Flooded lead acid usage compared to AGM

Van Living Forum

Help Support Van Living Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
A properly designed deep cycle FLA can be taken down to 20%. You can theoretically flatten a FLA once a week for 9.61 years to get 500 cycles out of it (500 / 52). I have had up to 7.5 years out of good quality deep cycle FLAs in abusive use. If you go FLA, keep’em charged.

Energy density is generally lower in FLA so more weight for labeled capacity, when compared to AGM. Over charged FLA fume lots so venting is important and no naked flame. Standard charging also causes fumes and many a battery has exploded due to a close naked flame or spark. FLA benefits from a regular overcharge as a prevention against sulphation. Overcharging is often called “boiling” and 10 minutes of visible bubbles is sufficient. You can top up electrolyte lost to overcharging/fuming. FLA gives you access to the electrolyte so a hydrometer can be used to check SOC without interference from from surface charge considerations when measuring SOC as a voltage level. Don’t really recommend this but you can drain, flush, and replenish electrolyte about half way through projected life.

Keeping any LA battery fully charged ensures best life.
 
Regularly taking even a $5000 FLA bank down to 20% SoC will give you a **very small** fraction of cycle lifetime compared to 50%. Staying in the top 20% will give many times longer, but the ratio won't be nearly as steep as the first one.

Even with Rolls / Surrette, you will never get 500 cycles going down to zero, 10.5 V

Yet cared for properly, they can often last 12-15 years of fulltime use coddled, pushing to say 70% SoH State of Health as your definition of EoL End of Life.

Bubbling and offgassing is a normal part of proper charging, 100% Full is spec'd by measuring trailing amps while holding Absorb volts, only dropping to Float after endAmps is reached.

If the battery box is well ventilated as it should be, there is no danger of fumes ignition.

Overcharging is harmful, by definition.

Mfg spec'd Equalizing protocols are used to preventing sulfation, more frequently in PSOC partial SoC abuse situations where you just can't get to Full at least a few days per week.

That is not overcharging if you properly follow the mfg specs for your battery, can require special equipment, should always be a manual process each battery done separately.
 
I've been using 2-Trojan T105's for 3 years which I paid $130 each. So far so good. I watch TV and run my heater blower all night and rarely get down to 50pct by morning. I'm not going to replace them when they are below 50pct on a regular basis but when my heater/lights stop working in the middle of the night

By way of comparison I used to spend $350-$500 a month on gas and electric. The only problem I face is how can I ever go back
 
Top