Is This Battery Charging Possible

The whole idea of the battery is that it acts as an energy store for when it is needed. If the recharge rate were to be the same as the discharge rate, then the battery could then be eliminated from the equipment without affecting its performance.

Hi Idea is that since we have huge power outage, as when grid power available battery should be charged at the same rate as discharge. This helps to have much required power from battary when grid not available.

Thanks

If your power outages are frequent and you need the batteries recharged as fast as possible, you want a "smart" charging system. This charger will control peak charging current, end-of-charge voltage, and supply the proper maintenance charge for SLA batteries. It will also maximize the LIFE of your batteries. Based on your numbers, best recharge time will be approximately 5 hours for batteries that need a full charge.

You can build a "simple" charging circuit using a few large diodes, a power resistor, and possibly a large relay. Charging will take 2 to 5 times longer (10-24 hours). If you don't design this circuit carefully, the battery life could be severely reduced.

If you truly need a battery backup that can be recharged as fast as it is discharged, you will need to find different batteries.

I think you can do one of the 2 things: Use batteries with higher amperage ratings or build a paraller powder supply with additional batteries for the required voltage, when power is on both the powerpacks get charged and power is off, you will be using only one half of the available amperage to run your motors and will have enough spare capacity available

vshwn7@aol.com

If you use and intelligent charger (already mentioned here somewhere), one that you can sett to charge ONLY up to say 52.8 volts at 20 amps, you will never overcharge the batteries, in fact they will be very slightly undercharged, but the motor will also be supplied fully. If the mains fails, the batteries will take over the load for about 2 hours if in a good condition.....

Basically, this is similar to what I do with my caravan battery (only 12 volts though!)

May i suggest that leisure batteries will give a far longer life for such a system, though they cost a bit more......do not use car batteries unless you have already got them, they will not like this system much!!! A short life is programmed for them already.....

Guest you did not state if your SLA batteries are Gel or AGM. Big difference in how fast they can recharge.

AGM can stand a much faster charge rate in some cases well above the 20% rate you have seen mentioned somewhere.

You do need an intelligent charger and one that is specifcally optimized for the specific chemsitry of your kind of battery. 17 amps rate for a 40 A-H battery rating is not too bad. Just be sure to keep the batteries cool. We have had good success with liquid cooling of critical battery install.

The circular OPTIMA and the GATES batteries are best for this fast charging. Thin plate technology batteries are also quite good. I have charged these at 50% and even 100%, but it does reduce number of life cycles drastically. It is all a question of how critical the application is.

My friend who was involved in prototyping a chain gun for boat installations used GATES Cyclotron batteries at a discharge rate of 450 Amps/ Hr in 15 minute and the requirement was for recharge iat the same rate. Battery life was only 50 missions but so what? These guns used up their ammo in less than 3 minutes at rapid firing rate. The ammo was more expensive than the replacement batteries.

Many of the above comments are good, but as I see it: Why not just use the grid to run the motor load via a drop out relay to transfer power over to the batteries? Should take only a few milliseconds, depending on the relay selected. Meanwhile, the batteries would be on charge.

All that you need is a float charger. The system works like an UPS. The battery is on float when the grid power is on and does not supply current nor is it charged. The charger must have a provision to control the charging rate when the motor is not running. Not very difficult. bioramani

What you are describing is done everyday in about every cell phone site on earth. It uses inverting Switching power supplies these are cheap and in ready demand. Ask anyone you might know in the Cell phone business about them.