testing a dead battery

[faramog]

Any advice folks ?

Have a 90AH battery. I have run it on my ssg (3 coil of which 2 are trifilar). Initial charging had an upper voltage of around 11V. Now consistently up at 13.7 on charge. The problem is that after 100+ hours running generally no more than 15 hours without an 8 hour break, the rest voltage stubbornly refuses to raise above circa 10.7 V.

The other one is fully energised. After a 'normal' charge it held a 30w load for 15 mins. After SSG, it rests at 12.8 and held a 60 W load no problem.

Somehow, it does not feel like sulphation - the power I have put in ?

Thanks
G

[Bit's-n-Bytes]

Any advice folks ?

Have a 90AH battery. I have run it on my ssg (3 coil of which 2 are trifilar). Initial charging had an upper voltage of around 11V. Now consistently up at 13.7 on charge. The problem is that after 100+ hours running generally no more than 15 hours without an 8 hour break, the rest voltage stubbornly refuses to raise above circa 10.7 V.

The other one is fully energised. After a 'normal' charge it held a 30w load for 15 mins. After SSG, it rests at 12.8 and held a 60 W load no problem.

Somehow, it does not feel like sulphation - the power I have put in ?

Thanks
G

How far did you allow the batt to discharge with the load? It appears this is sulfated.

Jeff

[faramog]

I didn't. It arrived dead. I got two dead 90AH batteried. One is well on the way to being fully restored. the other has had twice the charging and moved no-where.

I even stuck it on a conventional charger for a couple of hours to see what happened... nothing .. same !!

[Bit's-n-Bytes]

I didn't. It arrived dead. I got two dead 90AH batteried. One is well on the way to being fully restored. the other has had twice the charging and moved no-where.

I even stuck it on a conventional charger for a couple of hours to see what happened... nothing .. same !!

Your best chance of rejuvinating this batt is to load it down to 10.5, then charge to 13.5 - 15volts. Repeat this process at least three times and see if you get any gains. If you do, continue, if not, it's toast.

Jeff

[theremart]

Won't budge about 10.7

may have a dead / shorted cell.

If you can open the caps, get yourself a coat hanger and cut it up and measure the voltage between the cells ( cap to cap ). You may find one that is dead.
If you find one that is dead, I have found it is best to swap the core at the local battery shop for another one that has better chances of being revived.

Often batteries have broken plates and part falls inbetween shorting the cell. thus you can't get above 10.5 V.

[theremart]

One other thing.

I would get myself an inverter with an alarm, and I would time how long it took for the inverter to sqeal when I discharged the battery after each charge. If the battery improved after 5 cycles I would keep at it. With low amperage input or few transistors, the improvement is very slow.

[faramog]

Thanks all (so far). Not sure what coat hanger is for ?

It does not hold any charge ending up circa 10.7 (which is very dead).

When its light tomorrow I will see if anything opens (must remember to find my goggles and gloves !!)

The good news (and please no OU tosh - not gonna get it directly form an SSG with bad tuning). Other battery started at 12.81. Measured load for 1 hr 10 mins of 0.0657 units, charged via source for 30 mins with a power of 0.0104 units and ended up back at 12.77 (COP apparently 6 ish). At least this battery is starting to perform

[theremart]

RE: coat hanger.

Thanks all (so far). Not sure what coat hanger is for ?

It does not hold any charge ending up circa 10.7 (which is very dead).

When its light tomorrow I will see if anything opens (must remember to find my goggles and gloves !!)

The good news (and please no OU tosh - not gonna get it directly form an SSG with bad tuning). Other battery started at 12.81. Measured load for 1 hr 10 mins of 0.0657 units, charged via source for 30 mins with a power of 0.0104 units and ended up back at 12.77 (COP apparently 6 ish). At least this battery is starting to perform

The coat hanger you can use to put into each cell to measure the voltage, instead of eating up your probes on your multimeter.