|How far can
I run these deep cycle AGM batteries down to?|
Can I monitor the battery voltage to get an idea about the DOD?
Do you have any larger Ah capacity in stock?
Can I wire two or more 12V95Ah(125Ah) batteries in parallel?
Why would I want two or more batteries?
Can I use your AGM batteries for cranking, what's their CCA rating?
Can I use your AGM batteries in a 24V system?
What sort of charger do you recommend?
I've got some questions, what's your email address or phone number?
|BV95-12 data sheet (153kB pdf)|
|Q: How far can I run these 95Ah batteries down to?||This depends on what cycle life you want out of your brand new battery.
BV AGM deep cycle series offer approximately 250 cycles @ 100% DOD (depth of discharge), 500 cycles @ 50% DOD and 1250 cycles @ 30% DOD.
The sweet spot is probably around 80% DOD.
Example: say you've got a load connected to your battery which draws 5 amps. Since 80% of 95Ah equals 76Ah, your load can draw current for 76Ah/5A equals a bit over 15 hours.
You can easily double this time by wiring two of these 95Ah batteries in parallel.
Note that this simple calculation is only true for loads, smaller than 6 amps (or 12 in case of two batteries in parallel).
For heavier load currents, some battery capacity derating is in order, as in the example below.
|Q: Can I monitor the battery voltage to get an idea about the DOD?||Yes,
you can (and should). Do a load budget first:
Say you have some lights, a fan, a fridge and a TV, all drawing current at the same time.
You're drawing like, 3A plus 4A plus 3A (fridge time averaged) plus 6A equals 16A of combined load current.
Now pull up the discharge table and locate the row for '1.75V' and start to interpolate.
You can use the formula below in which I2 and t2 are the current and time in the column immediately to the right of your load current Iload:
run time t=t2-((t2-t1)*(Iload-I2)/(I1-I2))
For our example, find the closest values to 16A which are 20.7 and 12.2, so I1= 20.7A, I2=12.2A, and t1=4h, t2=8h.
Plug these values into the formula and the resulting run time equals 6.2 hours.
But remember this would bring your battery to 100% of DOD, and we only want it to go down to 80%, so subtract 20% from 6hrs and the result is ~5 hours.
Because this battery is 95Ah, subtract another 5%, resulting in a 'run time' of 4.7 hours.
If more 'run time' is required, you can easily expect double this time by wiring two 95Ah batteries in parallel.
You'll actually get more than twice the 'run time' by doubling up, due to the Peukert effect, ~11 hours in this example.
Remember, the limit for the cutoff terminal voltage is 10.5V.
|Q: Do you have any larger Ah capacity in
at this stage, but you can easily double up - just read on.
|Q: Can I wire two or more 12V95Ah batteries in parallel?||Yes.
By doing so, you effectively end up having one large 12V battery. You
can leave them permanently wired up this way, for discharging
well as for charging.
The 12V charger only 'sees' one big battery. More on this under 'what sort of charger do you recommend'.
|Q: Why would I want two or more 12V95Ah batteries?||Compared
to only one large capacity battery, you gain greater fitting
flexibility since the bulky volume of one big 190Ah battery is now
split in half.
There is the important fact of twice the charge acceptance rate, meaning you can put twice as much energy (Ah) back into the battery, in any given amount of time.
E.g. if you use your car alternator for charging, the full 50A charge current made available can be absorbed by two 95(125)Ah batteries. If you only had one battery with a maximum 25(30)A charge current acceptance, your engine needs to be run longer, and there'll need to be some form of inrush current limitation, especially if the alternator output rises for the first few minutes (modern ECU controlled units).
No need to worry, if you connect two or more BV95(125) in parallel.
The max available starting current increases with the number of batteries wired in parallel. I recommend one battery per 2kW of starter motor power (typical for cars and small trucks). For larger engine cranking (big 4WD Diesels, bulldozer, heavy construction machinery, big marine Diesels), add one battery in parallell for each additional 2kW of starter motor power.
Save shipping money AND your back, by keeping the weight down (separate batteries only weigh 29 kg each). If there was only one 190Ah battery weighing in at almost 60 kg plus weight of packaging (skid or crate mount mandatory), couriers most definitely would charge extra for lifting gear.
|Q: Can I use your AGM batteries for cranking, what's their CCA rating?||Yes, you can!|
Car and 4WD starter motors have an internal resistance which limits the maximum starting current to 300~500 amps.
