.2 volts... Don't want to try that again until I find out what my limits are. Thanks, Cal

[atoll]

you have to decide what is more important fridge or engine!
you can allways start the engine to charge the fridge batteries if you have a dedicated engine start battery,sounds like you need to work out your wiring and battery plan.
most likely you have damaged your batteries pulling them that low

[perchance]

You need a dedicated engine start battery no exceptions no ifs ands or buts.

[ranger58sb]

Originally Posted by CoCoKnots

I just replaced the starter on my Perkins 4-108. They told me it was fried because I tried starting it when the batteries were too low. Now that I have a new one in place along with new batteries, I would prefer not to repeat the error. The refrigeration is what pulled the batteries down in the first place... & it's doing it again. This morning they were at 10.07 volts from 12.6 just five days ago. I've been trying to charge them back up with my Honda 2000i Generator without much success. It did start yesterday with 11.2 volts... Don't want to try that again until I find out what my limits are. Thanks, Cal

Below about 12.2v is getting risky. How often are you trying to charge? Sounds like you need a combination of more battery (bigger banks), mix of separate house and starting battery(ies), more frequent charging, maybe parallel switching, etc.

You might say a few words about what your battery layout is like, now... and folks might be able to give more specific recommendations after that...

-Chris

[witzgall]

If your batteries are reading 10.07 volts, they are all but drained, or even worse, dead. I am going to hazard a guess that the batteries have been tortured by chronic under charging, and are toast. How old, what capacity, etc? I agree with the separate starter battery.
Chris

[Blue Stocking]

Originally Posted by perchance

You need a dedicated engine start battery no exceptions no ifs ands or buts.

+1 This cannot be emphasized too strongly.

[kentobin]

11.90 Vdc is considered 100% discharged without a load. 10.07 Vdc sounds like your battery probably has a shorted cell.

There's a lot of good battery information on the net and it appears you should google for some and start reading. A second opinion is good but you need your own too.