Battery Question

[MVH1]

I just bought a brand new Exide deep cycle battery and it will not charge above 75% on my battery/trickle charger. I did leave the battery hooked up for a couple of days after I returned which did drain it. I'm not sure if it drained it completely. I just can't believe that this could happen after one use. If anybody has any expertise in this area I would appreciate the advice. Thanks

[MEXICOWANDERER]

A hundred cycles is a substantial percentage of a flooded L/A battery's life. For critical applications we used to "burn in" new batteries. 14.8 volts constant until the cell started to bubble at more than one bubble per second. This rendered more than 95% CCA and reserve capability.

Please keep in mind, the power company usually feeds even a small battery manufacturer with 750 kw capability. Electricity is expensive. So manufacturers green and condition new batteries with as few kWh as possible.

"Cycling" a new battery is a better PR term than "For best results slow charge the battery several hours". Plaid suits, fluorescent ties, and Italian loafers write the hype.

[JamesJudasPries]

MEXICOWANDERER wrote:
"I would first assume"

Assume nothing unless you have money to burn.

Come on Mex, you're telling me that the first thing you would think of wouldn't be the slow 70mA charge is the reason the battery wont reach past the 75% indicator in a short time?

[HiTech]

They don't get full capacity until they are cycled, but they reach full state of charge, just a bit sooner.

Jim

[ryhed]

Aren't brand new batteries not supposed to achieve a full charge until a determined amount of charge cycles? I know golf cart batteries are that way. It takes around 100 recharges to reach max charge.

[MVH1]

You guys are great! It sounds like I am using the wrong charger type of charger and that my battery might be ok. I will look into using the other charger and I appreciate all the advice. Thanks!

[MEXICOWANDERER]

MEXICOWANDERER wrote:
"I would first assume"

Assume nothing unless you have money to burn. Did genuine battery shops disappear off the face of the earth when I wasn't looking?

Mark the wires according to the terminals. Remove the battery and take it to a rootin' tootin' battery shop and they will charge it, hydrometer test it and load test it. If the battery needs to be equalized they will do that too.

Batteries need to vacation fully charged. Trying to charge with a trickle charger would be like fighting a kitchen fire with a squirt gun. A discharged battery DOES NOT HAVE THE LUXURY OF WEEKS to recharge. Hard sulfation will form between start and finish and you will have doomed the battery.

If a trickle charger is all you have apart from the pseudo charger in the rig, you need some way to fully charge the battery. Easily. Fully. No guesswork. Many on this forum have a primary charger to raise voltage to a reasonable level then a mechanical charger to take over when the smart charger goes stupid in order to finish the job.

[MEXICOWANDERER]

"I would first assume"

Assume nothing unless you have money to burn. Did genuine battery shops disappear off the face of the earth when I wasn't looking?

Mark the wires according to the terminals. Remove the battery and take it to a rootin' tootin' battery shop and they will charge it, hydrometer test it and load test it. If the battery needs to be equalized they will do that too.

Batteries need to vacation fully charged. Trying to charge with a trickle charger would be like fighting a kitchen fire with a squirt gun. A discharged battery DOES NOT HAVE THE LUXURY OF WEEKS to recharge. Hard sulfation will form between start and finish and you will gave doomed he battery.

If a trickle charger is all you have apart from the pseudo charger in the rig, you need some way to fully charge the battery. Easily. Fully. No guesswork. Many on this forum have a primary charger to raise voltage to a reasonable level then a mechanical charger to take over when the smart charger goes stupid in order to finish the job.

[BFL13]

rtmcavoy wrote:

BFL13 wrote:
Ignore the bogus 75% reading on the charger and just take SG with an hydrometer to get the truth. Or else let the battery sit for a couple days disconnected (no wires at all) and then take the voltage.

There are voltage vs SOC charts (of course they are all different, so check here before believing any one such chart)

I am trying to get educated what is SG with hydrometer?

http://www.engineersedge.com/battery/specific_gravity_battery.htm

[JamesJudasPries]

Hi,

measuring SG means measuring specific gravity (also called relative density) of the battery electrolyte. This can only be done on a flooded wet cell battery, ie one that has vent caps. Basically, what happens is you take off the vent caps and use a hydrometer to measure the strength of acid/ state of charge in each cell (all 6) of the battery. The hydrometer draws some of the acid into its tube and you can see how much charge the battery has by looking at the floats on the hydrometer scale.

But really, I wouldn't bother with this quite yet. I would first assume that the charge rate on the charger you speak of is way too slow. I agree with the others on this forum. If you are sure your charger is 70 milliamps, ya it will take days maybe weeks to charge. You are better off with at least a 1.25a battery tender or something else with more current output.

[MVH1]

BFL13 wrote:
Ignore the bogus 75% reading on the charger and just take SG with an hydrometer to get the truth. Or else let the battery sit for a couple days disconnected (no wires at all) and then take the voltage.

There are voltage vs SOC charts (of course they are all different, so check here before believing any one such chart)

I am trying to get educated what is SG with hydrometer?

[RoyB]

Consider this Progressive Dynamics Brochure report on how long it takes to charge up a deep cycle battery.

"Progressive Dynamics ran this test on the amount of time it took a PD9155 (55-amp) converter/charger set to three different output voltages to recharge a 125 AH (Amp Hour) battery after it was fully discharged to 10.5-volts.

14.4-VOLTS (Boost Mode) – Returned the battery to 90% of full charge in approximately 3-hours. The battery reached full charge in approximately 11 hours.

13.6-VOLTS (Normal Mode) – Required 40-hours to return the battery to 90% of full charge and 78-hours to reach full charge.

13.2-VOLTS (Storage Mode) – Required 60-hours to return the battery to 90% of full charge and 100-hours to reach full charge."

Note Progressive Dynamics is using a 55-AMP DC source for power. I regularly charge my three GP24 deep cycle batteries using a 60-AMP power source when camping off the power grid with my on-board PD9260C Converter/charger being run by a 2KW Honda Generator and get similar results.

I use this DC VOLTS VERSES STATE OF CHARGE chart when I am camping off the power grid to get me somewhat close to state of charge I want to be at..


The rule of thumb passed among alot of battery types here on the forum is around 20AMP of available DC power is needed for each battery being charged.

Just food for thought here...
Roy ken

[wa8yxm]

Use a digital voltmeter or multi-meter and measure the voltage AT THE BATTERY TERMINALS.. Then look up the state of charge on any of the many SOC charts that have been posted to the forums.

Do not trust the wall display.

Some friends of mine do not think highly of Excide batteries.. can not argue with them.

[Canadian_Rainbi]

mena661 wrote:
Did you say 70 MILLI-amps? It'll take weeks for that battery to charge to full. You need a real charger.

Black and Decker VEC1093DBD

I make it closer to a month.

Assume a group 24 battery rated at 80 AH discharged to 50%: needs 40+ AH back in. 70mA+.07 Amps:

40 / .07 = 571.3 hours, or just about 24 days.

You need at least a 15 amp smart charger to almost reach the C-20 charge rate. It would charge very nicely with the B&D charger mentioned. The 20A setting would give you an initial charge rate rate of 25% of the AH capacity, or C-25 which that battery should handle just fine. Use the 10A rate if you aren't in a hurry.

[mena661]

Did you say 70 MILLI-amps? It'll take weeks for that battery to charge to full. You need a real charger.

Black and Decker VEC1093DBD