With ambient temperatures coming down, the cranking current increases due to higher engine oil viscosity.
Our BV95-12 AGM deep cycle batteries, when fully charged, are capable of supplying cranking current under above zero temperature conditions, for several minutes.
During the cooler months, two batteries wired in parallel give better performance.
What's more, our batteries feature solid lead bar terminals which allow for secure nut 'n bolt clamping, stainless are supplied with our batteries. These terminals have only half the contact resistance of some other designs (threaded screw in terminal post). Thus, they are better suited to high current applications due to less voltage drop at the battery terminals.
In a nut shell, due to the deep cycle desing, our batteries are not rated in CCA, but can be used for cranking in above zero tmperature conditions.
One word of caution: any battery will have a reduced service life of 40% per 10 degrees of temperature increase. Therefore, it's advisable to mount the battery in a cool spot (away from the hot radiator airflow, and shielded from the exhaust manifold).
For better heat and vibration resistance select our spiral wound pure lead/tin AGM battery.
|Q: Can I use your AGM batteries in a 24V system?||Yes you can. Note our recommendations on 24V battery charging.|
|Q: What sort of charger do you
'intelligent' three stage charger with a setting for AGM battery, as
long as the charger is rated between 6~25A.
E.g. if you have two 12V95Ah wired in parallel, your AGM charger would have to be capable of delivering a minimum of 12 A, and must not exceed 50A.
Our top of the range quality precision charger (made by Taiwan based WAECO DOMETIC OEM charger supplier) is most suitable for charging one and up to four BV95-12 batteries.
Check the following recommended features when comparing battery chargers:
Using an ordinary 24V battery charger (even if designed for AGM batteries) is NOT the best thing to do. Find out why, by emailing us on
|This is an important bit, I'd like you to read first.||AGM
VRLA batteries can be operated in any position. They last at least 2 to 3
times longer than ordinary 'sealed maintenance free batteries'.|
You cannot operate an ordinary 'sealed maintenance free battery' in any position, because the reality is, they are not 'sealed' at all. They have hidden vents through which the liquid electrolyte would spill! And the plates inside would be taken out of submersion which damages the battery very quickly if you'd draw any amount of current in this position.
These batteries cannot be shipped by courier or posted because they're classified
"dangerous goods" for a very good reason.
Sellers calling these batteries 'sealed' are grossly misleading their customers.
In contrast, the more costly to manufacture and long lasting VRLA AGM battery has the following benefits:
Flooded designs suffer from an effect called 'active material shedding'.
This material is held in place by the surrounding grid structure. Under certain operating conditions, this material can be shed, meaning it just sinks to the bottom of the container where it cannot be recovered through any means of charging.
In AGM designs this can't happen due to the tightly packed layers of glass matting between the plates.
Beware of 'maintenance free deep cycle batteries' which are not specified VRLA AGM or gel.
These are ordinary flooded lead calcium batteries which are worse than their non sealed cousins because their electrolyte level cannot be topped up with water.
The only purpose to produce such a battery is, to maximise profits by reducing the
manufacturing costs (no threaded openings with seals and caps on each cell).
And at the same time dodgy sellers use the notion 'sealed' to imply the advantages of a true VRLA battery which is a lot more expensive to produce and has the above mentioned benefits.
'Maintenance free' is a total misnomer as such batteries should be called 'non serviceable'.
Non VRLA 'sealed maintenance free deep cycle' batteries are the worst of them all since these batteries do not have any means of recombining hydrogen and oxygen which are produced during the charging process - no matter how well controlled the charging takes place. They lose electrolyte, through their vents. And this loss of electrolyte cannot be compensated by topping off, because the manufacturer has been cutting corners purely for the sake of increasing profits.
A very short battery life time is the result.
And the seller who adds the 'deep cycle' bit to the ordinary 'maintenance free', tries to screw you a second time around because any flooded battery rated in CCA or CA is designed for cranking, and as such is exactly the opposite of a deep cycle design. You can't just add a 'deep cycle' component to a thin plate starter battery - this is utter nonsense designed to make a quick profit from unsuspecting buyers.
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