KG
Any local Batteries Plus can rebuild battery packs. http://www.batteriesplus.com/
----- Original Message ----
From: Rick Johnson
To: Todd.Dye@CH2M.com
Cc: obra@list.obra.org
Sent: Monday, September 18, 2006 3:35:55 PM
Subject: [OBRA Chat] Batteries and such
In case anybody would like to take on repairing their rechargeable battery packs it's not very difficult. The majority of problems are related to the batteries and a fresh set will often fix the problems. This is especially true of NiCads since they have a more limited number of charge/discharge cycles and will also develop a memory (false full & empty "thresholds"). If you're handy with some simple tools and have a soldering iron don't be afraid to cut those packs open. What you'll find inside is almost always commonly available cell sizes. The only difference is that they'll usually be "tabbed" for easy solder assembly. Replacements are available from a variety of online distributors. Just replace the old cells and use some plastic glue to close the case back up. I can provide resources on request.
A little bit more about battery chargers and why you get what you pay for (or don't). You'd think charging a battery would be as simple as discharging one. Unfortunately it's not the case.
The most primitive chargers (so called "slow chargers") are based on a calculation of the maximum amount of current (in milli amps or mA) the target number of cells can accept for an extended period of time without damaging the cells. These are the safest and cheapest option as they are unsophisticated and can't push enough current to damage the cells. They are also very, very slow to bring the batteries to full charge and as the cells age these chargers have increasing trouble with getting the cells up to their maximum capacity.
Everything up from there gets more complicated. Every cell type has a "charge profile" - the maximum amount of current the cell can handle at different states of charge. Some inexpensive "fast chargers" will make some crude assumptions about the state of the batteries and force current in on a tiered profile. This may work fine for a while but repeatedly hitting the batteries with too much current damages the cells (primarily through overheating) and shortens their life.
The latest development is "smart chargers". They work by utilizing a IC microcontroller that cycles the charger through a pattern of charge/pause/test to monitor the cell voltage thereby tracking the charge profile as the battery is charged. They will actively change the current to meet the needs of the cells being charged. Generally, if well designed, these systems give the best balance of fast charge time, full state of charge and minimal stress to the cells. They are not cheap - but you get what you pay for.
And bear in mind that with any type of charger once there is a problem with any of the cells it throws the system out of balance. If one cell of the battery won't accept the current it is generally going to go to the others. Even with a smart charger cell voltage will test inaccurately. Eventually all the cells will be damaged. As the charging circuit is generally protected and robust most problems are therefore correctable with new cells.
Rick
Todd.Dye@CH2M.com wrote: _filtered { font-family:Arial Black; } _filtered {margin:1.0in 1.25in 1.0in 1.25in;} P.MsoNormal { FONT-SIZE:12pt;MARGIN:0in 0in 0pt;FONT-FAMILY:"Times New Roman";} LI.MsoNormal { FONT-SIZE:12pt;MARGIN:0in 0in 0pt;FONT-FAMILY:"Times New Roman";} DIV.MsoNormal { FONT-SIZE:12pt;MARGIN:0in 0in 0pt;FONT-FAMILY:"Times New Roman";} A:link { COLOR:blue;TEXT-DECORATION:underline;} SPAN.MsoHyperlink { COLOR:blue;TEXT-DECORATION:underline;} A:visited { COLOR:purple;TEXT-DECORATION:underline;} SPAN.MsoHyperlinkFollowed { COLOR:purple;TEXT-DECORATION:underline;} P.MsoAutoSig { FONT-SIZE:12pt;MARGIN:0in 0in 0pt;FONT-FAMILY:"Times New Roman";} LI.MsoAutoSig { FONT-SIZE:12pt;MARGIN:0in 0in 0pt;FONT-FAMILY:"Times New Roman";} DIV.MsoAutoSig { FONT-SIZE:12pt;MARGIN:0in 0in 0pt;FONT-FAMILY:"Times New Roman";} SPAN.EmailStyle17 { FONT-WEIGHT:normal;COLOR:navy;FONT-STYLE:normal;FONT-FAMILY:Arial;TEXT-DECORATION:none;} DIV.Section1 { } Keith,
I don't want to scare you completely away from NiMH batteries, I just wanted to give you fair warning that they aren't perfect like the marketing department would have you believe. Most likely the problems you've experienced with your niterider system are with the crappy electronics not so much the NiCad battery. I ran a digital niterider with a NiMH battery and have a number of friends who have also, and we've all had problems like you mention. Hopefully niterider has gotten those issues corrected, but it would take a lot of convincing to get me to try another one.
