Lithium batteries online

[Newcastle George]

From Battery Stuff.com

"AGM Batteries outsell Gel Cell by at least a 100 to 1. AGM is preferred when a high burst of amps may be required. In most cases recharge can be accomplished by using a good quality standard battery charger or engine alternator. The life expectancy; measured as cycle life or years remains excellent in most AGM batteries if the batteries are not discharged more than 60% between recharge. There are some AGM batteries we sell that offer excellent 80%+ deep cycle abilities.

Battery Tender Plus Gel ProfileGel Cell Batteries are typically a bit more costly and do not offer the same power capacity as do the same physical size AGM battery. The Gel Cell Battery excels in slow discharge rates and slightly higher ambient operating temperatures. One big issue with Gel Batteries that must be addressing is the GEL CHARGE PROFILE. Gel Cell Batteries must be recharged correctly or the battery will suffer premature failure. The battery charger being used to recharge the battery(s) must be designed or adjustable for Gel Cell Batteries. If you are using an alternator to recharge a true Gel Cell a special regulator must be installed."

George

[Newcastle George]

In order to check the Ah capacity of my new 2 x 12V (24V in series) 300Ah AGMs am I correct in thinking that a load of 15A over a 20hour period with an end voltage of 10.8 should do the job? My aim is to check that the batteries that I paid for are what I paid for.

George

[T1 Terry]

In order to check the Ah capacity of my new 2 x 12V (24V in series) 300Ah AGMs am I correct in thinking that a load of 15A over a 20hour period with an end voltage of 10.8 should do the job? My aim is to check that the batteries that I paid for are what I paid for.

George

15 amps @ 24v till the voltage in each battery or one of the batteries drops to 12v while still under load. This should not happen in under 10 hrs and represents 50% capacity. If you don't get the 10 hrs, recharge each battery @ 14.4v until the current flow in drops to 5 amps, drop the voltage to 14v and leave it charging at that for 2 hrs, it should drop to 1 amp or less. If it doesn't, the battery wasn't fully charged at the 14.4v stage, possibly the charging current was a bit high early on and the battery got hot. Leave the battery charging at 14v for another 2 hrs and recheck the current flow.
Once both batteries have reached this 14v charge with 1 amp or less charging current, let them both sit for an hr, then repeat the 15 amp load test and see if you get 10 hrs before either battery drops below 12v while the 15 amp load is still applied.

Another quick and easy test, what does the battery weigh, 100Ah @ 12v weighs between 30kg and 32kg, so does the battery weight between 90kgs and 96kgs? They don't make light weight lead and that is how much lead is required to hold 300Ah @ 12v nom. under a C20 load.

T1 Terry

[Newcastle George]

Well Terry, at 74kg they don't pass the weight test. I will perform your current test when I can find the correct load. Just as well I paid via Paypal.

They did fit the hole exactly

These are the specs as supplied.

300ah.jpg

George

[jon_d]

George,

from memory, they are the same size (mm) as mine. Mine are 250ah.

Which equates to about the same a/h using the weight calculation derived from the Fullriver 105A/H / 30.2 kilo ratio.

jd

[Newcastle George]

Batteries fully charged and rested, Test began midday with current draw exactly 15A according to Victron BMV2

I saw 330AH AGMs advertised on this website https://www.aussiebatteries.com.au/batt ... le-battery with exactly the same size and weight.

George

[BernieQ2]

That link isn't working my laptop George.
Bernie.

[Newcastle George]

Fixed now Bernie.

George

[BernieQ2]

Ta mate.
Bernie.

[Newcastle George]

Results are in: I may need a battery balancer.

Click to enlarge

Capacity Test.JPG

George