Remco 12V Battery?

I purchased a Lowrance Elite 3X and the Hobie III installation kit with the Remco rechargeable battery. Very nice and compact package. I'm wondering how many accessories can be run off this battery (Without going crazy with laptops and coffee makers) and how long a charge will last?

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2015 PA 12 OLIVE

The fully charged battery is rated for 9 AH or 9 amps delivered for a period = 1 hour.
If you add up the total DC current required to operate all of your electronics, its easy to determine approximately how long the battery will last before needing to be recharged.
As an example, if the total DC current = 2 amps, then the battery will last 9 AH / 2 AH = 4.5 hours of use.

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Dr.SteelheadCatcher
Warrenton, OR

However - I will add THEY(whomever they are) say you should never run your typical lead acid or AGM batteries below 1/2 capacity. If you drain them all the way it is possible they may not charge. I would calculate a buffer to be safe.

This is probably way more info than anyone wants...

As pa14naz mentioned, a lead-acid battery is much happier if you only use the top 50% of its charge. You can take it lower, but life is greatly reduced. Stay in the top half and you can get thousands of charge/use cycles. Use its full capacity and you may only get a couple hundred cycles. Note: "use its full capacity" does not mean "dead". If you run the battery until dead, it may never charge again. Even if it does it will be damaged and not work as well as before.

Of course in a recreational use setting, a couple hundred cycles may be fine - that might be a couple years life and these little AGMs will age and eventually die even if they are babied. Getting a large enough battery to stay in the top 50% adds a lot of weight.

Also be sure to recharge as soon as you can. The chemical process that supplies energy produces sulphate that covers the plates. If left too long it hardens and can't be undone, reducing capacity. A day or two should be fine, though the more deeply discharged the battery is the quicker the damage.

One more note, the capacity of a battery isn't as simple as dividing amp-hour rating by time. Most batteries are rated at a 20-hour discharge rate. This means a 9AH battery can supply 9AH of power, or 0.45A continuously, for 20 hours. You can draw higher current than that but the capacity of the battery drops. The higher the current the less AH you can get out of it. The converse is also true - if you draw less than 450mA you can get more than 9AH total. (The cause of this is called Peukert's law.) The battery manufacturers usually provide a chart on the data sheet for the battery that shows capacity vs current draw.

I don't know which specific model Hobie is providing and didn't find one listed as 9AH, but here's the datasheet for their 10AH version which does specify 9AH at the 5-hour rate (meaning you could draw 1.8A for 5 hours).
http://www.remcobattery.com/dbimages/do ... m12-10.pdf

Yes... I know way too much about batteries... I put a small off-grid solar power system together and it became yet another of my hobbies!

RandomJoe....as a retired EE, providing too much info, to a simple question can/may only confuse the non technical person.....I believe in employing the "kiss principle" and thus my reply

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Dr.SteelheadCatcher
Warrenton, OR

I believe that the more info, the better! Good stuff guys, thanks!

The battery i'm running is a, REMCO RM 12-9HR (12V8AH/20HR) HIGH RATE
RECHARGEABLE VALUE REGULATED (SEALED) BATTERY
CONSTANT VOLTAGE CHARGE
VOLTAGE REGULATION 13.50-13.80V (STAND-BY USE) and 14.40-14.70V (CYCLIC USE)
INITIAL CURRENT 2.4A MAX

Having read the above posts, is it better to trickle charge it, as opposed to charging it full then having it sit all week?

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2015 PA 12 OLIVE

I use a Battery Tender Junior charger. It has a max output of 750mA so gentle on the smaller sealed batteries and implements the multi-stage charging cycle that's best for lead-acid batteries. It does a bulk then absorption stage to get the battery fully charged then drops down to a "float" voltage that's safe to leave connected to the battery.

I don't leave mine connected though, just charge it up until it's in float then disconnect and let it sit until I use it again. If I go more than a month between uses I'll reconnect the Battery Tender to make sure it's topped up.

Thanks for the info!!

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2015 PA 12 OLIVE