03-21-2008, 11:32 AM
Hi Don
That was me.
You will need 10 (not 8) nimh cells in the pack to get the 12 volts the sonar wants.
The current drain is between 0.5 amps and 0.75 amps for sonar units up to 1500W peak-to-peak with the backlight on.
Generally the "fat cells" (high discharge) are tougher and the "skinny cells" (high capacity) are weaker.
Sticking to AA size cells - I have tested the Sanyo 2500HR3Us and 2100HR3Us and they are robust enough to maintain a 1.5 amp drain without voltage brownout.
The di
vantage with AA size is it can't be recharged as fast as the fatter cells, and needs to be done slower taking about 2 hours at home. For this reason I prefer a thicker cell.
The 2/3rds A size (like a slightly fatter AA but shorter length) KAN1100s, GP1300s are all much handier than AA for the float tuber.
That's because they are a technically superior shape, and therefore can be recharged in as little as 30-45 minutes (from flat to full) with a delta peak charger from automotive battery in the field.
That makes these cells particularly good for our use. Since the time it takes to have a cup of coffee and a sandwich can refill the battery completely.
The next size up again - short C type - GP2200s and KAN2200s, are excellent ... all the full C size GP3300s, GP3700s, Panasonic 3000s and Sanyos are good too.
All those 10 cell packs are 1/10th the weight to 1/3rd the weight of lead acid packs, and recharge ten times faster, but cost double to triple the cost of SLA cells.
Hope this helps.
[signature]
That was me.
You will need 10 (not 8) nimh cells in the pack to get the 12 volts the sonar wants.
The current drain is between 0.5 amps and 0.75 amps for sonar units up to 1500W peak-to-peak with the backlight on.
Generally the "fat cells" (high discharge) are tougher and the "skinny cells" (high capacity) are weaker.
Sticking to AA size cells - I have tested the Sanyo 2500HR3Us and 2100HR3Us and they are robust enough to maintain a 1.5 amp drain without voltage brownout.
The di
vantage with AA size is it can't be recharged as fast as the fatter cells, and needs to be done slower taking about 2 hours at home. For this reason I prefer a thicker cell. The 2/3rds A size (like a slightly fatter AA but shorter length) KAN1100s, GP1300s are all much handier than AA for the float tuber.
That's because they are a technically superior shape, and therefore can be recharged in as little as 30-45 minutes (from flat to full) with a delta peak charger from automotive battery in the field.
That makes these cells particularly good for our use. Since the time it takes to have a cup of coffee and a sandwich can refill the battery completely.
The next size up again - short C type - GP2200s and KAN2200s, are excellent ... all the full C size GP3300s, GP3700s, Panasonic 3000s and Sanyos are good too.
All those 10 cell packs are 1/10th the weight to 1/3rd the weight of lead acid packs, and recharge ten times faster, but cost double to triple the cost of SLA cells.
Hope this helps.
[signature]