Recommendations for battery state of charge

[JohnnieB]

Originally Posted by Scobra1

I bought this one for my lithium upgrade. Easy to install, except for the precise round hole for the gauge. Easy to determine AH available by using batteries down to the low limit and then recharge. The meter shows AH put in batteries while on charge. You then set that as 100% SOC. The meter will be dead accurate from then on.

https://www.ebay.com/itm/Battery-Mon...0AAOSw3ppgUKPa

Only with a lithium battery pack. With Lead-Acid, it'll probably have to be reset to 100% after each charge.

The charging efficiency of lithium batteries is close to 100%, so the AH-in vs AH-out will stay in sync for many charge cycles.

On the other hand, Lead-Acid charge efficiency is only about 85%, so the meter will be up to about 15% off on the second charge cycle and up to about 30% on the second and so on. Making coulomb counting even more unpredictable for lead-acid batteries, their charging efficiency varies with make/model of battery and the battery temperature while charging.

[JB in PA]

Originally Posted by emoney

I bought this inexpensive, shut-based meter off Amazon and I really like it so far. IMHO, only way to get an accurate reading is using a shunt.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

This is a cool gauge for a seriously good price...thanks for linking this