Battery question

[BCDave]

Originally Posted by Kip in Ga.

According to the battery page posted above. A flooded battery will typically self discharge about 1% per day. Depending on ambient temperature.

So yes, as McDenny said, in 3-4 months a flooded battery would be pretty much discharged. That would very likely be true whether it be a deep cycle or a car battery.

On the other hand, an AGM car battery would likely behave the same as a deep cycle AGM battery and discharge much slower.

Question is, do they even make AGM car batteries? Realizing there have been maintenance free car batteries around for years. Such as the Sears "Die Hard". Are they AGM or simply flooded batteries that are somehow sealed?

A cheap-o car battery would work fine in a camper that was plugged into camp power, but would likely have a shorter life than a more expensive one. Also IF camp power went out for several hours, and a fantastic fan and light were burning, the car battery might not do well.
Construction of car batteries and Deep Cycles are different as they have different jobs.

Another thought:

The more expensive and better quality chargers have buttons or switches for selecting Flooded or Gel or AGM. According to my "Battery Minder" charger/desulfinator, the 3 types need to be charged at different rates and/or at different cut off points.

The power supply in my 2003 Casita doesn't give me those options. I don't know if it is a multi-stage charger or single stage. AGMs were not as plentiful in 2003 as they are now. So could the camper charger do justice to an AGM or even damage it?

Kip

Optima makes 3 types of AGM batteries.

One (red top) is for car use - it is a starting battery.

One is "dual purpose" marine (blue top) - ie a combo deep cycle/starting battery

One is a pure deep cycle (yellow top)

I used a blue top for years and years, and despite my abuse of it by deep - discharging and fast recharging with a high-output single-stage charger. it is still going strong.

[Byron Kinnaman]

Originally Posted by BCDave

Optima makes 3 types of AGM batteries.

One (red top) is for car use - it is a starting battery.

One is "dual purpose" marine (blue top) - ie a combo deep cycle/starting battery

One is a pure deep cycle (yellow top)

I used a blue top for years and years, and despite my abuse of it by deep - discharging and fast recharging with a high-output single-stage charger. it is still going strong.

According to the Optima web site they don't make a "pure deep cycle" battery. The closest is a blue top.
The C/20 rating (typical amp hour rating) is close to 1/2 that of a flooded cell battery of same size. i.e., Group 27 flood cell about 105 amp hour, Group 27 Optima 66 amp hours.

My original group 24 74 amp hour battery provided good service for 5 years. Replacement cost about $60.00
Optima Blue top DM27 (that's the smallest) cost close to $200. Expected life according some sources is about 4 years. Even if it 5 years, what's point other than putting more money into the economy?

Sometimes more expensive doesn't equate to better.