I have an 18 mile round trip commute with about 4 of those miles in city traffic, and the rest a mix of moderately traveled roads and some really narrow dark country lanes with next to no traffic. I've got lots of hills to deal with including a 19% grade 45mph roller coaster with a stop sign at the bottom. It's such a varied mix of conditions I really get a good feel for what does and doesn't work.
When I'm not running a HID, I use a Dinotte Ultra 3 Watt LED, and I like it a lot. The 3W doesn't cut it at speeds above 25 mph, but I'm not comfortable at those speeds with my 10 W or 15W halogen either. I'd say the 3 watt LED is comparable to about a 10W halogen, maybe a little less. The Dinotte Ultra 5 watt LED puts out a bit more light with a wider beam pattern, and is probably more comparable to a 15W halogen with a flood pattern. It doesn't project as far as a 15W halogen with a spot beam.
The nice thing about the Dinotte lights is that they run on 4 AA NiMH batteries. The beauty there is that you can carry an extra set of batteries in your pack an extra set of AAs as a backup with minimal weight penalty. And the battery packs are so small compared to a big water bottle battery. I Velcro the battery under my stem and it's completely out of the way. I like running the Dinotte in spring and fall when it may not be full on dark in both directions on my commute, so I'm not carrying the extra weight and bulk of the HID when I don't really need that much light. It's also great for late evening training rides in case you don't get home in time since it's so non-intrusive on the bike and fits easily into a jersey pocket as well.
The other thing I really like is that since the Dinotte uses 4AAs, if your batteries take a crap, you can get replacement NiMH batteries (and spare charger) for really cheap (maybe $20 to $25) compared to replacing a $80 to $100+ water bottle battery. I've got a charger at home and one in my office, so I'm always able to charge batteries and run spares since I've got a boatload of spare battereis for my digital camera.
When I'm using the HID, I put the Dinotte in my pack as a backup.
You are the only one who knows how much light you need for the conditions you ride in. Some people are happy with the $20 throw away LED lights out there and others insist that a $500+ HID is a must.
If you can find a shop that will let you test out some lights in person that would be your best bet. Take two systems out at a time if they'll let you and switch back and forth.
-Todd
From: obra-bounces@list.obra.org [mailto:obra-bounces@list.obra.org] On Behalf Of Keith A. Prior
Sent: Monday, September 18, 2006 1:17 PM
To: obra@list.obra.org
Subject: Re: [OBRA Chat] lights and such
Thank you everyone who has responded.
My main reason for switching to NMHi batteries is to not have to use that dreadful
60 pound water bottle size battery. But some have mentioned that their old clunker
NiCad batteries have outlasted a drawer full of the newer NiMHi batteries and that
makes me rethink this whole switch.
I do need a light that can really light up the road as I often commute through Washington
park and its REALLY dark up there during the fall winter months and you need positive
ground illumination. Also when bombing down Cornell rd with wet glasses and headlight
glare you really need the road illumination.
I have been happy with my 15W halogen that I run on flasher (dont get cute) mode but oooh..
that battery!!
For the most part my NiteRider NiCad works good except for the big honkin' battery and that little
lying charge indicator. You would be amazed how many times I have that on charge all night
and I get up in the morning, turn it on and it reads a full charge then I turn it off, get ready
and go out the door to find it showing RED. AGHH!!!
-K
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